Predictors of apical periodontitis in root canal treated teeth from an adult Nepalese subpopulation: a cross-sectional study.

BACKGROUND: Endodontic literature search revealed that no study has been conducted to evaluate the prevalence of apical periodontitis (AP) in root canal treated teeth from an adult Nepalese population of Madhesh Province. Consequently, little is known about the extent and risk factors associated with it. This study aimed to determine AP prevalence in root canal treated teeth from an adult Nepalese subpopulation and to analyze the related risk factors including age, sex, tooth type, type of coronal restoration and quality of root canal treatment and coronal restoration as predictors of AP. METHODS: Digital panoramic radiographs were evaluated. Periapical status of 300 root canal-treated teeth was scored by using the periapical index. The quality of root canal treatment and coronal restorations were categorized as adequate or inadequate through radiographic and clinical evaluation. The data were analyzed using univariate and multivariate logistic regression models. RESULTS: Prevalence of AP in the present study was 31.7%. In 45.7% of the treated teeth, quality of root canal treatment was adequate whereas 46% of the cases had adequate coronal restorations. Multivariate logistic regression analysis revealed statistically significant associations and remarkably increased risk for AP in teeth with inadequate root canal treatment (odds ratio [OR] = 7.92; 95% CI: 3.96-15.82; p < 0.001) whereas lower risk for AP was found in females (OR = 0.51; 95% CI: 0.28-0.90; p = 0.021) and in teeth restored with crown (OR = 0.22; 95% CI: 0.09-0.51; p < 0.001) and filling (OR = 0.18; 95% CI: 0.08-0.42; p < 0.001). Quality of coronal restoration, tooth type and age of the patient were not found to be the predictors of AP. CONCLUSIONS: Within the limits of this study, a high prevalence of AP and poor overall quality of root canal treatment and coronal restoration was found in the subpopulation studied. Quality of root canal treatment, type of coronal restoration and sex of the patient are significant predictors of possible AP development in root canal treated teeth. Substantial efforts are needed to improve the endodontic treatment standards.

Comparison of Mechanical Properties of PEEK and PMMA: An In Vitro Study.

AIM: Evaluation and comparison of flexural strength and hardness of heat-cured polymethylmethacrylate (PMMA) denture base with polyetheretherketone (PEEK). MATERIAL AND METHODS: A total of 80 samples of PEEK and PMMA were prepared and divided into two groups: group A and group B, of 40 each. Both the groups were further divided into subgroups consisting of 20 samples of PMMA and PEEK. The group A specimens were tested for flexural strength by universal testing machine (UTM), and group B samples were subjected to hardness test using Vickers microhardness tester. The values obtained were subjected to statistical analysis. The readings were subjected to an unpaired t-test for comparison of flexural strength and hardness of PEEK and PMMA. RESULT: The flexural strength of PEEK was 183 MPa, while that of PMMA was 84 MPa. The hardness of PEEK and PMMA was 24 VHN and 19.4 VHN, respectively. CONCLUSION: It was observed that PEEK can be a potential denture base material with superior properties as compared to PMMA. Further researches are needed to be carried out. CLINICAL SIGNIFICANCE: PEEK as a denture base exhibits adequate flexural strength prolonging its clinical longevity and overcoming the most common reason for the failure of PMMA denture base that results in fracture.