Vertical root fracture (VRF) is one of significant problems of the endodontic failure. Understanding of mechanism and initiated location of VRF may be crucial for prevention. The initiated location of VRF may involve in mechanical properties of dentin. Peritubular and intertubular root dentin have been reported to affect hardness and strength of dentin. The purpose of this study was to compare the amount and composition, calcium and phosphorous, of peritubular and intertubular root dentin at cervical third, middle third and apical third of root dentin from the same distance from root canal. Ten extracted human upper incisor roots were used in this study. Each root was cut into three parts as cervical, middle and apical third. Each part was cut along long axis again into two small parts in mesio-distal direction. The first part was cut approximately 1 mm from root canal and the second one at the middle location between root canal and cementodentinal junction. The amount of peritubular and intertubular root dentin was examined by using SEM with the same magnification and calculated by mathematic method. The amount of calcium and phosphorous was measured by using EDS machine. The results were analyzed by using One-way ANOVA and found that quantity and composition of peritubular and intertubular root dentin at cervical third, middle third and apical third from the same distance from root canal were not significant (p>0.05) This result suggests that the location along the root axis should not be a predisposing factor of VRF, regarding to amount and composition of peritubular and intertubular root dentin.

The purpose of this in vitro study was to determine the antibacterial effects of Streblus asper leaf extract against five anaerobic bacteria often found in pulpal pathology which were Porphyromonas gingival, Prevotella intermedia, Actinomyces anaeslundii, Actinobacillus actinomycetemcomitans and Peptostreptococcus micros. Employing the disc diffusion method, the results showed that 15 µl of the S. asper leaf extract at concentrations 250 and 500 mg/ml possessed inhibitory effects towards all bacterial strains tested. The minimum inhibitory concentrations of S. asper leaf extract in P. gingivalis, A. actinomycetemcomitans. P.micros, P.intrmedia, and A.naeslundii were 3.91, 7.81, 15.62, 31.25 and 125 mg/ml respectively. While the minimum bactericidal concentrations of the extract on A. actinomycetemcomitans, P.gingivalis and P.micros were 15.62, 31.25 and 62.5 mg/ml respectively, the extract has no bacterial activity against P.intermedia and A.naeslundii.

The present study was to assess the effectiveness of Haiter® used as an endodontic irrigant. In vitro study was performed to compare the antimicrobial property and tissue dissolving ability of Haiter® and Clorox®. Prior to the experimental procedure, these bleaching agents were diluted to the concentration of 2.5% solutions. The efficacy of the antimicrobial activity was evaluated by determining the growth of two microorganisms. Absorbed paper points were contaminated with Enterococcus faecalis and Candida albicans in the test solutions at different time intervals of 1, 5, 15 and 30 minutes. The point were then transferred to the Trypticase Soy Broth and incubated. The presence or absence of microbial growth was recorded. The tissue dissolving ability was investigated by determining the mean percentage of desiccated tissue weight change after exposing boving pulp tissue to each test solution for 15 minutes. The results demonstrated that Haiter® was significantly more effective than Clorox® in tissue dissolving ability (p<0.05). In addition, Haiter® could inhibit growth of Candida albicans and Enterococcus faecalis within 1 and 5 minutes, respectively. The growth of both organisms was inhibited after a 1-minute exposure to Clorox®. It is concluded that Haiter® was effective in both tissue dissolving ability and antimicrobial property and could be used as an alternative to Clorox® in root canal irrigation.The present study was to assess the effectiveness of Haiter® used as an endodontic irrigant. In vitro study was performed to compare the antimicrobial property and tissue dissolving ability of Haiter® and Clorox®. Prior to the experimental procedure, these bleaching agents were diluted to the concentration of 2.5% solutions. The efficacy of the antimicrobial activity was evaluated by determining the growth of two microorganisms. Absorbed paper points were contaminated with Enterococcus faecalis and Candida albicans in the test solutions at different time intervals of 1, 5, 15 and 30 minutes. The point were then transferred to the Trypticase Soy Broth and incubated. The presence or absence of microbial growth was recorded. The tissue dissolving ability was investigated by determining the mean percentage of desiccated tissue weight change after exposing boving pulp tissue to each test solution for 15 minutes. The results demonstrated that Haiter® was significantly more effective than Clorox® in tissue dissolving ability (p<0.05). In addition, Haiter® could inhibit growth of Candida albicans and Enterococcus faecalis within 1 and 5 minutes, respectively. The growth of both organisms was inhibited after a 1-minute exposure to Clorox®. It is concluded that Haiter® was effective in both tissue dissolving ability and antimicrobial property and could be used as an alternative to Clorox® in root canal irrigation.

The purpose of this study were to identify factors associated with the demands for orthodontic treatment, to assess the needs for orthodontic treatment and to study the relationship between demands and needs for orthodontic treatment. The samples were 204 Thais, aged between 12-22 years old, who had demanded for orthodontic treatment. They were asked to complete questionnaires for studying factors and demands for the treatment. Impressions for diagnostic models were taken to assess the needs for treatment by using Dental Aesthetic Index (DAI). Results showed that factors associated with the patients demands for orthodontic treatment consisted of satisfaction with tooth alignment, and understanding of normal dental alignment, a perception on maxillary dental protrusion, and experience of being teased by other persons, being teased that affected confidence and self-confidence in tooth alignment. By using DAI, an average of the needs for orthodontic treatment was 33.0. There was a low correlation between demands and needs for orthodontic treatment (r=0.119, p=0.093). The results indicated that an education on normal occlusion and malocclusion should be provided to the patients in order that they will obtain the most effective treatment without any unnecessary payment.The purpose of this study were to identify factors associated with the demands for orthodontic treatment, to assess the needs for orthodontic treatment and to study the relationship between demands and needs for orthodontic treatment. The samples were 204 Thais, aged between 12-22 years old, who had demanded for orthodontic treatment. They were asked to complete questionnaires for studying factors and demands for the treatment. Impressions for diagnostic models were taken to assess the needs for treatment by using Dental Aesthetic Index (DAI). Results showed that factors associated with the patients demands for orthodontic treatment consisted of satisfaction with tooth alignment, and understanding of normal dental alignment, a perception on maxillary dental protrusion, and experience of being teased by other persons, being teased that affected confidence and self-confidence in tooth alignment. By using DAI, an average of the needs for orthodontic treatment was 33.0. There was a low correlation between demands and needs for orthodontic treatment (r=0.119, p=0.093). The results indicated that an education on normal occlusion and malocclusion should be provided to the patients in order that they will obtain the most effective treatment without any unnecessary payment.

The objective of this study was to obtain oral status and some factors affecting oral health of the seventh grade schoolchildren. The survey included 1,110 students aged range of 11-15 years old. The multi-stage random sampling technique was used. The study revealed that prevalence of dental caries were 81.1% and means DMFT and DMFS were 3.46 (teeth/person) and 5.47 (surfaces/person) respectively. The means DMFT and DMFS of girls were statistically higher than boys. The percentage of children who had plaque index score 2 was 68.2. The prevalence of gingival index score 2 was 61.7%. There was no statistical difference of gingivitis between sexes. The percentage of students who had supra-gingival calculus was 80.5. The mean areas of teeth having supra-gingival calculus were 4.31 areas of teeth/person (from 12 areas of teeth/person), and the calculus was 93.06 with the mean 6.05 areas of teeth/person. The treatment need for dental decay was one surface filling with the average of 2 teeth/person. Other factors about dental health are demographic, diet consumption behavior, tooth brushing and other dental health behaviors and dental health program in schools. The findings are used for planning a dental health program for secondary school students in the national dental health plan under the ninth national economic and social plan.The objective of this study was to obtain oral status and some factors affecting oral health of the seventh grade schoolchildren. The survey included 1,110 students aged range of 11-15 years old. The multi-stage random sampling technique was used. The study revealed that prevalence of dental caries were 81.1% and means DMFT and DMFS were 3.46 (teeth/person) and 5.47 (surfaces/person) respectively. The means DMFT and DMFS of girls were statistically higher than boys. The percentage of children who had plaque index score 2 was 68.2. The prevalence of gingival index score 2 was 61.7%. There was no statistical difference of gingivitis between sexes. The percentage of students who had supra-gingival calculus was 80.5. The mean areas of teeth having supra-gingival calculus were 4.31 areas of teeth/person (from 12 areas of teeth/person), and the calculus was 93.06 with the mean 6.05 areas of teeth/person. The treatment need for dental decay was one surface filling with the average of 2 teeth/person. Other factors about dental health are demographic, diet consumption behavior, tooth brushing and other dental health behaviors and dental health program in schools. The findings are used for planning a dental health program for secondary school students in the national dental health plan under the ninth national economic and social plan.

The purpose of this study was to investigate Convergence angle of abutment for crown and bridge work prepared by the forth year dental students, Faculty of Dentistry, Prince of Songkla University. The results were compared with ideal convergence angle and minimal convergence angles recommended for successful clinical practice. Samples were only the abutments prepared in laboratory practice hours that were passed the final evaluation as good abutments by the supervisors. Ninety-six abutments comprised eleven upper right central incisors, thirty-three upper right canines and forty-eight lower right first molars. Photographs were taken of all abutments at proximal and buccal aspects and then measured the angle formed by intersection of the opposing tooth preparation walls with a protractor. Results revealed that the average convergence angle was 12.65 9.42 degrees, which was larger than ideal convergence angle but was still in the range of recommended minimal convergence angle for clinical success.The purpose of this study was to investigate Convergence angle of abutment for crown and bridge work prepared by the forth year dental students, Faculty of Dentistry, Prince of Songkla University. The results were compared with ideal convergence angle and minimal convergence angles recommended for successful clinical practice. Samples were only the abutments prepared in laboratory practice hours that were passed the final evaluation as good abutments by the supervisors. Ninety-six abutments comprised eleven upper right central incisors, thirty-three upper right canines and forty-eight lower right first molars. Photographs were taken of all abutments at proximal and buccal aspects and then measured the angle formed by intersection of the opposing tooth preparation walls with a protractor. Results revealed that the average convergence angle was 12.65 9.42 degrees, which was larger than ideal convergence angle but was still in the range of recommended minimal convergence angle for clinical success.

This retrospective study was aimed to analyze the lesions previously diagnosed as globulomaxillary cyst. The data were collected from the biopsies of the Department of Oral Pathology, Chulalongkorn University from 1969 to 1999. Eighteen cases of globulomaxillary cyst were recruited from 3,890 cysts of the jaw bone and oral cavity and reviewed by light microscope according to the World Health Organization classification. Clinical features, location of the cyst, the vitality of teeth and radiographic features were studied. Results revealed that there were five cases of radicular cyst, two cases of nasolabial cyst, two cases of residual cyst, on case of nasopalatine cyst, one case of dentigerous cyst, one case of lateral periodontal cyst, one case of odontogenic keratocyst, four cases of uncertain origin and one case of ameloblastoma. It could be concluded that most of the cases were odontogenic in origin, however, a few cases remained uncertain. More information and details of the case history including clinical features, vitality of the tooth involved and radiographic feature are required from the dentist who biopsied the specimen. The findings of this study advocate the deletion of this cyst from the new classification and indicate that the fissural origin of this cyst is a misconception.This retrospective study was aimed to analyze the lesions previously diagnosed as globulomaxillary cyst. The data were collected from the biopsies of the Department of Oral Pathology, Chulalongkorn University from 1969 to 1999. Eighteen cases of globulomaxillary cyst were recruited from 3,890 cysts of the jaw bone and oral cavity and reviewed by light microscope according to the World Health Organization classification. Clinical features, location of the cyst, the vitality of teeth and radiographic features were studied. Results revealed that there were five cases of radicular cyst, two cases of nasolabial cyst, two cases of residual cyst, on case of nasopalatine cyst, one case of dentigerous cyst, one case of lateral periodontal cyst, one case of odontogenic keratocyst, four cases of uncertain origin and one case of ameloblastoma. It could be concluded that most of the cases were odontogenic in origin, however, a few cases remained uncertain. More information and details of the case history including clinical features, vitality of the tooth involved and radiographic feature are required from the dentist who biopsied the specimen. The findings of this study advocate the deletion of this cyst from the new classification and indicate that the fissural origin of this cyst is a misconception.

Oral transmission of HIV among adults has been a controversial issue. The complexity of human sexual behavior makes the identification of those who engage only in oral-genital contact difficult. Most epidemiologic studies have not had sufficient power to detect transmission or to reject the hypothesis that transmission does occur. An animal model of oral HIV transmission has also been performed, but no concrete conclusion could be made so far. At present the exact mechanism of HIV transmission after exposure to oral mucous membrane surface to HIV-infected secretions is unknown. Several studies revealed that most of the HIV infectivity occurs as infected leukocytes rather than as cell-free HIV. Thus, these infectious leukocytes have been proposed to be a major transmitting mechanism at mucosal surface. Despite detectable virus in saliva and oropharyngeal tissues of infected individuals, oral cavity is rarely a site of HIV transmission. A number of antiviral components in saliva have been documented including secretory leukocytes protease inhibitors (SLPI). The unique hypotonicity of saliva has also been proposed as a major mechanism by which saliva inactivates transmitting leukocytes and prevents their attachment to mucosal epithelial cells. However, these may be overcome by the volume effects of seminal fluid resulting in the oral HIV transmission. Further studies are needed to confirm the proposed mechanism.

The objective of this study was to document the attitudes and behaviour of HIV-infected patients in regard to their oral health service experiences, and the related social impacts. A total of 135 HIV-infected patients attending the HIV clinics in two government hospitals in southern Thailand were interviewed with a structured questionnaire to reveal their attitudes and behaviour in regard to dental treatment. Patient expectations were; to be treated like any other patients 109/135 cases (81%), to receive help with treatment costs 104/135 cased (77%) and to be given homecare instruction for oral hygiene management 94/135 cases (70%). The behavioural and social information of 17 cases diagnosed less than one month was excluded due to concern about the reliability of this information. After their HIV diagnosis, only 30/118 cases (25%) had visited a dentist, although 36/118 cases (53%) had experienced oral mucosal symptoms. Among those who visited a dentist, 22/30 cased (73%) did not disclose their HIV status. Sixty seven of 118 cases (57%) did not know the HIV status of their spouse or other family members. Seventy two of 118 cases (61%) had economic problems but only 36 cases(31%) had ever received help. Providing preventive measures and oral health treatment, together with emotional support and acceptance from oral health personnel (OHP), are needed to improve patients attitude and the management of the HIV-patient group. Financial support including help with the treatment cost is also an important concern for these patients.The objective of this study was to document the attitudes and behaviour of HIV-infected patients in regard to their oral health service experiences, and the related social impacts. A total of 135 HIV-infected patients attending the HIV clinics in two government hospitals in southern Thailand were interviewed with a structured questionnaire to reveal their attitudes and behaviour in regard to dental treatment. Patient expectations were; to be treated like any other patients 109/135 cases (81%), to receive help with treatment costs 104/135 cased (77%) and to be given homecare instruction for oral hygiene management 94/135 cases (70%). The behavioural and social information of 17 cases diagnosed less than one month was excluded due to concern about the reliability of this information. After their HIV diagnosis, only 30/118 cases (25%) had visited a dentist, although 36/118 cases (53%) had experienced oral mucosal symptoms. Among those who visited a dentist, 22/30 cased (73%) did not disclose their HIV status. Sixty seven of 118 cases (57%) did not know the HIV status of their spouse or other family members. Seventy two of 118 cases (61%) had economic problems but only 36 cases(31%) had ever received help. Providing preventive measures and oral health treatment, together with emotional support and acceptance from oral health personnel (OHP), are needed to improve patients attitude and the management of the HIV-patient group. Financial support including help with the treatment cost is also an important concern for these patients

This in vitro study investigated the effect of dentine bonding agent, Single bond® (3M ESPE, USA) on microleakage of pit and fissure sealants bonded to salivary contaminated enamels. Newly extracted 40 carious-free human upper premolar teeth were divided into four groups of 10 each. Group 1 pit and fissure sealants were applied directly to etched enamels then light cured. Group 2 etched enamel surfaces were contaminated with saliva before applied with pit and fissure sealants. Group 3 etched enamel surfaces were contaminated with saliva, then applied bonding agent (Single bond®) and light cured before applied with pit and fissure sealant. Group 4 the specimen were recontaminated with saliva after applied bonding agent then applied with pit and fissure sealant. Microleakage was evaluated by measured the distance of dye penetration on the mesial and distal aspects of the sealant-enamel interface under microscope. The results revealed a statistically significant difference between the microleakage of the salivary contaminated and uncontaminated group. Placement of Sing bond® as intermediate layer between the sealant and contaminated enamel surfaces reduced microleakage of pit and fissure sealant. Salivary contaminated enamel microleakage of the sealant-enamel interface. After applied single bond on contaminated enamel reduce microleakage of pit and fissure sealants.This in vitro study investigated the effect of dentine bonding agent, Single bond® (3M ESPE, USA) on microleakage of pit and fissure sealants bonded to salivary contaminated enamels. Newly extracted 40 carious-free human upper premolar teeth were divided into four groups of 10 each. Group 1 pit and fissure sealants were applied directly to etched enamels then light cured. Group 2 etched enamel surfaces were contaminated with saliva before applied with pit and fissure sealants. Group 3 etched enamel surfaces were contaminated with saliva, then applied bonding agent (Single bond®) and light cured before applied with pit and fissure sealant. Group 4 the specimen were recontaminated with saliva after applied bonding agent then applied with pit and fissure sealant. Microleakage was evaluated by measured the distance of dye penetration on the mesial and distal aspects of the sealant-enamel interface under microscope. The results revealed a statistically significant difference between the microleakage of the salivary contaminated and uncontaminated group. Placement of Sing bond® as intermediate layer between the sealant and contaminated enamel surfaces reduced microleakage of pit and fissure sealant. Salivary contaminated enamel microleakage of the sealant-enamel interface. After applied single bond on contaminated enamel reduce microleakage of pit and fissure sealants.

The purpose of this longitudinal descriptive study were to survey oral health status and salivary factors in pregnant women and followed the variable value changes when the gestation periods of the subjects were in progress. Subjects were 1 trimester pregnant women who attended the ante natal care unit at Mother and Child Hospital, Chiang Mai. Subjects were interviewed and orally examined to determine caries experiences, plaque status, gingival status, and calculus status. Saliva samples of subjects were collected to determine flow rate, pH, and the quantities of Streptococcus mutans. Plaque status gingival status, and salivary factor determinations were repeated when the subjects gestation periods were in 2 and 3 trimester. Data were collected by questionnaire and oral health and salivary factor record forms Data were analyzed by using descriptive statistics, and non-parametric Friedman Two-Way Analysis of Variance by Ranks was used to compare the variables. The results revealed that the 104 subjects were in the age range of 16-39 years. Mean DMFT and DMFS of the subjects were 5.7±4.5 and 10.4±11.7. Mean plaque index score, gingival index score, and calculus index score were 1.16±0.30, 1.49±0.52, and 1.64±0.62 respectively. There were no significant differences of plaque index scores, gingival index scores and salivary flow rates among the 3 gestation periods while significant differences of pH of unstimulated and stimulated saliva were found at p-value = 0.000 and 0.035 respectively. The percentage of the subjects who harbored S.mutans in saliva of>8x10³ cfu/ml were 75.96, 73.44, 73.17 for the subjects in trimester 1. 2 and 3 respectively. The results indicated that oral health status and salivary factors except salivary pH of the subjects did not change when the gestation periods were in progress. However, dental prevention measures are still needed in pregnant women.The purpose of this longitudinal descriptive study were to survey oral health status and salivary factors in pregnant women and followed the variable value changes when the gestation periods of the subjects were in progress. Subjects were 1 trimester pregnant women who attended the ante natal care unit at Mother and Child Hospital, Chiang Mai. Subjects were interviewed and orally examined to determine caries experiences, plaque status, gingival status, and calculus status. Saliva samples of subjects were collected to determine flow rate, pH, and the quantities of Streptococcus mutans. Plaque status gingival status, and salivary factor determinations were repeated when the subjects gestation periods were in 2 and 3 trimester. Data were collected by questionnaire and oral health and salivary factor record forms Data were analyzed by using descriptive statistics, and non-parametric Friedman Two-Way Analysis of Variance by Ranks was used to compare the variables. The results revealed that the 104 subjects were in the age range of 16-39 years. Mean DMFT and DMFS of the subjects were 5.7±4.5 and 10.4±11.7. Mean plaque index score, gingival index score, and calculus index score were 1.16±0.30, 1.49±0.52, and 1.64±0.62 respectively. There were no significant differences of plaque index scores, gingival index scores and salivary flow rates among the 3 gestation periods while significant differences of pH of unstimulated and stimulated saliva were found at p-value = 0.000 and 0.035 respectively. The percentage of the subjects who harbored S.mutans in saliva of>8x10³ cfu/ml were 75.96, 73.44, 73.17 for the subjects in trimester 1. 2 and 3 respectively. The results indicated that oral health status and salivary factors except salivary pH of the subjects did not change when the gestation periods were in progress. However, dental prevention measures are still needed in pregnant women.

Multiple myeloma is a malignant tumor of bone resulting from the clonal proliferation of terminally differentiated B cells or plasma cells. A rare case of multiple myeloma involveng the maxilla is presented. A 61-year-old male patient had a chief complaint of pain and swelling of the left anterior maxilla. Biopsy of the lesion revealed a tumor of plasma cells which elaborated only a single type of immunoglobulin. Thorough history taking, physical examination, roentgenographic and laboratory investigations confirmed the diagnosis of multiple myeloma. This case is a fine example of the fact that an oral lesion can lead to the diagnosis of life- threatening, systemic disease.

Schwannoma is a benign of Schwann cells. It is a rare tumour for intra-oral location. Three cases were reported here. They were present at the lip, in the mandible and at the palate. The ages of the patients were 19, 50 and 18 years, respectively. Each tumour exhibited different microscopic features including classic, cellular and ancient types. The Masson trichrome staining and S-100 protein immunostaining were used to support the diagnoses. Clinicopathological features of intra-oral schwannomas from the three cases were studied and compared with 223 cases in the English literature. Oral pathologists should be aware of the rarity of intra-oral schwannoma together with the potential to encounter its variants in order to achieve the accurate diagnosis and treatment.Schwannoma is a benign of Schwann cells. It is a rare tumour for intra-oral location. Three cases were reported here. They were present at the lip, in the mandible and at the palate. The ages of the patients were 19, 50 and 18 years, respectively. Each tumour exhibited different microscopic features including classic, cellular and ancient types. The Masson trichrome staining and S-100 protein immunostaining were used to support the diagnoses. Clinicopathological features of intra-oral schwannomas from the three cases were studied and compared with 223 cases in the English literature. Oral pathologists should be aware of the rarity of intra-oral schwannoma together with the potential to encounter its variants in order to achieve the accurate diagnosis and treatment.

Cellular mixed tumor is a variant of benign mixed tumor: A case of cellular mixed tumor from the palate is reported here. Histologically, the tumor mass consisted of 2 patterns, identified by the authors as pattern A and B. In pattern A, the epithelial component occupied more than 80% of the tumor bulk while the stromal component was hardly detected. In pattern B, the epithelial component constituted approximately 40-60% of the tumor and the myxoid stroma was clearly illustrated. Thorough examination of several sections revealed that the majority of the tumor was histologically corresponding to pattern A. Tumor cells did not invade adjacent salivary gland, nerves and blood vessels. Immunohistochemical analysis showed positive staining for both S-100 protein and glial fibrillary acidic protein (GFAP) but the staining pattern was different. There were 2 important aspects of cellular mixed tumors that should be considered. Firstly, this tumor might be misdiagnosed as malignancy. Secondly, the malignant potential is some cellular mixed tumors does exist, in particular in those demonstrating high mitotic activity. Although treatment of cellular mixed tumors is conservative, follow up must be strictly controlled.Cellular mixed tumor is a variant of benign mixed tumor: A case of cellular mixed tumor from the palate is reported here. Histologically, the tumor mass consisted of 2 patterns, identified by the authors as pattern A and B. In pattern A, the epithelial component occupied more than 80% of the tumor bulk while the stromal component was hardly detected. In pattern B, the epithelial component constituted approximately 40-60% of the tumor and the myxoid stroma was clearly illustrated. Thorough examination of several sections revealed that the majority of the tumor was histologically corresponding to pattern A. Tumor cells did not invade adjacent salivary gland, nerves and blood vessels. Immunohistochemical analysis showed positive staining for both S-100 protein and glial fibrillary acidic protein (GFAP) but the staining pattern was different. There were 2 important aspects of cellular mixed tumors that should be considered. Firstly, this tumor might be misdiagnosed as malignancy. Secondly, the malignant potential is some cellular mixed tumors does exist, in particular in those demonstrating high mitotic activity. Although treatment of cellular mixed tumors is conservative, follow up must be strictly controlled.

The purpose of this study was to evaluate the shear bond strength of high leucite content porcelain bonded to feldspathic porcelain using resin cement under different surface treatments. Three hundred high leucite porcelain discs (5.5 mm. in diameter and 1 mm. in thickness) were fabricated and divided into 5 groups having 5 surface treatments (60 discs/type): Type A) no additional surface treatment (a control group); Type B) polished with SiC paper; Type C) group with a coarse diamond bur; Type D) etched with 9.6% HF acid for 5 min. and Type E) etched with 1.23% APF gel for 10 min. Three hundred feldspathic porcelain discs (15 mm. in diameter and 1.5 mm. in thickness) were fabricated and divided into 6 groups (50 discs/group); Group 1) type A; Group 2) type B; Group 3) type C; Group 4) sandblasted with 50 µm aluminium oxide particles for 20 s; Group 5) type D and Group 6) type E. Feldspathic porcelain discs were then bonded to high leucite porcelain discs using resin cement under a load of 200 grams. All samples were subjected to shear bond strength evaluation using a universal testing machine (crosshead speed of 0.2 mm./min.). ANOVA and Tukey statistical analyses were performed on the data. There were b significant differences (p<0.05) in shear bond strengths (ranging from 26.7±6.1 to 30.1±3.7 MPa) among the groups that both bonding surfaces were relatively rough (Group A/3-6, C/3-6, D/3-6 and E/3-6). The bonding between a rough surface and a smooth one (Group A/1-2 B/1-6 C-E/1 and C-E/2) gave the lowest (P≤0.05) shear bond strengths (ranging from 15.9±1.8 to 22.3±3.1 MPa). High leucite content porcelain, therefore, is recommended to repair a porcelain-fractured restoration when both bonding surfaces are relatively rough.The purpose of this study was to evaluate the shear bond strength of high leucite content porcelain bonded to feldspathic porcelain using resin cement under different surface treatments. Three hundred high leucite porcelain discs (5.5 mm. in diameter and 1 mm. in thickness) were fabricated and divided into 5 groups having 5 surface treatments (60 discs/type): Type A) no additional surface treatment (a control group); Type B) polished with SiC paper; Type C) group with a coarse diamond bur; Type D) etched with 9.6% HF acid for 5 min. and Type E) etched with 1.23% APF gel for 10 min. Three hundred feldspathic porcelain discs (15 mm. in diameter and 1.5 mm. in thickness) were fabricated and divided into 6 groups (50 discs/group); Group 1) type A; Group 2) type B; Group 3) type C; Group 4) sandblasted with 50 µm aluminium oxide particles for 20 s; Group 5) type D and Group 6) type E. Feldspathic porcelain discs were then bonded to high leucite porcelain discs using resin cement under a load of 200 grams. All samples were subjected to shear bond strength evaluation using a universal testing machine (crosshead speed of 0.2 mm./min.). ANOVA and Tukey statistical analyses were performed on the data. There were b significant differences (p<0.05) in shear bond strengths (ranging from 26.7±6.1 to 30.1±3.7 MPa) among the groups that both bonding surfaces were relatively rough (Group A/3-6, C/3-6, D/3-6 and E/3-6). The bonding between a rough surface and a smooth one (Group A/1-2 B/1-6 C-E/1 and C-E/2) gave the lowest (P≤0.05) shear bond strengths (ranging from 15.9±1.8 to 22.3±3.1 MPa). High leucite content porcelain, therefore, is recommended to repair a porcelain-fractured restoration when both bonding surfaces are relatively rough.

This study aimed to compare the effect of using round-ended and coarse-cut bristle toothbrushes in plaque removal, gingival ulceration and abrasion of the bristles after a 40-day usage period. Quasi-experimental and crossover design with double blind technique were used with 73 subjects. All subjects had been randomly assigned to use one of the two types of toothbrushes--round-ended bristle and coarse-cut bristle--in the first session and switched to another type in the second session. Gingival ulcers and plaque scores (dye technique) were recorded before and after brushing in each session. Abrasion of the bristles was examined by connecting a microscope with a microcomputer. It was found that both types of bristle ends were able to remove dental plaque significantly (p<0.05) and not different in their cleansing efficiency. The new round-ended bristle caused less ulcers than the new coarse-cut bristle toothbrushes (p<0.05). No statistical difference in gingival ulceration was found after the 40-day usage of these two types of bristles. Microscopically, the abrasion of sharp edges was found in both bristle types but there was no difference in appearance found among bristles of the same type that caused ulcers and no ulcer.This study aimed to compare the effect of using round-ended and coarse-cut bristle toothbrushes in plaque removal, gingival ulceration and abrasion of the bristles after a 40-day usage period. Quasi-experimental and crossover design with double blind technique were used with 73 subjects. All subjects had been randomly assigned to use one of the two types of toothbrushes--round-ended bristle and coarse-cut bristle--in the first session and switched to another type in the second session. Gingival ulcers and plaque scores (dye technique) were recorded before and after brushing in each session. Abrasion of the bristles was examined by connecting a microscope with a microcomputer. It was found that both types of bristle ends were able to remove dental plaque significantly (p<0.05) and not different in their cleansing efficiency. The new round-ended bristle caused less ulcers than the new coarse-cut bristle toothbrushes (p<0.05). No statistical difference in gingival ulceration was found after the 40-day usage of these two types of bristles. Microscopically, the abrasion of sharp edges was found in both bristle types but there was no difference in appearance found among bristles of the same type that caused ulcers and no ulcer.

The salivary buffer capacity can be determined by several methods but they require so many laboratory equipments that they are incapable to be performed as a routine test of a field study. The objective of this research is to create a simplified kit for salivary buffer capacity determination that needs no laboratory equipment. The kit was prepared under the principle of titration by using the Whatman No.1 filter paper cut into 0.5 cm. diameter circular piece by the paper punch. A piece of paper was dipped into 0.3 M hydrochloric acid and put one by one into 1 ml of saliva until the color of methyl orange indicator changed from red to yellow. The result showed that the titration by the acid-dipped paper was similar to the standard titration by acid-dropping with no statistical difference at 95% confidence limit. The simple correlation analysis demonstrated that the numbers of acid-dipped paper directly related with the volume of acid used for titration (r=0.89). Both titration methods showed the same direction of buffer capacity level classified with the contingency coefficient = 0.78. Furthermore, the sensitivity of acid-dipped titration to categorize the level of buffer capacity into low, intermediate and high was as high as 90%. It was concluded that the acid-dipped paper was a simplified kit which had the efficiency as same as the standard titration and probably be a practical method for estimation of the salivary buffer capacity in the field study.The salivary buffer capacity can be determined by several methods but they require so many laboratory equipments that they are incapable to be performed as a routine test of a field study. The objective of this research is to create a simplified kit for salivary buffer capacity determination that needs no laboratory equipment. The kit was prepared under the principle of titration by using the Whatman No.1 filter paper cut into 0.5 cm. diameter circular piece by the paper punch. A piece of paper was dipped into 0.3 M hydrochloric acid and put one by one into 1 ml of saliva until the color of methyl orange indicator changed from red to yellow. The result showed that the titration by the acid-dipped paper was similar to the standard titration by acid-dropping with no statistical difference at 95% confidence limit. The simple correlation analysis demonstrated that the numbers of acid-dipped paper directly related with the volume of acid used for titration (r=0.89). Both titration methods showed the same direction of buffer capacity level classified with the contingency coefficient = 0.78. Furthermore, the sensitivity of acid-dipped titration to categorize the level of buffer capacity into low, intermediate and high was as high as 90%. It was concluded that the acid-dipped paper was a simplified kit which had the efficiency as same as the standard titration and probably be a practical method for estimation of the salivary buffer capacity in the field study.

The objective of this article was to explain cracked tooth syndrome which is more prevalent in middle age patients and the tooth most frequently affected is mandibular second molar. Predominantly, cracked tooth syndrome is the result of a masticatory tooth syndrome, many devices and techniques may be used as diagnostic aids in testing teeth suspected of cracks. In addition, this article also includes treatment, prognosis for dentists in order to make proper diagnosis and to give the treatment for cracked tooth syndromeThe objective of this article was to explain cracked tooth syndrome which is more prevalent in middle age patients and the tooth most frequently affected is mandibular second molar. Predominantly, cracked tooth syndrome is the result of a masticatory tooth syndrome, many devices and techniques may be used as diagnostic aids in testing teeth suspected of cracks. In addition, this article also includes treatment, prognosis for dentists in order to make proper diagnosis and to give the treatment for cracked tooth syndrome

The purpose of this study was to evaluate dental attitude in patients who did and did not experience Papoose Board restraints. Sixty children, 5-10 years old, who had the dental treatments at Pedodontic clinic, Mahidol University participated in this study. Thirty children had experiences with the use of Papoose Board and the others had not. The children dental fear were assessed by using the Children Dental Fear Picture Test developed by Klingberg. The questionnaire of the parents contained Corah Dental Anxiety Scale, sociodemographic data of children and parents, children medical history, children behavior, behavior of the families, and children memories of using Papoose Board. The results showed that there were statistically significant differences in the mean age at time of first dental treatment and the mean number of appointment visit (p<0.05). There were no differences in dental attitudes between the two groups. Both groups of children had positive attitudes toward dental treatment. No difference in dental attitudes appeared among the group of children who remembered the use of Papoose Board and who did not. In conclusion, when used properly, the use of Papoose Board for behavior management in children, does not affect dental attitudes in the future.

In Thailand, systematic information on oral health status is scarce. The present study was undertaken in order to describe the oral health status of schoolchildren of grade 1 (6 years) and grade 6 (12 years) in the province of Suratthani, Southern Thailand. Urban and rural schools were chosen at random from 19 districts of the province. The total sample comprised 1,154 children from grade 1 and 1,114 children from grade 6, and the participation rate was 99%. Clinical data were collected in 1996 according to the criteria of WHO, including dental caries and CPI. In grade 1 children, 96.4% were affected by dental caries in the primary teeth and the mean dmft was 8.1 (±4.3). At grade 6, the caries prevalence rate was 69.8% and the mean DMFT was observed at 2.4 (±2.6). At both grades and in both dentitions, untreated dental caries constituted most of the caries index. Only minor differences in dental caries were found according to sex and urbanization. The gingival conditions were poor, e.g. 89.6% of the children at grade 6 had CPI scores 1+2 (gingival bleeding or calculus). In conclusion, dental caries and gingival disease are the major oral health problems among children in Suratthani province.In Thailand, systematic information on oral health status is scarce. The present study was undertaken in order to describe the oral health status of schoolchildren of grade 1 (6 years) and grade 6 (12 years) in the province of Suratthani, Southern Thailand. Urban and rural schools were chosen at random from 19 districts of the province. The total sample comprised 1,154 children from grade 1 and 1,114 children from grade 6, and the participation rate was 99%. Clinical data were collected in 1996 according to the criteria of WHO, including dental caries and CPI. In grade 1 children, 96.4% were affected by dental caries in the primary teeth and the mean dmft was 8.1 (±4.3). At grade 6, the caries prevalence rate was 69.8% and the mean DMFT was observed at 2.4 (±2.6). At both grades and in both dentitions, untreated dental caries constituted most of the caries index. Only minor differences in dental caries were found according to sex and urbanization. The gingival conditions were poor, e.g. 89.6% of the children at grade 6 had CPI scores 1+2 (gingival bleeding or calculus). In conclusion, dental caries and gingival disease are the major oral health problems among children in Suratthani province.

Few studies have been conducted to highlight the oral health behaviour of children in Thailand. The objective of the present survey was to describe and analyze self-care practices of grade 6 schoolchildren in Southern Thailand. 1,116 children were selected according to the WHO pathfinder procedure in the province of Suratthani, Southern Thailand, and 1,084 children (97%) participated in personal interviews. The structured interview included questions on tooth cleaning habits, means of cleaning the teeth, and socio-cultural backgrounds of the children. In total, 78% of the children brushed their teeth two or mare times a day: girls more often (89%) than boys (67%) p<0.01). Use of fluoride toothpaste was claimed by 89%. Moreover, other means of tooth cleaning were mentioned, e.g. use of wooden toothpicks (45%) and chewstick/miswak (19%). Tooth brushing habits were associated with religion and level of education of the mothers (p<0.01). In conclusion, planning of oral health education for schoolchildren in Thailand should give emphasis to important socio-cultural subgroups.Few studies have been conducted to highlight the oral health behaviour of children in Thailand. The objective of the present survey was to describe and analyze self-care practices of grade 6 schoolchildren in Southern Thailand. 1,116 children were selected according to the WHO pathfinder procedure in the province of Suratthani, Southern Thailand, and 1,084 children (97%) participated in personal interviews. The structured interview included questions on tooth cleaning habits, means of cleaning the teeth, and socio-cultural backgrounds of the children. In total, 78% of the children brushed their teeth two or mare times a day: girls more often (89%) than boys (67%) p<0.01). Use of fluoride toothpaste was claimed by 89%. Moreover, other means of tooth cleaning were mentioned, e.g. use of wooden toothpicks (45%) and chewstick/miswak (19%). Tooth brushing habits were associated with religion and level of education of the mothers (p<0.01). In conclusion, planning of oral health education for schoolchildren in Thailand should give emphasis to important socio-cultural subgroups.

The objectives of this study were to assess the concurrence of torus palatinus and torus mandibularis, and the age and sex variations of the concurrence of both tori in a group of Thai population. The connection of the occurrence of both tori was also investigated. One thousand and two hundred subjects were clinically examined for the occurrence of torus palatinus and torus mandibularis at the Faculty of Dentistry, Chulalongkorn University. The subjects were equally divided into six age groups: 13-19, 20-29, 30-39, 40-49, 50-59, and 60 year and over. Each age group comprised of equal number of males and females. The Chi-square test used to analyze for group differences at p<0.05. The result showed that 22.9% of total subjects exhibited the concurrence of torus palatinus and torus mandibularis. There was a significant association between the concurrence of both tori with age (p=0.001). The concurrence of both tori was not significantly different between males and females (21.3% versus 24.5%, p=0.192). There was a relation between the occurrence of torus palatinus and torus mandibularis in total subjects, in males and in females (p<0.001). Our study showed that the concurrence of torus palatinus and torus mandibularis in a group of Thai population was rather high and the concurrence of both tori was significantly diferent with age. The relationship between the occurrence of TP and TM existed.The objectives of this study were to assess the concurrence of torus palatinus and torus mandibularis, and the age and sex variations of the concurrence of both tori in a group of Thai population. The connection of the occurrence of both tori was also investigated. One thousand and two hundred subjects were clinically examined for the occurrence of torus palatinus and torus mandibularis at the Faculty of Dentistry, Chulalongkorn University. The subjects were equally divided into six age groups: 13-19, 20-29, 30-39, 40-49, 50-59, and 60 year and over. Each age group comprised of equal number of males and females. The Chi-square test used to analyze for group differences at p<0.05. The result showed that 22.9% of total subjects exhibited the concurrence of torus palatinus and torus mandibularis. There was a significant association between the concurrence of both tori with age (p=0.001). The concurrence of both tori was not significantly different between males and females (21.3% versus 24.5%, p=0.192). There was a relation between the occurrence of torus palatinus and torus mandibularis in total subjects, in males and in females (p<0.001). Our study showed that the concurrence of torus palatinus and torus mandibularis in a group of Thai population was rather high and the concurrence of both tori was significantly diferent with age. The relationship between the occurrence of TP and TM existed.

A survey of 1790 Bangkok Metropolitan Schoolchildren, 9-15 years of age, in Bangkhaen district was conducted in order to determine the prevalence of dens Evaginatus and the associated pupal and periapical complications. The prevalence of this abnormally was found to be 1.79 per cent. The male to female ratio was 1.91. From this study the lower premolars showed 12.79 times more evaginations than the upper premolars. Evaginated teeth generally occurred symmetrically. Approximately seventy eight per cent of the affected premolars showed intact tubercles and the other 21.74 percent were either worn of fractured. Pulpal involvement was observed in 11.59 per cent of fractured tubecles whick failed to respond to the electric pulp test. Only 2.90 per cent of evaginated teeth showed radiographic evidence of periapical involvement.A survey of 1790 Bangkok Metropolitan Schoolchildren, 9-15 years of age, in Bangkhaen district was conducted in order to determine the prevalence of dens Evaginatus and the associated pupal and periapical complications. The prevalence of this abnormally was found to be 1.79 per cent. The male to female ratio was 1.91. From this study the lower premolars showed 12.79 times more evaginations than the upper premolars. Evaginated teeth generally occurred symmetrically. Approximately seventy eight per cent of the affected premolars showed intact tubercles and the other 21.74 percent were either worn of fractured. Pulpal involvement was observed in 11.59 per cent of fractured tubecles whick failed to respond to the electric pulp test. Only 2.90 per cent of evaginated teeth showed radiographic evidence of periapical involvement.

The objective of this study was to improve the physical properties of Zinc Oxide Eugenal Cement in accordance with ISO 3107:1988 (E) type 3 class 1 which can be used as a temporary filling material. Test specimens were prepared from propionic acid conditioning zinc oxide BP and polymethyl methacrylate mixed with oil of clove or eugenal oil and concentrate acetic acid. Fourteen specimens were prepared and tested according to ISO 3107:1988 (E). Five specimens were tested for compressive strength by Instron Corporation Series IV Automated Material Testing System 7.43.00. The setting time was measured at 37゜c, while disintegration of 4 specimens were measured after 24 h. The cement fulfils the performance required by ISO 3107:1988 (E) type 3 class 1 for temporary filling materials and bases.The objective of this study was to improve the physical properties of Zinc Oxide Eugenal Cement in accordance with ISO 3107:1988 (E) type 3 class 1 which can be used as a temporary filling material. Test specimens were prepared from propionic acid conditioning zinc oxide BP and polymethyl methacrylate mixed with oil of clove or eugenal oil and concentrate acetic acid. Fourteen specimens were prepared and tested according to ISO 3107:1988 (E). Five specimens were tested for compressive strength by Instron Corporation Series IV Automated Material Testing System 7.43.00. The setting time was measured at 37゜c, while disintegration of 4 specimens were measured after 24 h. The cement fulfils the performance required by ISO 3107:1988 (E) type 3 class 1 for temporary filling materials and bases.

The purpose of this study was to compare the resistance to vertical root fracture of two resin cements (Superbond and 3M Rely X ARC) and to observe the penetration of cement into the fracture surface. Thirty extracted human upper central incisors having approximately the same dentin thickness were used. The roots were sectioned from the crown to the length of 11.0 mm, and were endodontically prepared and filled with gutta-percha. The post spaces were prepared for cast metal posts. The roots with simulated periodontal ligament were embeded in the vilmix block. the specimens were mounted in an universal testing machine and loaded in compression until the root fractured. The fracture force was recorded in kiloNewton (kN). The fractured roots were randomly divided into 2 groups (n=15). The posts were reinserted and bonded with Superbond and 3M RelyX ARC, respectively. The bonded specimens were kept in 100% humidity for 24 hours, then were re-fractured and the force were recorded as re-fracture force. The mean fracture force was significantly higher than the mean re-fracture force (p<0.05). No significant difference between the re-fracture force after bonding with the two resin cements (p>0.05). Both resin cements can not completely penetrate into fracture line.The purpose of this study was to compare the resistance to vertical root fracture of two resin cements (Superbond and 3M Rely X ARC) and to observe the penetration of cement into the fracture surface. Thirty extracted human upper central incisors having approximately the same dentin thickness were used. The roots were sectioned from the crown to the length of 11.0 mm, and were endodontically prepared and filled with gutta-percha. The post spaces were prepared for cast metal posts. The roots with simulated periodontal ligament were embeded in the vilmix block. the specimens were mounted in an universal testing machine and loaded in compression until the root fractured. The fracture force was recorded in kiloNewton (kN). The fractured roots were randomly divided into 2 groups (n=15). The posts were reinserted and bonded with Superbond and 3M RelyX ARC, respectively. The bonded specimens were kept in 100% humidity for 24 hours, then were re-fractured and the force were recorded as re-fracture force. The mean fracture force was significantly higher than the mean re-fracture force (p<0.05). No significant difference between the re-fracture force after bonding with the two resin cements (p>0.05). Both resin cements can not completely penetrate into fracture line.

The objective of this study was to investigate the root trunk length and furcation entrance width in permanent molars. The study samples consisted of 100 first and 100 second maxillary molars, and 100 first and 100 second mandibular molars. The photographs of root trunks and furcation entrances were taken by the digital camera, and were measured by a computer-assisted image analysis system. The difference between the root trunk length and furcation entrance width of first and second molars was examined using Z-test. The results showed that the mean values of buccal, mesial and distal root trunk lengths of the maxillary first molars were 4.27±0.85, 4.23±0.81, and 4.60±0.93 mm, respectively, in the maxillary second molars the mean lengths of the buccal, mesial and distal root trunk length were 4.22±0.93 mm, respectively, in the maxillary second molars the mean lengths of the buccal and lingual root trunk lengths in mandibular first molars were 3.22±0.62 and 4.25±0.62 mm, while those of mondibular second molars were 3.35±0.62 and 4.30±0.37 mm. The mean values of buccal, mesial and distal furcation entrance widths in maxillary first molars were 0.78±0.32, 1.15±0.39, and 1.02±0.43 mm, while those of maxillay second molars were 0.74±0.27, 1.13±0.38, and 1.02±0.33 mm, respectively. Also, the mean values of buccal and lingual furcation entrance widths in mandibular first molars were, 1.11±0.31 and 1.33±0.37 mm, while those of mandibular second molars were 0.84±0.29 and 0.96±0.37 mm. The results indicated that the mesial root trunk length of maxillary second molars was significant by longer than that of the maxillary first molar (p<0.05). For the furcation entrance width, the buccal furcation entrance of maxillary first and second molars appeared to be narrower than that of the mesial and the distal furcation entrances. In addition, the buccal furcation entrance of mandubular molar was apparently narrower than of the lingual furcation entrance (p<0.005).The objective of this study was to investigate the root trunk length and furcation entrance width in permanent molars. The study samples consisted of 100 first and 100 second maxillary molars, and 100 first and 100 second mandibular molars. The photographs of root trunks and furcation entrances were taken by the digital camera, and were measured by a computer-assisted image analysis system. The difference between the root trunk length and furcation entrance width of first and second molars was examined using Z-test. The results showed that the mean values of buccal, mesial and distal root trunk lengths of the maxillary first molars were 4.27±0.85, 4.23±0.81, and 4.60±0.93 mm, respectively, in the maxillary second molars the mean lengths of the buccal, mesial and distal root trunk length were 4.22±0.93 mm, respectively, in the maxillary second molars the mean lengths of the buccal and lingual root trunk lengths in mandibular first molars were 3.22±0.62 and 4.25±0.62 mm, while those of mondibular second molars were 3.35±0.62 and 4.30±0.37 mm. The mean values of buccal, mesial and distal furcation entrance widths in maxillary first molars were 0.78±0.32, 1.15±0.39, and 1.02±0.43 mm, while those of maxillay second molars were 0.74±0.27, 1.13±0.38, and 1.02±0.33 mm, respectively. Also, the mean values of buccal and lingual furcation entrance widths in mandibular first molars were, 1.11±0.31 and 1.33±0.37 mm, while those of mandibular second molars were 0.84±0.29 and 0.96±0.37 mm. The results indicated that the mesial root trunk length of maxillary second molars was significant by longer than that of the maxillary first molar (p<0.05). For the furcation entrance width, the buccal furcation entrance of maxillary first and second molars appeared to be narrower than that of the mesial and the distal furcation entrances. In addition, the buccal furcation entrance of mandubular molar was apparently narrower than of the lingual furcation entrance (p<0.005).

The aims of this study were to compare the minimum inhibitory concentration level of tetracycline hydrochloride (TC) in gingival crevicular fluid (GCF) after single pocket irrigation with 5% and 10% concentrations at different time intervals. The subjects were systemic tetracycline within the past 6 months. The studied sites were the tooth surfaces having pockets 5-7 millimeters (the mean pocket depth is 5.11 millimeters). Two hundreds sites were divided into two groups: one group using 5% and another 10% TC (w/v, 15 ml, 5 min/site). The GCF samples were collected on paper strips at the time intervals, 1 hour, 1, 3, 5 and 7 days after pocket irrigation. The TC in each strip was eluted and analysed by high performance liquid chromatography. The results showed that the ratained TC concentration in GCF from both groups were not statistically different at 1 hour, level (MIC=8 µg/ml) up to 5 days (p<0.05). At 7 days after pocket irrigation, the TC concentrations in GCF was significantly higher (p<0.05) in the 10% TC group (10.13 ±1.77 µg/ml) than in the 5% TC group (5.41±0.84 µg/ml).The aims of this study were to compare the minimum inhibitory concentration level of tetracycline hydrochloride (TC) in gingival crevicular fluid (GCF) after single pocket irrigation with 5% and 10% concentrations at different time intervals. The subjects were systemic tetracycline within the past 6 months. The studied sites were the tooth surfaces having pockets 5-7 millimeters (the mean pocket depth is 5.11 millimeters). Two hundreds sites were divided into two groups: one group using 5% and another 10% TC (w/v, 15 ml, 5 min/site). The GCF samples were collected on paper strips at the time intervals, 1 hour, 1, 3, 5 and 7 days after pocket irrigation. The TC in each strip was eluted and analysed by high performance liquid chromatography. The results showed that the ratained TC concentration in GCF from both groups were not statistically different at 1 hour, level (MIC=8 µg/ml) up to 5 days (p<0.05). At 7 days after pocket irrigation, the TC concentrations in GCF was significantly higher (p<0.05) in the 10% TC group (10.13 ±1.77 µg/ml) than in the 5% TC group (5.41±0.84 µg/ml).

The objectives of this study were to investigate the relationship between the occurrence of torus palatinus with palatal arch dimensions and maxillary arch forms in Thai subjects. The study included 366 Thais with equal number of men and women. Subjects who had no torus palatinus showed significantly deeper palates than subjects who had torus palatinus (p<0.001). The palatal arch length and width did not differ in both groups. There were no association between the size of torus palatinus and palatal arch dimensions. Torus palatini were found more common on the maxillary arches with parallel (75.9%) and divergent ends (75.1%) than those with convergent ends (63.3%). However, these differences were not statistically significant. Our finding supported the previous study in that an association between the occurrence of torus palatinus and palatal arch height existed, but the relationship between the occurrence of torus palatinus and maxillary arch forms was not demonstrated.The objectives of this study were to investigate the relationship between the occurrence of torus palatinus with palatal arch dimensions and maxillary arch forms in Thai subjects. The study included 366 Thais with equal number of men and women. Subjects who had no torus palatinus showed significantly deeper palates than subjects who had torus palatinus (p<0.001). The palatal arch length and width did not differ in both groups. There were no association between the size of torus palatinus and palatal arch dimensions. Torus palatini were found more common on the maxillary arches with parallel (75.9%) and divergent ends (75.1%) than those with convergent ends (63.3%). However, these differences were not statistically significant. Our finding supported the previous study in that an association between the occurrence of torus palatinus and palatal arch height existed, but the relationship between the occurrence of torus palatinus and maxillary arch forms was not demonstrated.

The purpose of this study was to evaluate the effect of time, storage temperature and type of solution to the stability of Haiter. Iodometric titration method was used to determine the amount of available chlorine which indicated the stability of Haiter. Both types of Haiter, regular type and perfumed type, at 6% and 3% concentration which stored in air-conditioned and room temperature were studied. Samples were stored in tightly covered amber glass bottles at room temperature and measurement of available chlorine was done at week 0, 2, 4, 8 and 12. Results showed that the effect of time to the stability of Haiter was significantly different at the second week of the study (p<0.05). Storage temperatures and types of solution had no effect to the stability of Haiter.The purpose of this study was to evaluate the effect of time, storage temperature and type of solution to the stability of Haiter. Iodometric titration method was used to determine the amount of available chlorine which indicated the stability of Haiter. Both types of Haiter, regular type and perfumed type, at 6% and 3% concentration which stored in air-conditioned and room temperature were studied. Samples were stored in tightly covered amber glass bottles at room temperature and measurement of available chlorine was done at week 0, 2, 4, 8 and 12. Results showed that the effect of time to the stability of Haiter was significantly different at the second week of the study (p<0.05). Storage temperatures and types of solution had no effect to the stability of Haiter.

Dentine hypersensitivity is a long-standing problem in dentistry. The dentine exposure can occur by loss of enamel of by gingival recession. The current treatments tend to be temporary in their effect. Recent advances in biology of dentine and pulp offer a better understanding of the mechanism of action, etiological factors of dentine hypersensitivity and role of inflammatory reaction in development of dentine hypersensitivity. The new and more effective modes of management are also suggested to use for the future.

Ulceration due to cytomegalovirus (CMV) infection rarely occurs in the oral cavity. The aim of this report was to document a case of CMV oral ulcer. The Thai female patient was present with pain at the left retromolar area. The patient was HIV-positive. Oral examination revealed an ulcer at the left retromolar mucosa. Histopathologically, the specimen showed characteristic features of CMV infection; enlarged endothelial cells with intranuclear and intracytoplasmic inclusion bodies. Because of her economic status, the supportive treatment was provided to alleviate the pain.Ulceration due to cytomegalovirus (CMV) infection rarely occurs in the oral cavity. The aim of this report was to document a case of CMV oral ulcer. The Thai female patient was present with pain at the left retromolar area. The patient was HIV-positive. Oral examination revealed an ulcer at the left retromolar mucosa. Histopathologically, the specimen showed characteristic features of CMV infection; enlarged endothelial cells with intranuclear and intracytoplasmic inclusion bodies. Because of her economic status, the supportive treatment was provided to alleviate the pain.