Teething is the process by which an infant’s first tooth sequentially appears by emerging through the gums. It is a natural process that generally causes some discomfort and requiring no medical intervention. Tongue biting during sleeping caused by teething is a rare condition. However, in unusually severe cases, it can result in extensive and painful ulceration causing considerable distress for both the child and his/her parents. The ulceration not only induces pain but also interferes feeding and sleeping. Herein we report a case of extensive ulceration due to tongue biting in a one year and three month-old boy who was successfully treated with the modified custom–made mouthguard. To construct the appliance in one visit appointment and apply it in a young infant, we chose the alginate fast-set impression and stock tray commonly used in a dental unit. The appliance was made from soft, thick vinyl. The denture fixation cream was also employed during the procedure. This mouthguard was used only during nighttime to protect the tongue and facilitate healing. The treatment outcome indicated significant improvement within the first week after the intervention. Once the teeth pop up and the ulcerations disappear, the mouthguard is no longer needed. This technique may be applied to other relatively similar conditions affecting young children.

The aim of this study was to develop an orthodontic screening guideline for different dentition stages using Delphi technique. A questionnaire regarding the appropriateness of orthodontic treatment for different problems in various dentition stages were sent to 23 orthodontic experts throughout Thailand for several rounds. The level of agreements from the previous round were analyzed and presented in the subsequent round. The procedure was repeated until the agreement of each item reached 55% or more. According to the experts, the conditions that should be treated in primary dentition were early loss of posterior primary tooth/teeth, complete overbite causing palatal trauma, functional shift from occlusal interference and non-nutritive sucking. Early mixed dentition was an appropriate stage to treat all types of malocclusion except for anterior crowding and median diastema which should be postponed to a later stage. Lastly, except for gummy smile, all problems should be treated in late mixed and permanent dentition. Patient’s perceived need and cooperation were important additional treatment timing considerations. In conclusion, Thai orthodontic experts agreed that treatment should not be performed in primary dentition except for conditions that may cause injuries or increase the severity of the malocclusion. In early mixed dentition, treatment of conditions that may not increase the severity of the malocclusion could be postponed to the late mixed dentition stage. Further studies should be focused on the application of the guideline.

The objective of this study was to analyze caries-related factors in patients undergoing orthodontic treatment with fixed appliances by using the Cariogram computer program. Materials and Methods were thirty orthodontic patients, aged 12-26 years, were participated in this study. Caries related-factors were investigated before treatment, 1 and 3 months after appliance placement. Interview, caries examination and plaque score were performed. A paraffin-stimulated whole saliva sample was collected for measurements of salivary flow rate, buffer capacity, mutans streptococci and lactobacilli levels. All data were ranked and entered into the software to show the chance of avoiding caries as a percentage. According to the Cariogram, the patients were divided into two groups based on their chance of avoiding new caries (>60.0% or ≤ 60.0%). In the low risk group, the mean value of Cariogram percent significantly decreased from 77.8% to 64.0% after bonding with fixed appliances for 3 months (p < .01). In the high risk group, there was a significant increase of the plaque index 3 months after wearing fixed appliances (p < .01). In conclusion, the caries risk profiles of the patients with fixed orthodontic appliances can be assessed periodically by using the Cariogram software.

The objective of this study was to assess the effect of light curing direction on shear bond strength and degree of cure of a light-cured orthodontic adhesive. Seventy-two extracted human premolar teeth, 12 teeth in each group, were bonded to stainless steel brackets with a light-cured adhesive, cured by light in 3 different directions; 1) mesial & distal direction 2) buccal direction and 3) occlusal direction. The samples were tested for shear bond strength by a universal testing machine at 5 minutes and 24 hours after light activation. In degree of cure study, the teeth were bonded to stainless steel brackets with a light-cured adhesive, by curing with 3 different lights as mentioned in shear bond strength study. The adhesive was tested for degree of cure by Fourier transform infrared spectroscopy 5 samples repeatedly at 5 minutes and 24 hours after light activation. Results showed that shear bond strengths of all light direction testing groups were not significantly different in both 5 minutes and 24 hours after bonding. Degree of cures of a light-cured adhesive, cured by light in mesial & distal direction, were significantly higher than those cured by buccal direction. However the degree of cures of a light-cured adhesive, cured by light in occlusal direction were not significantly different from those two groups. In conclusion, light curing direction has an effect on degree of cure of a light-cured orthodontic adhesive but it has no effect on shear bond strength.

Hypoxia is known to have two faces in the same coin. On one side, a hypoxic condition plays an important role in the pathogenesis of many diseases and makes them more progressive. On the other hand, hypoxia turns to be the suitable microenvironment for stem cells, known as "stem cell niche", and becomes the attractions in the field of stem cells research. This literature provides the basic knowledge on a mechanism of hypoxic sensing at a cellular level. Then, the role of hypoxia on behaviors of different kinds of stem cells, especially dental stem cells is highlighted. In addition, the hypoxic signaling pathway among stem cells is discussed. This knowledge could help researcher find an optimal condition for stem cell culture and apply it in the future clinical uses.

Dental caries is occurred due to an imbalance between demineralization and remineralization. The mineral loss has resulted from acids produced by bacteria in biofilms. Several studies showed that mutans streptococci are predominant bacteria playing in this important role. Therefore, removal of these bacteria is one of the caries prevention strategies. Current antimicrobial agents have broad-spectrum activity. They are effective against wide-range of bacteria leading to opportunistic infections. This fact prompts an interest in searching a new approach that selectively eliminates cariogenic bacteria. Peptidoglycan hydrolase is an enzyme that degrades peptidoglycan, the major component of the cell wall of gram positive bacteria. With potential to eliminate bacteria including antibiotic resistant strains, the enzymes have been studied by several research groups. Automutanolysin is a peptidoglycan hydrolase produced by Streptococcus mutans. The enzyme has been interesting because it shows substrate specificity against mutans streptococci. Moreover, the previous study showed that the enzyme has ability to lyse clinical isolations in biofilm form. All data together indicates the possibility in developing automutanolysin as an alternative approach in caries prevention.

The aim of this prospective comparative study was to evaluate the peri-implant parameter (plaque index, bleeding index, gingival index, probing depth and keratinized mucosa), marginal bone level, implant stability and complication after implant placement. Sixty-three patients participated in this study. After randomization, 32 patients underwent with two-stage procedure (control group) and 31 patients underwent with single stage procedure (test group). Two implants were placed (3.7x13 mm.) at lower canine region and follow up at 0, 18, 22 and 26 weeks after implant placement. The survival rate was 98.44% for the control group and 98.39 for the test group. There was no statistical differences in peri-implant parameter, marginal bone level and implant stability (p > .05) between both groups. This study demonstrated that both single and two-stage procedures were equally successful. However, the single stage procedure was more favorable for less time consumed, more cost effectiveness and reduced risk of the second stage surgery complications.

The aim of this study was to evaluate the reliability and construct validity of the Thai version of denture complaint questionnaire for measuring satisfaction of complete denture patients. Forty complaints of the original English version proposed by Vervoorn et al. were translated into Thai. Fifty thousand lists of sampling frame were patients, age 60 years and over, treated with complete dentures in Dental Prostheses Campaign to celebrate the King’s 80th Birthday Anniversary. A random sample of size 2,704 was selected by means of multistage sampling designs with 21 primary sampling units of provinces from 76 provinces overall country, within each of provinces, selecting 1-4 secondary sampling units of hospitals, and at the last stage, within each hospital, selection of 30-40 patients available with proportional to population size. Reliability was evaluated using Cronbach’s alpha coefficient. Construct validity was assessed by using both exploratory and confirmatory factor analysis. Results showed that reliability of the 40-item questionnaire was high (0.88). Construct validity analysis yielded the shortened Thai version of 19-item denture complaint questionnaire which contained 5 components and had 0.86 as its value of reliability. This construct validity of 19-item denture complaint questionnaire containing 5 components was confirmed by model construction using all samples. Half the sample was randomly selected to use in a model reconfirmation in order to reassure that this questionnaire can be used in other studies. In conclusion, the Thai version of 19-item denture complaint questionnaire is a valid and reliable instrument to measure satisfaction of complete denture among Thai patients.

The objectives of this study were to evaluate the quantity of bone after grafting in cleft patients and to investigate factors influencing success of the secondary bone grafting. The sample comprised 100 cleft patients (56 male, 44 female) of the Craniofacial Anomaly Clinic at Dental Hospital Chulalongkorn University with a mean age of 14.45±5.62 years (8.7-32.5 years). There were 62 unilateral cleft lip and palate, 21 bilateral cleft lip and palate, and 11 unilateral alveolar cleft patients. The autologous bone grafting with cancellous bone from iliac crest was prescribed to each patient. Occlusal topographic radiographs immediately before bone grafting and 3-6 months after bone grafting were used to evaluate the result of bone grafting. The amount of bone after grafting was classified into 4 levels: level 1 (≥ 75.0%), level 2 (≥ 50.0%), level 3 (≥ 25.0%), and level 4 (< 25.0%), respectively. The associations between factors influencing bone grafting and the availability of bone after grafting were analyzed by Chi-square test at 95% confidence interval. The results showed that in 127 alveolar cleft sites, the success rate was 94.5% among them, 78.0% was level 1, 16.5% was level 2, and the remaining 5.5% was level 3. Patient’s age and the stage of canine eruption had significant relationship with the success of alveolar bone grafting (p < .05). The results supported the previous studies that the appropriate timing for bone grafting is before the eruption of the canine adjacent to the cleft side.

The growth of the elderly population has affected the health care system due to their physical and oral tissue changes, together with a high prevalence of chronic diseases, relate to the quality of life in the elderly. The objective of this study was to analyze the characteristics and trends of elderly patients receiving dental care at the Faculty of Dentistry, Chulalongkorn University, Bangkok Thailand. The information of newly registered elderly patients from year 2007 to 2009 was collected from 1,320 dental treatment records using a systematic random sampling method. To evaluate prosthodontic treatment trends, 634 dental treatment records were selected from newly registered elderly patients in the postgraduate prosthodontic clinic. For the subjects sampled from all newly registered elderly patients, the most common systemic conditions identified were hypertension, diabetes mellitus, heart disease, and high cholesterol. The most common oral complaint was tooth loss with inefficient chewing and/or needing a new prosthesis. We found 38.3% of the subjects had a perceived need for prosthodontic treatment, while 64.8% had normative prosthodontic treatment needs. This survey revealed that the average number of occluding natural pairs of teeth was 2.8. The most frequent prosthodontic treatment received by elderly patients in the postgraduate prosthodontic clinic was removable dentures (60.3%). The average waiting period for prosthodontic treatment was 134.1 days, and the average prosthodontic treatment period was 155.4 days. However, there was a continuous decrease in the duration of both waiting and treatment periods from 2007 to 2009.

The purposes of this study were to develop the optimal wax cube hardness for evaluating the chewing ability of totally edentulous patients wearing complete dentures and to find the suitable hardness for patients with chewing ability close to those of normal dentition. Three formulations of wax cubes, hard, original, and soft, were developed by mixing different ratios of bees wax and microcrystalline wax. The hardness’s of the three types of wax cubes and sixteen common foods were determined using a Universal Testing Machine (SHIMADZU®). Twenty patients with normal dentitions (mean age 27.85±1.42 years), twenty patients with complete dentures (mean age 70.55±9.14 years) and twenty patients with implant-retained lower complete dentures (mean age 67.70±6.68 years) were selected. Each subject chewed three wax cube pieces sequentially, of each hardness type, for 10 chewing strokes using habitual chewing patterns. The chewed wax images were captured and analyzed by the Image J program (NIH), which calculated the percentage of well-mixed color areas. Statistical analysis revealed a significant difference (p < .05) in percentage of chewing ability between the normal dentition group, the complete denture group, and the implant-retained lower complete denture group when chewing original and soft wax cubes. The complete denture group had an approximately 35 percent reduction in chewing percentage when chewing original and soft wax cubes compared to the normal dentition group. The implant-retained lower complete denture group showed a higher percentage of chewing ability than the complete denture group. We conclude that the best wax cube hardness for use in chewing ability evaluation of total edentulous patients with complete dentures are the original and soft wax cubes, which are in the same range as common food we tested. The hard wax cube hardness was difficult to chew, and beyond the food hardness range. Our results suggest that the two-colored wax cube is an option for screening chewing ability and should be accompanied by some nutritional assessment tools to evaluate nutritional status in the elderly patients.

The objective of this study was to investigate the effect of 4-META application on transverse strength of metal-reinforced denture base acrylic resin. 5% 4-META acetone solution, sandblasting and combination of both were treated on either 18 gauge stainless steel wire or brass mesh, and then embedded in acrylic resin specimen. Denture base acrylic resin without metal insert was prepared as a control group. Ten specimens for each of seven groups were in water storage at 37 oC for 48 hours. The specimens were tested by the universal testing machine using a three-point flexure test at a crosshead speed of 5 mm/min until fracture. The results indicated that stainless steel wire significantly enhanced the fracture resistance of acrylic resin (p < .05). However, no significant differences in transverse strength were found between groups of stainless steel wire with 5% 4-META acetone solution, sandblast, or sandblast plus 5% 4-META acetone solution application and group of stainless steel wire without surface application (p > .05). The brass mesh did not strengthen acrylic resin no matter if surface was treated with 5% 4-META acetone solution or not.

The purpose of this study was to compare the shear bond strength of different adhesive systems for bonding orthodontic brackets under non-contaminated and artificial saliva-contaminated conditions. One hundred and sixty maxillary first premolars were divided into eight groups of twenty. Stainless steel brackets were bonded using one of the following adhesive systems: conventional adhesive system (TransbondTM XT), or moisture-resistant adhesive systems (TransbondTM Plus Color Change, Beauty Ortho Bond® and Assure®) on both non-contaminated and artificial saliva-contaminated enamel. Shear bond strength was measured using an Instron® Universal Testing Machine. Analysis of variance and Tukey’s test were used to compare the differences in the mean values. The results show that the mean shear bond strength of TransbondTM XT under noncontaminated conditions (11.70±3.14 MPa) was significantly superior to that of the other systems, both under non-contaminated and artificial saliva-contaminated conditions (p < .05), whereas the mean shear bond strength of TransbondTM XT under artificial salivacontaminated conditions (7.24±1.86 MPa), TransbondTM Plus Color Change under noncontaminated and artificial saliva-contaminated conditions (7.37±1.59 and 6.44±1.40 MPa, respectively), Beauty Ortho Bond® under non-contaminated and artificial salivacontaminated conditions (6.28±2.05 and 6.66±2.01 MPa, respectively), and Assure® under non-contaminated and artificial saliva-contaminated conditions (6.74±1.61 and 7.28±1.06 MPa, respectively) were not significantly different. In conclusion, artificial saliva contamination significantly decreased the mean shear bond strength of TransbondTM XT, but did not affect the mean shear bond strength of the other systems. Nevertheless, the mean shear bond strength of all systems was greater than 6 MPa, which is clinically acceptable for bonding orthodontic brackets.

The objective of this present study was to compare percent of weight changing of enamel and calcium inos concentration in various solutions simulated oral conditions. Ninty six bovine enamel slabs were prepared and randomly divided into 4 groups of solutions: lactic acid (Group 1) artificial saliva (Group 2) lactic acid+artificial saliva (Group 3) and lactic acid+artificial saliva+hydroxyapatite crystal (Group 4). Each group was test in 5 hr, 24 hr, 72 hr, and 168 hr (n=6). At the end of each time, the sample solutions were diluted and analyzed for calcium ions concentration by inductively coupled plasma spectrometer. The specimens were cleaned and dried. The weight was measured and calculated to percent of weight changing. Statistically significant difference of percent of weight changing was found between groups in each time interval. Arrangement in order of percent weight loss was maximum in group 1, 3 and 4. Statistically significant difference in increasing weight of Group 2 was found in 168 hr. Calcium ions concentration were significant difference between groups in each time interval, except in 168 hr of Group 1 and 4 were no significant difference. Decreasingly in calcium ions concentration of Group 2 was significant difference in 168 hr. Increasingly in calcium ions concentration of Group 4 was no significant difference in all time intervals. The acidic condition caused weight loss of enamel. The degree of saturation in the solution reduced weight loss from acid demineralization.

The purpose of this study was to investigate the effect of organized learning experience on the values of total occlusal convergence (TOC) prepared on crown abutments by dental students. Standard specimens and teeth (abutment), No. #11 and #46, were prepared with five different TOCs: 0, 6, 12, 20, and 30 degrees. The subjects were fortyfour sixth year dental students who prepared the abutment teeth. Then the subjects learned the standard value and followed by preparing abutment teeth again. The recorded TOCs were analyzed for t-test and Chi-square at α = .05. The results showed that the TOCs of crown abutments #11 and #46 prepared by dental students decreased statistically with significant difference after organized learning experience (p > .05). Within the limitations of this study, the effect of the organized learning experience decreased the TOCs of crown abutments prepared by dental students into the appropriate clinical TOCs.

Work-related Musculoskeletal Disorders are the common problem among dentists because some dental treatment procedures require dentists to work in awkward positions. Furthermore because of restriction of oral cavity, dentists may need to stay in static posture including head, neck, back, hands, and feet for long time. A number of studies attempt to look for evidence causal relation between work related and musculoskeletal disorders. Although the causes of musculoskeletal disorders are multifactor, the major risk factors include inappropriate workplace, long working period, and too many patients within day and psychological stress. The objective of this review is to emphasize these occupational hazards to general dentists in order to improve their health and work environment. In addition, the prevalence and mechanism leading to musculoskeletal disorders in dentists, and prevention are also included.