Khon Kaen University Dental Journal

Fracture Toughness of Posterior Resin Composites

2025-01-14T18:22:41+07:00

Objective: This study aimed to compare the fracture toughness of seven types of resin composites used for posterior tooth restoration: Tetric N Ceram Bulk Fill (TB), G-ænial Posterior (GP), Fill-Up (FU), X-tra Fil (XF), Filtek Bulk Fill (FB), everX Posterior (EXP), and Filtek Z350XT (Z350XT).

Materials and Methods: Single-edge notched beam resin composite specimens were prepared in an 2x25x2 mm acrylic mold (10 specimens in each group). All specimens were immersed in distilled water at 37°C for 24 hours before testing. Fracture toughness was measured using a three-point bending test with a universal testing machine. The fracture toughness of each resin composite group was compared using the Kruskal-Wallis test, and differences between pairs were analyzed using the Mann-Whitney U test at a 95% confidence level.

Results: The results showed that the fracture toughness values (MPa·m^0.5), ranked from lowest to highest, were TB, GP, FU, XF, Z350XT, FB, and EXP, respectively. The study found that EXP had significantly higher fracture toughness than TB, GP, and FU but was not significantly different from FB, Z350XT, and XF. Meanwhile, XF, Z350XT, and FB had significantly higher fracture toughness than TB and GP.

Conclusion: The study concluded that the seven resin composites have significantly different fracture toughness values, with the fiber-reinforced EXP presented the highest fracture toughness.

Development of Butterfly Pea-Aloe Vera Mouthwash with Antimicrobial Activity Against Streptococcus mutans

2025-06-16T10:29:57+07:00

Objective: Dental caries is the most common oral health issue in the Thai population, primarily caused by Streptococcus mutans (S. mutans). Although chlorhexidine (CHX) mouthwash is the gold-standard antibacterial agent for reducing dental plaque and pathogenic microorganisms such as S. mutans, it is associated with side effects such as tooth discoloration, altered taste, dry mouth, and oral burning sensations. Consequently, plant-based extracts are increasingly being explored as safer alternatives. Previous studies have demonstrated that both Butterfly pea and Aloe vera possess antibacterial activity against S. mutans; however, no study has evaluated the efficacy of a Butterfly pea–Aloe vera solution. Therefore, this study aims to assess the effectiveness of Butterfly pea-Aloe vera solutions against S. mutans.

Materials and Methods: To evaluate the antimicrobial effect of Butterfly pea–Aloe vera solutions against S. mutans, thirteen groups were tested using a modified broth dilution assay and the drop plate technique. These groups included three Butterfly pea solutions at 400 (BP400), 200 (BP200), and 100 mg/mL (BP100); three Aloe vera solutions at 100 (AV100), 50 (AV50), and 25 mg/mL (AV25); four formulations of Butterfly pea–Aloe vera solutions (BP200_AV50, BP200_AV25, BP100_AV50, BP100_AV25); a bacterial suspension (experimental control); CHX (positive control); and deionized water (DI, negative control). Colony-forming units (CFU/mL) were analyzed using the Kruskal–Wallis and Mann–Whitney U tests (a=0.05).

Results: All Butterfly pea solutions (BP400, BP200, BP100) and combined Butterfly pea–Aloe vera solutions (BP200_AV50, BP200_AV25, BP100_AV50, BP100_AV25) significantly inhibited S. mutans compared to the DI group, with no significant difference between the Butterfly pea group and the Butterfly pea–Aloe vera group. All Aloe vera solutions (AV100, AV50, AV25) showed no significant inhibition and performed similarly to the DI group. The CHX group exhibited the highest antibacterial activity.

Conclusion: Butterfly pea solution at 100 mg/mL and the Butterfly pea–Aloe vera solution at BP100_AV25 show promise as natural alternatives to chemical-based mouthwashes for daily caries prevention. Further development will focus on BP100_AV25 as a ready-to-use, chemical-free herbal mouthwash, aiming to harness additional biological properties of the two plants, such as anti-inflammatory, wound-healing, and remineralization effects.

Prevalence and Associated Factors of Signs and Symptoms of Temporomandibular Disorders in Students, Sirindhorn College of Public Health Chonburi.

2025-06-03T09:37:36+07:00

Objective: To evaluate the prevalence and associated factors of signs and symptoms of temporomandibular disorders in students at Sirindhorn College of Public Health Chonburi

Materials and Methods: The participants consisted of 255 students aged 18 to 30 years from Sirindhorn College of Public Health Chonburi, from January to October 2024. The tools consisted of general information, a self-assessment of stress (ST-5), and a 10-item temporomandibular disorders questionnaire. Descriptive statistics, including frequency, percentage, mean, and standard deviation. The multiple logistic regression was used to determine the correlations between the variables with a significance level of 0.05.

Results: The majority of the students were female, accounting for 84.30%, with an average age of 19.67±1.48 years. We found that 36.10% of students had signs and symptoms of temporomandibular disorders. The top three most commonly reported problems were hearing clicking or grinding sounds in the jaw joint (15.70%), followed by frequent headaches, neck pain, or toothaches (14.50%), and a feeling of changes in the occlusion (12.90%), respectively. In terms of related factors, it was found that academic program, bruxism, clenching, and stress levels were significantly associated with signs and symptoms of temporomandibular disorders in students (p<0.05). Dental public health students are 2.57 times more likely to have temporomandibular disorders than students in other programs. Students with bruxism, clenching, and high stress are 2.40, 3.05, and 2.56 times more likely to have temporomandibular disorders, respectively. However, gender, consuming hard or chewy foods, unilateral chewing, and a history of orthodontics were not associated with signs and symptoms of temporomandibular disorders in students.

Conclusion: Academic program, bruxism, clenching, and stress levels were significantly associated with signs and symptoms of temporomandibular disorders in students. Dental professionals should prioritize providing appropriate education regarding temporomandibular disorders to the student population, including prevention strategies that may be implemented from the early stages.

Factors Influencing Decision on Using Dental Service of Elderly People at Geriatric Clinic, Phan Hospital, Chiangrai Province.

2025-08-08T11:36:22+07:00

Objective: This study aimed to examine the factors influencing decision on using dental service of elderly people at the Geriatric Clinic, Phan hospital.

Materials and Methods: This cross-sectional study involved 160 elderly people aged 60 years and above, including homebound and socially active individuals, who were screened for geriatric syndromes at the Geriatric Clinic of [hospital name withheld]. Data were collected using a structured interview questionnaire based on the conceptual integration of Jaturongkakul’s consumer decision-making model and the dental service utilization model by Davidson and Andersen. The data collection was conducted between October 1, 2024, and March 31, 2025. Descriptive statistics such as frequency distribution, percentage, mean, median, and standard deviation were used. Inferential statistics included Chi-square tests or Fisher’s exact tests for association analysis. In addition, the factors influencing the decision on using dental service of elderly people were analyzed using binary logistic regression analysis.

Results: The study found that after controlling for various factors, the factors that significantly influenced the decision on using dental service of elderly people were statistically significant at the 0.05 level. These included marital status (OR=2.67, 95% CI: 1.05–6.77), financial burden (OR=3.05, 95% CI: 1.21–7.69), perceived need for dental care (OR=7.60, 95% CI: 2.89–19.95), perception of available dental service (OR=3.38, 95% CI: 1.25–9.11), influence of dental personnel (OR=2.62, 95% CI: 1.02–6.74), and perceived barriers to dental care (OR=3.74, 95% CI: 1.06–11.36). These factors can explain 52.2% of the likelihood of elderly people decision on using dental care.

Conclusion: Key factors influencing decision on using dental service of elderly people at the Geriatric Clinic of [hospital name withheld] included marital status, financial burden, perceived need for dental care, perception of available dental service, influence from dental personnel, and perceived barriers to care. The researcher recommends that dental personnel take a proactive approach by providing information that raises awareness of the necessity of using dental service among elderly people and by promoting dental service to ensure that elderly people are informed, thereby increasing their decision to using dental service.

Accuracy of Linear Measurements with Different Cone Beam Computed Tomography

2025-05-30T09:32:49+07:00

Objective: Dental radiography, both 2D and 3D, plays a significant role for dental examinations. Recently, 3D images (Cone-Beam Computed Tomography; CBCT) have been widespread used in dentistry. Various machines with different productions and vendors may affect the qualities and outcome of CBCT images. To study the qualities of CBCT images from different machines by using the accuracy of linear measurement method is set up for this study’s objective.

Materials and Methods: This is an in-vitro experimental study comparing the accuracy of linear measurements from two CBCT scanning machines. The 64 printing models made of polylactic acid (PLA) material were built up with actual width, length, and height as the control group. The models were scanned by two CBCT machines with same parameters and stored in medical PACS; Infinitt®. The width (A) and length (B) were measured from an axial plane and the height (H) was measured from a sagittal plane.

Results: Statistical analysis with the repeated ANOVA showed the mean differences between the actual model and CBCT images from Planmeca Viso G7^® and Carestream 8100SC 3D^® were 0.04 ±0.08 mm (p<0.001) and -0.15 ±0.40 mm. (p<0.001) respectively. The linear lengths measured on the two CBCT machines were significantly different.

Conclusion: The linear lengths measured on CBCT images of the Planmeca Viso G7^® showed less difference from the model than those of the Carestream 8100 SC 3D.

Mandibular Anatomical Risk Factors for Bad Split During Sagittal Split Ramus Osteotomy

2025-07-29T10:59:17+07:00

Objective: This study aimed to assess the correlation between mandibular anatomy and the occurrence of bad splits in Sagittal split osteotomy (SSO).

Materials and Methods: Pre-surgical CBCT images of 10 patients with bad split (bad split group) and 40 patients without bad split (normal group) were evaluated. Anatomical parameters of the mandible related to the osteotomy line were measured. Conditional logistic regression and receiver operating characteristic (ROC) curve analyses were performed.

Results: Results showed that a shorter height from the lingula to the fusion of buccal and lingual cortices (HLBC; p=0.009) and thicker distance between outer surfaces of buccal and lingual cortical plates of ramus at the level of the lingula (BTRL; p=0.028) were significantly associated with the occurrence of a bad split. ROC analysis revealed an HLBC cut-off of 7.5 mm.

Conclusion: This study suggests that patients with a shorter height from the lingula to the fusion of buccal and lingual cortices less than 7.5 mm are at higher risk of bad splits during SSO. Surgeons should exercise caution in such cases to minimize complications.

Quality of Root Canals Filled with a Calcium Silicate-Based Sealer using Different Placement Methods: A Micro-CT Study

2025-09-10T15:43:33+07:00

Objective : This study aimed to compare the volumes of voids and gaps in root canals fillings obtained with the single-cone technique using a calcium silicate-based sealer placed by different methods, as assessed by micro-computed tomography (micro-CT).

Materials and Methods : Sixty extracted mandibular premolars with oval-shaped canals were prepared using nickel-titanium rotary instruments to an apical size of 40/.04 and randomly assigned to three groups according to the sealer placement methods: ST, single-cone technique with a disposable tip; STU, single-cone technique with a disposable tip and ultrasonic activation; and STL, single-cone technique with a disposable tip and a lentulo spiral (n= 20 per group). Each obturated tooth was scanned with micro-computed tomography to evaluate the presence of voids and gaps. The percentage volume of voids and gaps was calculated at the coronal, middle and apical levels. Data were statistically analyzed using the Kruskal-Wallis test and linear mixed model with Bonferroni adjustment at a 5% significance level.

Results : The STL group had the highest total percentage volume of voids (3.971%), whereas the ST group had the highest total percentage volume of gaps (1.428%). Across the entire canal, no significant between-group differences were observed for the percentage volume of either voids or gaps (p>0.05). At the coronal level, the STL group exhibited a significantly greater percentage volume of voids than the other groups (p<0.05), and within the STL group the coronal was significantly higher than the middle and apical levels (p<0.05). No significant differences in percentage volume of gaps were detected between groups or among canal levels (p>0.05).

Conclusion : Within the limitation of this study, no significant differences were found in overall void and gap formation among the three sealer placement methods. However, the use of a lentulo spiral in oval-shaped canals was associated with the highest void volume at the coronal level.

Antibacterial Activity of Mitragyna Speciosa Korth. Extract on Streptococcus mutans

2025-09-11T09:17:04+07:00

Objective: The purpose of this study aimed to evaluate the antibacterial effect of Mitragyna speciosa Korth. (Kratom) extract on Streptococcus mutans.

Materials and Methods: Crude extracts of kratom leaves were prepared using four extraction methods: maceration with 95% ethanol, maceration with 50% ethanol, decoction, and squeezing. S. mutans cultured in Mueller Hinton Broth was plated on Mitis Salivarius Agar. Paper discs containing kratom extracts from the four different extraction methods, and 0.12% chlorhexidine (as a positive control) were placed on agar plates. The inhibition zones were measured in millimeters, with clear zones indicating bacterial growth inhibition. The experiments were performed in triplicate. Data were recorded numerically and supplemented with images for analysis.

Results: The experiments indicated a similar clear zone area in shape and size. A clear inhibition zone was seen around the filter disc soaked in 0.12% chlorhexidine, indicating its antibacterial activity against S. mutans, while discs soaked in other extracts allowed normal bacterial growth. Red and white kratom extracts were unable to inhibit bacterial growth regardless of the extraction method used (maceration with 95% or 50% ethanol, decoction, or squeezing). However, reduced clear zones were observed around paper discs soaked with extracts from white kratom (squeezing method) and red kratom (maceration with 95% ethanol), which exhibited a slight tendency to inhibit bacterial growth.

Conclusion: Despite previous reports of antibacterial properties, kratom extracts obtained by the extraction methods in this study probably had a slight or no effect on S. mutans. Further investigation will provide more information on the effect of kratom on S. mutans.

Measurement of Distances between Anterior Mandibular Structures in Thai Patients and Osteotomy Recommendation: A Cone Beam Computed Tomography Analysis

2025-10-06T09:36:34+07:00

Objective: The primary objective is to measure distances between key anatomical landmarks in the anterior mandible of Thai adults and analyze variations based on sex and skeletal classification using Cone-Beam Computed Tomography (CBCT. The secondary objective is to establish normative data for this region among the Thai population.

Materials and Methods: An observational study was conducted using CBCT scans from Thai adults with all lower anterior teeth present. Measurements focused on the distances from the inferior mandibular border to the genial tubercles and the anterior loop among others.

Results: A total of 186 CBCT scans were analyzed. No significant differences were found between left and right sides. Males showed significantly greater measurements than females (P≤0.021), except at the central incisor apex to genial tubercle (P=0.073, 0.192). No significant differences were observed among skeletal classes (P=0.099–0.987).

Conclusion: This study identified significant gender-related anatomical differences in the anterior mandible, with consistently greater measurements in males, while no significant differences were observed among skeletal classes. Based on these findings, recommended osteotomy safety margins from the inferior border are 19 mm in men and 17–17.5 mm in women for the midline and lateral incisor regions, and 15 mm in men and 13.5 mm in women for the canine region. Fixed safety margins are not recommended in the anterior loop area due to anatomical variability; therefore, individualized CBCT assessment is strongly advised. These reference values may enhance surgical safety in anterior mandibular procedures.

Treatment of Tooth Autotransplantation in a Cleft Lip and Cleft Palate Patient: A Case Report

2025-04-23T10:53:38+07:00

Tooth autotransplantation into cleft site in the cleft lip and cleft palate patient presents numerous challenges, primarily due to insufficient alveolar bone in this area that has undergone bone grafting for a long period while bone augmentation is often difficult. This case report details the tooth autotransplantation procedure in a cleft lip and cleft palate patient who exhibited an ectopically erupted maxillary right canine. The patient also had limited alveolar bone width to support a transplanted tooth. Treatment involved the extraction of the maxillary right canine and its transplantation to the congenitally missing right lateral incisor area, corresponding to a cleft area that had undergone bone grafting four years ago. To support a transplanted tooth, alveolar ridge expansion was performed. Root canal treatment was initiated three weeks post-transplantation. The outcome demonstrated successful healing of the transplanted tooth and periodontium, with no signs of ankylosis. The transplanted tooth is functional and the patient is undergoing orthodontic treatment. This article reviews relevant literature on tooth autotransplantation in cleft lip and palate patient and discusses the outcome of this case.