ABSTRACT
Context: Whenever there is loss of teeth and occlusion, it triggers a change in the functional and structural relationship of the mandible. Various physiologic factor such as age and changes in occlusion lead to specific remodeling changes in the temporomandibular joint (TMJ). Aims: The aim of this study was to evaluate and compare the influence of dentition on condyle‑fossa position by comparing this variable in dentulous and edentulous subjects using lateral cephalogram. Settings and Design: The study was conducted on 25 dentulous and 25 edentulous subjects, comprising of males and females, visiting Yenepoya University, Mangalore. Subjects and Methods: The age ranges of dentulous subjects were 25–30 years and edentulous subjects of 45–65 years with 1–5 years of edentulousness were chosen. Lateral cephalograms were taken, and various reference lines and planes were used to determine the center of condyle and center of the glenoid fossa. Statistical Analysis Used: The results were analyzed by SPSS version 7.0 (SPSS Inc., Chicago) and statistical analysis used was t‑test. Results: Condyle was placed upward and forward, and glenoid fossa was situated more anteriorly in edentulous subjects compared to dentulous subjects. Conclusions: This study supports the concept that TMJ is an articular triad with two points of contact provided by TMJ and third contact by the dentition. Alteration in any one of these contact points will produce secondary morphological changes in other two points.
ABSTRACT
Context: Materials used for the fabrication of interim restorations must satisfy biological, esthetic, and functional needs. Strength and wear resistance are two important physical properties contributing to clinical efficiency. Aim: The objective of this in vitro study was to evaluate and compare the flexural strength and hardness of five resins used for the fabrication of interim fixed partial dentures. Materials and Methods: Five groups containing ten specimens of each material were fabricated in customized brass split molds with dimensions 65×10×2.5 mm. The materials subjected to this study were Revotek LC™ (group RLC), Protemp II™ (group PSC), Acry-lux V™ with regular monomer (group AHC), Acry-lux V™ with self-cure monomer (group ASC), DPI™ self-cure tooth molding powder (group DSC). The specimens were polymerized according to the manufacturers' instructions and were evaluated for flexural strength using a universal testing machine and for hardness using a microhardness tester. Statistical Analysis: The mean of the five groups was compared using one way analysis of variance (ANOVA) and pair-wise comparison was done using Tukeys honesty significance difference (HSD) test. P≤.05 was considered to be statistically significant. Results: Flexural test results showed that group AHC (79.8950 MPa) had the highest flexural strength followed, in descending order, by group PSC (77.9700 MPa), group ASC (63.7150 MPa), group RLC (58.8110 MPa), and group DSC (51.9840 MPa). Statistically, the difference was found to be highly significant among all the groups. The hardness tests showed that group AHC (17.6900 KHN) had the highest hardness value followed, in descending order, by group PSC (15.9400 KHN), group RLC (12.6000 KHN), group ASC (11.2500 KHN), and group DSC (8.7700 KHN). Statistically, the difference was found to be highly significant among all the groups. Conclusion: Group AHC, representing a heat-polymerizing resin, showed the highest flexural strength and hardness values as compared to auto-polymerizing resins and light-polymerizing resin.