ABSTRACT
Introduction: The use of different materials and techniques has been studied to decide the safest quantum of reduction of the occlusal surfaces. However, these methods provide limited information as to the actual amount of reduction with limitations in accuracy, accessibility and complexity. Objective: The objective of this study was to compare and evaluate the reliability of the most commonly used occlusal registration wax that with polyether bite registration material as a guide for occlusal reduction required during tooth preparations. Materials and Methods: For the purpose of this study, 25 abutment teeth requiring tooth preparation for fixed prosthesis were selected and tooth preparations carried out. Modeling wax strips of specific dimensions were placed onto the cast of prepared tooth, which was mounted on maximum intercuspation on the articulator and the articulator was closed. The thickness of the wax registration was measured at three zones namely two functional cusps and central fossa. Similar measurements were made using the polyether bite registration material and prosthesis at the same zones. The data was tabulated and was subjected to statistical analysis using anova test and Tukey honestly significant difference test. Results: The differences in thickness between wax record and prosthesis by 0.1346 mm, whereas the difference between polyether and prosthesis was 0.02 mm with a P value of 0.042, which is statistically significant. This means that the wax record was 8.25% larger than the prosthesis while polyether was just 1.27% larger than the prosthesis. Conclusion: The clinical significance of the above analysis is that Ramitec polyether bite registration material is most suitable material when compared with commonly used modeling wax during the tooth preparation.
ABSTRACT
Introduction: The prevalence of group function and canine guided occlusion is common in natural dentition, but cross arch balance is not often seen. Hence, a study was carried out with following objectives: Analysis of incidence of cross arch balance in different age groups and working side occlusal wear facets in following subjects. Materials and Methods: A total of 200 patients with natural dentition were included in the study. Subjects with cross arch balance were analyzed for working side occlusal wear facets. Data were analyzed statistically by Chi-square test. Results: The incidence of cross arch balance in the study group was 0.7%. On examination, subjects with group function on the working side and cross arch balance on the non-working side had more occlusal wear facets. Conclusion: From the study, it was observed that there was no significant variation in the number and extent of wear facets between the cross arch and without cross arch subjects due the smaller sample size hence it was difficult to conclude the relationship non-working side contact as interference and its influence in wearing of dentition in this study.
ABSTRACT
Background and Objectives: This study was done with the objectives to determine the range of functional zone between the intercuspal positions and edge to edge position, the range of incomplete and complete disclusion of posterior teeth in canine-guided occlusion, and to have a gender comparison and comparison between right and left sides of the obtained values. Materials and Methods: Thirty-five subjects showing canine-guided occlusion and Angle's class I canine and molar relation were chosen for the study. Maxillary midline and a corresponding line on the mandible were marked in maximum intercuspation with marker pen in the patient's mouth. Lines from 1 to 5 mm were marked on maxillary central incisor with marker pen. A dental floss was looped around the distal surface of mandibular last molar and the subject was asked to make left lateral movement (working side) at 1-mm intervals. The point at which floss was freed posteriorly was considered as initial disclusion and the point at which edges of maxillary and mandibular canines contacted was considered as complete disclusion. Results: Most of the male and female subjects in the study showed progressive disclusion on right side and delayed disclusion on left side. The range of complete disclusion was 3-4 mm in males and 2-3 mm in females irrespective of the side. The range of functional zone was 1-4 mm irrespective of side or gender. Interpretation and Conclusion: There is a need to redefine canine guidance in terms of immediate disclusion, delayed disclusion, and progressive disclusion.
ABSTRACT
Aims : The application of a paint-on die spacer onto the dies prior to the fabrication of cast crowns is an acceptable procedure to improve the fit of the restoration. The primary purpose of this study was to evaluate the variation in thickness of different brands of die spacer based on the effect of storage time and application of additional layers. Materials and Methods: Dies were duplicated from a master model of ivorine teeth, with a full ceramic preparation. Dies obtained were then painted with one, two, and three coats of each brand of die-spacers separately. These dies were embedded in die stone and sectioned bucco-lingually. The same procedure was done after three and six months. The thickness of the paint on die spacer was measured at five points on the die using an optical microscope, and the data were statistically analyzed. Results and Conclusion : There was a definite variation in the thickness of the die spacer with all the three brands and at various points on the die. Two coat thicknesses were found to be in the range of tolerance of 20-40 microns. Thickness at occlusal groove was noted to be the maximum with least at occlusoaxial line angles. Thickness also showed a very significant increase when bottles were stored for a period of three to six months and then applied.