JOURNAL OF THE DENTAL ASSOCIATION OF THAILAND

  • Issue 3 volume 74
  • Issue 2 volume 74
  • Issue 1 volume 74
1
Page : 146 - 155

Title : Microleakage of Class II Restoration Using Short Fiber-Reinforced Flowable Resin Composite with a Universal Adhesive

Author(s) : Parichat Panyawisitkul, Sirivimol Srisawasdi

Keyword(s) : Flowable resin composite,microleakage,short fiber-reinforced resin composite,thermocycling

Manuscript Type : Original Article (บทวิทยาการ)

Page : 146 - 155

With short-fiber reinforced resin composite (SFRC), improved mechanical strength and good workability could be achieved within a single material. However, there remains concerns related to microleakage, which could restrict the application of this material in certain clinical situations. Thus, the aim of the study is to investigate microleakage of class II cavities restored with SFRC compared to other resin composites, in a simulated aging environment using thermocycling. Class II cavities were prepared in 80 premolars at the cementoenamel junction. Each group, consisting of 10 specimens, was restored with different materials: bulk-fill flowable SFRC (EverX Flow), bulk-fill SFRC (EverX Posterior), flowable bulk-fill resin composite (Tetric N-flow), and conventional resin composite (Filtek Z350XT). The specimens were divided into two subgroups: one underwent thermocycling of 20,000 cycles, while the other did not. All specimens were subjected to the dye penetration test and then assessed for microleakage scores. In the non-thermocycling group, no significant differences in microleakage scores were observed. In the thermocycling group, EverX Posterior showed a significant difference in microleakage scores compared to Tetric N-flow (p = 0.018) and all other tested materials (all p < 0.001). However, there was no significant difference in microleakage scores between EverX Posterior and Filtek Z350XT (p = 0.714), or between Filtek Z350XT with Tetric N-flow (p = 0.951). In conclusion, when restored with a universal adhesive, bulk-fill flowable SFRC achieved the highest microleakage score compared to other tested resin composite after thermocycling. In addition, all materials showed a significantly higher microleakage score after thermocycling. The materials could be ranked in ascending order of susceptibility to microleakage after aging by bulk-fill SFRC, conventional resin composite, flowable bulk-fill resin composite, and bulk-fill flowable SFRC, respectively.

2
Page : 139 - 145

Title : The Effectiveness of Probiotic Milk Tablets in Preventing Dental Caries Among Young Children: A Cluster Randomized Control Trial- 12-Months Results

Author(s) : Prasit Wongsupa, Kittisak Tunkura, Rattanaporn Jantama

Keyword(s) : Dental caries prevention,Probiotic milk tablets,Young children

Manuscript Type : Original Article (บทวิทยาการ)

Page : 139 - 145

The research aimed to assess the effectiveness of probiotic milk tablets in preventing dental caries in children attending 12 selected kindergartens in Phayao Province, Thailand, from June 2022 to May 2023. The goal was to determine if probiotic-fortified milk tablets could serve as a viable method for preventing dental caries in children aged 2-5 years. Study participants needed to meet specific inclusion criteria, including being aged 2-5 years, attending one of the designated daycare centers, and having parental consent. Exclusion criteria encompassed conditions like cow’s milk allergy, serious medical issues such as heart disease or asthma, oral and jaw abnormalities, the inability to undergo oral health assessments, or developmental delays. The participants were divided into control and treatment groups, with the treatment group receiving three milk tablets daily. Both groups received oral hygiene guidance. The milk tablets contained the probiotic Lactobacillus rhamnosus SD11. Each participant underwent oral examinations conducted by the dentists at the beginning of the study and subsequently every four months for 12 months to detect the presence of caries. The minimum required number of study participants was calculated to be 208 based on the estimated caries prevalence in the study population. Initially, 260 participants (136 males) were enrolled in the study, with 130 in the control group and 130 in the intervention group. The mean numbers of caries per participant in the control group at 4, 8, and 12 months were 5.74, 5.78, and 7.34, respectively. In contrast, the mean numbers of caries in the intervention group at 4, 8, and 12 months were 3.56, 3.33, and 3.43, respectively. Statistical analysis indicated that the differences in the mean caries numbers between the control and intervention groups at 4, 8, and 12 months were statistically significant (p=0.019, p=0.018, and p=0.001, respectively). In summary, the intervention group showed significantly fewer caries cases compared to the control group. Consequently, this intervention be considered for the study group to reduce caries. However, further research is needed to determine if this intervention can be extended to other populations of children of similar age, different age groups and multi-center study.

3
Page : 131 - 138

Title : Root Canal Angulation Change When Using Reciprocating Files in Different Temperatures

Author(s) : Siripat Lertnantapanya, Somsinee Pimkhaokham

Keyword(s) : Blue wire,Gold wire,M wire,Root canal angulation reduction,Temperature

Manuscript Type : Original Article (บทวิทยาการ)

Page : 131 - 138

Heat-treated NiTi files express different properties at body temperature depending on the type of heat treatment. The aim of this study was to evaluate the reduction of root canal angulation using Blue, Gold and M wire
NiTi file systems at different temperatures in simulated severely curved root canals. Eighty-eight resin models with 45° curved root canals were divided into eight groups based on temperature during instrumentation and file type: WaveOne Gold primary file (WOG), WaveOne primary file (WO), Reciproc Blue file (RPB), and Reciproc file (RP) at room temperature (25°C), with four additional groups at intracanal temperature (35°C). Resin models and handpieces were mounted on a customized fixed stand with restricted vertical handpiece movement in a temperature-controlled incubator. The sample preparations were conducted consistently in terms of cycle and amplitude by one operator. Curvature angulation of the canal was analyzed by using ImageJ according to Schneider's method. Mean differences in curvature degrees before and after instrumentation were compared within each group. The results showed that both temperature and file type affected the reduction in canal angulation (
p < 0.001). WOG and RPB showed the lowest mean angulation reduction, followed by RP and WO (p < 0.001). There was a significant difference between 25°C and 35°C instrumentation in the WO and RP groups (p < 0.001), but not in the WOG or RPB groups (P = 0.65, 0.17). In severely curved canals, reduction of canal angulation after preparation was influenced by file type especially with M-wire (WO, RP) and temperature (35°C) 

4
Page : 123 - 130

Title : Effect of Variations in Translucency of CAD/CAM Lithium-disilicate Ceramic and Abutment Color on Optical Color of Veneer Restoration

Author(s) : Wichaya Likitnuruk, Jeerapa Sripetchdanond, Sirivimol Srisawasdi

Keyword(s) : CAD/CAM block,Ceramic translucency,Ceramic veneers,Color difference,Lithium disilicate ceramic

Manuscript Type : Original Article (บทวิทยาการ)

Page : 123 - 130

This study aimed to evaluate color differences of different translucencies of CAD/CAM lithium-disilicate ceramics on backgrounds with different values. Low translucency (LT) and medium translucency (MT) rectangular-shaped specimens (0.6 mm thickness, shade A1) were fabricated from IPS e.max CAD (EMC; Ivoclar Vivadent) and Amber Mill (AM; HASS). Six specimens of EMC-MT, EMC-LT, AM-MT, and AM-LT were fabricated, resulting in 24 specimens in total. The specimens were placed on six background colors (1M1(reference), 1M2, 2M2, 3M2, 4M2, and 5M2) made of light-cured resin composite (Vita VM LC Base Dentine, Vita Zahnfabrik) using glycerine as a medium. The CIE L*a*b* coordinates were evaluated using a spectrophotometer (Ultrascan PRO, Hunter Lab) and calculated using the CIEDE2000 formula to determine the color difference (ΔE00) and translucency parameter (TP00) of the materials. Mean ΔE00 values were statistically analyzed using a two-way analysis of variance (ANOVA) and Bonferroni post-hoc tests (α=0.05), then qualitatively analyzed to consider the perceptibility threshold (PT) and acceptability threshold (AT). Mean TP00 values were analyzed by an independent t-test (α=0.05). The results revealed that the ΔE00 values significantly increased as darker backgrounds were used. The significantly higher ΔE00 values of MT compared to LT were presented when EMC specimens were placed on 2M2, 3M2, 4M2, and 5M2 backgrounds. The ΔE00 values below AT were found in the specimens placed on the 1M2 background. The TP00 values showed that MT had a statistically significant higher value compared to LT in both EMC and AM, and values from AM were higher than EMC. In conclusion, the masking ability of specimens was lower when placed on darker backgrounds. For the 2M2 darker background, IPS e.max CAD in low translucency showed better masking ability than medium translucency. Amber Mill showed more translucency and poorer masking properties than IPS e.max CAD.

5
Page : 108 - 122

Title : Invasive Maxillary Mucormycosis in Post-COVID-19: A Case Report and Review of Literatures

Author(s) : Boosana Kaboosaya, Napat Damrongsirirat, Saraporn Koosrivinij, Atiphan Pimkhaokham

Keyword(s) : COVID-19,Fungal infection,Jaws,Mucormycosis

Manuscript Type : Case Report

Page : 108 - 122

Patients with COVID-19 are predisposed to opportunistic fungal infections, particularly mucormycosis. This risk is heightened in individuals with specific systemic conditions, such as uncontrolled diabetes mellitus, immunocompromised status, or as a consequence of prescribed medications. Although mucormycosis typically presents acutely in the rhinocerebral region, originating from the upper turbinate and paranasal sinus, reported cases of mucormycosis in the jaws are scarce. This study presents a unique case involving a 60-year-old immunocompetent female with a history of COVID-19. Following discharge, she experienced mobility in the upper anterior teeth accompanied by pus discharge, leading to a diagnosis of maxillary mucormycosis upon histopathological investigation. Notably, the patient exhibited no prior immunocompromised status, emphasizing the need for heightened awareness even in immunocompetent individuals with a history of COVID-19. Globally, there has been an increase in fungal infections following the COVID-19 pandemic, with limited presentations. Prompt identification of maxillary mucormycosis post-SAR-CoV-2 infection is crucial for timely intervention. This study elucidates a case of COVID-19-associated mucormycosis (CAM) in an immunocompetent patient and reviews the existing medical literature on CAM affecting the jaw, thereby contributing to the understanding and management of this emerging issue.

1
Page : 55-61

Title : Assessing the Significance of Periodontal Inflamed Surface Area (PISA) in Determining Periodontitis Severity

Author(s) : Parina Changming, Kanoknadda Tavedhikul, Kajorn Kungsadalpipob, Sasivimol Rattanasiri, Prin Vathesatogkit, Lalitsara Thienpramuk, Attawood Lertpimonchai

Keyword(s) : Periodontal inflamed surface area (PISA),Periodontitis,Periodontal parameter

Manuscript Type : Original Article (บทวิทยาการ)

Page : 55-61

The Periodontal Inflamed Surface Area (PISA) is a novel parameter which quantifies the extent of periodontal inflammation. This cross-sectional study aimed to explore the association between the PISA value and conventional
parameters, including mean probing pocket depth (PPD) and mean clinical attachment level (CAL). Additionally, the PISA value was compared across severity levels of periodontitis, as classified by the CPITN and CDC/AAP definitions in the Electricity Generating Authority of Thailand (EGAT) workers. PISA was calculated using full-mouth periodontal parameters including PPD, CAL, and bleeding on probing. Periodontitis, as defined by CPITN and CDC/AAP, was classified into no/mild, moderate, or severe periodontitis. The reliability of PISA compared with severity types of periodontitis defining by CPITN and CDC/AAP was explored by the Kruskal-Wallis test. Among a total of 2,643 participants aged 34-74 years, the median of PISA value was 319.4 mm2 with a range of 2.2 to 3624.4 mm2, and the mean of PISA value was 440.68±415.40 mm2. When defining periodontitis according to CPITN and CDC/AAP, the prevalence of severe periodontitis were 28.7% and 26.3%, respectively. Pearson’s correlation indicated that the correlation between PISA and mean PPD, as well as between PISA and mean CAL, was significant (p <0.001) with coefficients of 0.78 and 0.52, respectively. When comparing PISA values across severity levels, there were statistically significant (p <0.001) differences in PISA values among severity levels of periodontitis classified by CPITN and CDC/AAP. A dose-response relationship was also observed. Therefore, periodontal parameter represented by PISA had the significant association with conventional periodontal case definitions.

2
Page : ุ62-71

Title : A Comparison among Visual, Colorimeter and Spectrophotometer for Primary Tooth Shade Matching in a Group of Thai People

Author(s) : Kanokwan Treewatthanawong, Somkamol Vanichvatana

Keyword(s) : Visual method,Colorimeter,Spectrophotometer,Primary tooth,Tooth color

Manuscript Type : Original Article (บทวิทยาการ)

Page : ุ62-71

The aim of this study was to compare the agreement and reliability among visual, colorimeter and spectrophotometer for primary tooth shade matching. Tooth color measurement was performed on the middle one-third
of the primary maxillary right central incisor of 30 participants. The visual method was done by operator 1 and 2 using Vita Classical and Vita 3D-Master shade guide. The instrumental methods were performed by operator 1 using ShadeEye NCC® colorimeter and Vita Easyshade V® spectrophotometer. Data was analyzed using McNemar test to compare the agreement between two methods and Cohen’s kappa for reliability. The results shown that the shades of primary maxillary right central incisors were A1 B1 in Vita Classical system and 0M3 1M1 1M2 in Vita 3D-Master system. The agreement of shades matched between ShadeEye NCC® colorimeter and Vita Easyshade V® spectrophotometer was 90%. There was no significantly different in agreement between these instrumental methods (P=0.25). While the agreement of shades matched between visual and instrumental methods was 1/3 of the participants. The reliability of ShadeEye NCC® colorimeter and Vita Easyshade V® spectrophotometer was in the almost perfect strength of agreement (0.81-1.00) and visual method was in the substantial strength (0.61-0.80). It can be concluded that ShadeEye NCC® colorimeter and Vita Easyshade V® spectrophotometer were more agreeable of shades matched and more reliable than the visual method in primary tooth shade matching.

3
Page : 72-85

Title : Expectation and Satisfaction of The Patients on Oral Surgery Services at The Faculty of Dentistry, Chulalongkorn University

Author(s) : Chaloemrit Phrueksotsai, Sappasith Panya, Keskanya Subbhalekha

Keyword(s) : Dental care services,Expectation,Satisfaction,Oral surgery

Manuscript Type : Original Article (บทวิทยาการ)

Page : 72-85

Patient expectations and satisfaction are indicators of success in healthcare service delivery. This research aims to study the expectations and satisfaction of patients treated at the Department of Oral and Maxillofacial
Surgery, Faculty of Dentistry, Chulalongkorn University. A secondary objective is to compare the levels of expectations and satisfaction between patients treated on National Oral Health Day and those treated at the teaching clinic, and to examine factors related to expectations and satisfaction. Patients were surveyed, including questions on general information, expectations, satisfaction regarding treatment processes, service quality, and facility and amenities. The survey received complete responses from 198 patients treated on National Oral Health Day and 206 patients from the teaching clinic. Patients’ expectations and satisfaction levels were high to very high in all aspects, with the highest levels in service quality, such as polite speech, cheerful demeanor, attentive care, service readiness, and the dentists’ expertise. Patients at the teaching clinic had higher expectations and satisfaction than those treated on National Oral Health Day. Factors related to expectations and satisfaction differed between the two groups. In the National Oral Health Day group, factors included dental care coverage and the providers related to service quality expectations. The regular dental clinic they visit and the providers were linked to satisfaction with service quality and facilities. For the teaching clinic group, income and regular dental clinic they visit were related to facility expectations, while age and income influenced satisfaction with the treatment process and service quality.

4
Page : 86-96

Title : Development of Silver Diamine Fluoride Application in Home Visiting Program among Dependent Elders in Muang Samsib District, Ubon Ratchathani Province: Action Research

Author(s) : Nilubol Panabuth, Achara Watanapa, Samerchit Pithpornchaiyakul, Yanee Jaikaeo

Keyword(s) : Action research,Silver diamine fluoride,Dental nurse,Elder,Home visiting

Manuscript Type : Original Article (บทวิทยาการ)

Page : 86-96

The objectives of this action research were to create a model for administering silver diamine fluoride to dependent elders in accordance with the concept of Kemmis & McTaggart (1988), and to study the dependent
elders’ acceptance and satisfaction following the application of silver diamine fluoride. The research methodology was divided into two sections. The first section was the development of model for using silver diamine fluoride
included studying details of the home visiting program from the dental nurse in the Muang Samsib district Ubon Ratchathani province, holding a workshop for 11 dental nurses to practice providing information before applying
silver diamine fluoride to patients and applying it to three elderly volunteers, following to the plan for applying silver diamine fluoride during home visits, and evaluation and participatory adjusting the model. The second section was the assessment of 17 dependent elders’ acceptance and satisfaction after being applied with silver diamine fluoride through interviews. The study’s findings demonstrated that the following elements should be included in the model of applying silver diamine fluoride for dependent elders combined with a home visiting program: 1. preparing knowledge and skills of silver diamine fluoride for dental practitioners, 2. supporting adequate amounts of silver diamine fluoride and equipment, and assigning a cooperator to rotate silver diamine fluoride, 3. having media to explain and illustrate about silver diamine fluoride to patients and caregivers, 4. building up a team composed of assistants to help in between operation, 5. dental practitioners should promote self-care oral hygiene for patients and caregivers and 6. the working group should have channel access to communicate about problems and learn from others. The elders and caregivers in this study accepted the use of silver diamine fluoride in the home visiting program and accepted the black staining in their both anterior and posterior teeth, after being applied with silver diamine fluoride. They believed that silver diamine fluoride can stop caries progression, reduce tooth pain and tooth sensitivity in the future, and decrease the chance of getting services in a hospital.

5
Page : 97-107

Title : Efficacy of Hand-free High-volume Evacuation Device in Reducing Bacterial Aerosol and Splatter During Endodontic Access Opening Procedure

Author(s) : Swaros Yuyuen, Soranun Chantarangsu, Ruchanee Salingcarnboriboon Ampornaramveth

Keyword(s) : Rubber dam,EasyPrep,High-volume evacuation,Dental aerosol,Hand-free high-volume evacuation device

Manuscript Type : Original Article (บทวิทยาการ)

Page : 97-107

To compare the effectiveness of aerosols reduction during endodontic access opening (OC) procedure using a hand-free high-volume evacuation device (EasyPrep) versus a rubber dam. Thirty-eight patients who required endodontic treatments of posterior mandibular teeth were recruited and divided into two groups which are rubber dams with high-volume evacuation (HVE) and EasyPrep. Air samples were collected by settle-plate technique from five different locations and at three different time points - before operation (baseline), at operation, and after operation. The number of colony-forming units (CFU) was enumerated. The genus and species of bacteria were
identified by a proteomic fingerprint using a mass spectrometer. Statistical analysis was conducted using IBM SPSS Statistics version 29.0 (IBM). At and after operation, the total CFU count was significantly higher than the baseline in both groups across various locations (p<0.05). The total CFU in the EasyPrep group was slightly higher than the rubber dam group. However, there was no statistically significant difference in total CFU count at operation between the two groups at different locations. Gram-positive cocci species including Micrococcus luteus were the most found bacteria. A hand-free high-volume evacuation device provided comparable results to rubber dam in reducing aerosols during OC procedures.

1
Page : 1-14

Title : The Comparisons of Maxillary Anterior Teeth Positions and Smile Appearances After Orthodontic Treatment Between Four First Premolar Extraction and Nonextraction in Class I Crowding Cases

Author(s) : Teerapat Wongmaneerung, Wikanda Khemaleelakul, Virush Patanaporn

Keyword(s) : nonextraction orthodontic treatment,four first premolar extraction orthodontic treatment,maxillary anterior teeth positions

Manuscript Type : Original Article (บทวิทยาการ)

Page : 1-14

The purpose of this study was to compare maxillary anterior teeth positions and smile appearances between four first premolar extraction and nonextraction in Class I crowding cases. Forty-one participants with moderate Class I crowding who had finished orthodontic treatment were recruited and divided into two groups. The first group consisted of 21 participants who had finished nonextraction orthodontic treatment, and the other group consisted of 20 participants who had finished orthodontic treatment with four first premolars extracted. Smiling pictures in frontal and lateral positions of the participants were taken. In part one, the maxillary anterior teeth positions and smile appearances were measured and analyzed. In part two, the smile esthetic of the cropped frontal smiling pictures was rated by three certificated board orthodontists and ten laypersons using the visual analog scale (VAS), and then the VAS scores were compared between the nonextraction and the extraction groups. In the assessment using smiling pictures, the ratio of the distance between the maxillary dental midline and the distal surface of the maxillary canine to the distance between the maxillary dental midline and the angle of the mouth, as well as the ratio of the distance between the left and right maxillary canine cusp to the distance between the left and right alar of the nose in four first premolar group, was significantly higher than in the nonextraction group. The difference between the horizontal distance of the left and the right alar of the nose to left and right maxillary canine cusp tip in the four first premolar extraction group was significantly lower than the nonextraction group. Maxillary canines in the four first premolar extraction group are significantly closer to the alar of the nose and the labial commissures than the maxillary canines in the nonextraction group. Maxillary teeth positions and smile appearances evaluated from the other smile parameters did not differ significantly between the two groups.

2
Page : 15-23

Title : Oral Health and Health Related Quality of Life in Patients with Removable Dentures

Author(s) : Piya-anong Wannakhaw, Nareudee Limpuangthip, Supaboon Purnaveja

Keyword(s) : denture,dental prosthesis,oral health,quality of life,tooth loss

Manuscript Type : Original Article (บทวิทยาการ)

Page : 15-23

This cross-sectional study was conducted in 80 patients at prosthodontics department, faculty of dentistry, Chulalongkorn University in 2022. Two outcomes, oral health (OHRQoL) and health-related quality of life (HRQoL), were interviewed using the Oral Impacts on Daily Performances and the World Health Organization Quality of Life-Bref index, respectively. Independent variables, collected by intraoral examination and interview, were general characteristics of patients, tooth loss status (number of posterior occluding pairs and remaining natural teeth), and removable denture status.  The association between each outcome and independent variables were analyzed using Mann-Whitney U or Kruskal-Wallis test. The correlation between OHRQoL and HRQoL score was calculated to determine the Spearman correlation coefficient. Data were analyzed at a 5% significance level. The results showed that a greater number of posterior occluding pairs (p = 0.019) and natural teeth (p = 0.001) and having functional denture (p = 0.001) were associated with better OHRQoL. Meanwhile, higher income (p = 0.09) and better medical conditions (p = 0.012) were associated with HRQoL. There was a correlation between psychological dimension of OHRQoL and overall HRQoL (Spearman rho = -0.217; p = 0.045). In conclusion, tooth loss and poor denture status were associated with worse OHRQoL. However, the OHRQoL and HRQoL were not directly related.

3
Page : 24-33

Title : Effects of Carious Dentin Surface Preparation on Microtensile Bond Strength Following Silver Diamine Fluoride Application in Permanent Tooth

Author(s) : Jitrekha Samphantharat, Natphajee Norasettrakoon, Sarunya Kladkaew

Keyword(s) : Microtensile bond strength,Natural carious dentin,Posterior permanent tooth,Resin composite,Silver diamine fluoride

Manuscript Type : Original Article (บทวิทยาการ)

Page : 24-33

The aim of this in vitro study was to investigate the effect of the surface preparation by polishing on the microtensile bond strength of resin composite to carious dentin treated with silver diamine fluoride. Thirty human
posterior teeth with natural carious dentin were stored in artificial saliva for 14 days after application of 38 percent silver diamine fluoride on the carious lesion. After 14 days, the samples were sectioned in half through the middle of the carious lesion and randomly assigned to either the test or the control group (n=30), with or without superficial dentin polishing by 600-grit silicon carbide paper. Rinsing the specimens were performed prior to the bonding with composite resin using universal adhesives in etch-and-rinse mode. Following the bonding, the specimens were sectioned perpendicularly to the interface to produce sticks (1 mm x 1 mm in dimensions) and submitted to the microtensile bond strength testing. The bond strength data were obtained after 24-hour water storage by a universal testing machine, followed by the failure mode assessment with a stereomicroscope and a scanning electron microscope. Data were analyzed by independent samples T-test. The mean and standard variations of microtensile bond strength in the control and the test group, superficial dentin polishing, were 13.29 ± 11.67 MPa and 17.80 ± 12.34 MPa, respectively (p=0.000). The superficial polishing prior to the bonding affects the bond strength of resin composite to carious dentin of permanent tooth treated with silver diamine fluoride and promisingly encourages the bonding efficacy.

4
Page : 34-45

Title : Wear Resistance and Surface Roughness of Injectable Resin Composites after Chewing Simulation

Author(s) : Napat Lapaschaone, Chaiwat Maneenut

Keyword(s) : Flowable resin composite,Injectable resin composite,Resin composite,Surface roughness,Wear resistance

Manuscript Type : Original Article (บทวิทยาการ)

Page : 34-45

The purpose of this study was to evaluate wear resistance and surface roughness of injectable resin composites after undergoing chewing simulation and compared with those of conventional flowable resin composites and conventional paste resin composites. Ten specimens of each product from three different types: 1) two injectable resin composites (GU, BI), 2) two conventional flowable resin composites (SF, BF) and 3) two conventional paste resin composite (GP,BT), were fabricated in a sample holder and the top surface was polished using silicon carbide papers. The surface topography of the specimens was profiled using a three-dimensional contact profilometer before being subjected to a chewing simulation at 120,000 cycles with a flat enamel antagonist. The surface topography of the specimens was profiled again to determine the wear resistance and surface roughness (Ra). SEM was used to evaluate the surface characteristics of the specimens. After chewing simulation, the conventional flowable resin composites (BF and SF) showed lower wear volume (0.066±0.017 mm3, 0.084±0.015 mm3, respectively) than the others. The lowest maximum wear depth was found in the BF group (23.04±4.243 μm). The injectable resin composites (GU and BI) demonstrated a significantly (P<0.05) lower mean Ra value (0.147±0.036 μm, 0.168±0.051 μm respectively) than the others. The SEM micrographs of the GU group showed the smoothest surface texture while the BT group demonstrated the largest area of wear as well as the most prominent cracks and plucks of fillers. The baseline surface roughness and surface roughness after chewing simulation have a positive correlation (R=0.367, p=0.004). Wear volume and maximum wear depth have a positive correlation as well (R=0.892, p=<0.001). There was no
correlation between wear volume and surface roughness. In conclusion, the injectable resin composites exhibited material dependent wear resistance which might relate to intrinsic factors of the material. In addition, they exhibited

5
Page : 46-54

Title : Knowledge, Attitude, and Practice of Infection Control Regarding COVID-19 among Thai Dental Students

Author(s) : Pornnatcha Suanjit, Pornchita Angsawetrungruang, Thanaporn Chansamorn, Neeracha Sanchavanakit, Keskanya Subbalekha

Keyword(s) : Attitude,COVID-19,Dental practice,Infection control,Knowledge

Manuscript Type : Original Article (บทวิทยาการ)

Page : 46-54

The objective of this study was to investigate the knowledge, attitudes, and practices concerning COVID-19 dental practice guidelines. A questionnaire was distributed to undergraduate dental students at the Faculty of Dentistry, Chulalongkorn University, who practiced in the clinic during the academic year 2022 through online platforms. Data was collected during December 2022 and February 2023. One hundred and fifty-seven responses were received and analyzed, resulting in a 53.95% response rate. The average knowledge score was 6.52 out of 10, with a standard deviation of 1.175. Among all respondents, 53.5% provided all correct answers related to general knowledge of COVID-19. However, only 10.2% and 8.9% accurately answered all questions regarding self- and interpersonal transmission prevention, and environmental contamination prevention, respectively. More than 80% of the participants exhibited a positive attitude toward infection control protocols. In contrast, 65.6% and 46.5% expressed positivity towards social distancing and COVID-19 risk assessment questionnaires, respectively. In accordance with the COVID-19 dental practice guidelines, practices that were consistently followed by over 80% of the respondents included wearing personal protective equipment during dental treatments, instructing patients to use antimicrobial mouthwash before treatment, and disinfecting dental unit surfaces before and after procedures. Additionally, more than 50% of UGs requested a laundry delivery room for long-sleeved gowns near treatment areas, as well as an increase in the availability of alcohol gel and air purifiers. In conclusion, while UGs exhibited positive attitudes, their knowledge and adherence to COVID-19 dental guidelines were lacking. Urgent actions are needed to enhance UGs’ understanding and compliance with these guidelines.