ABSTRACT
Purpose: The purpose of the study was tocompare measurements of maxillary occlusal cant obtained through facebow transfer and through lateral cephalogram.Method:40 subjects were included in this study according to inclusion and exclusion criteria and divided into two groups: dentulous and edentulous. For edentulous subjects, all the steps of complete denture fabrication were carried out and finished dentures weredelivered. Alginate impressions were now made for all the subjects (with complete denture worn in edentulous cases) for both upper and lower arches. The study was conducted in two parts. Facebow transfer was done next and casts were mounted. In first partof the study, sagittal inclination was measured after facebow transfer. After mounting of the casts, four points were marked to measure the inclination of the occlusal plane. In second part, cephalometric evaluation of occlusal plane and Frankfurt horizontal plane was carried out. Angle between Frankfurt horizontal plane and the occlusal plane was maxillary occlusal cant. which was evaluated by tracing.Paired t test was used to compare mean facebow values and lateral ceph values in edentulous subjects. Intergroup comparison between lateral ceph and mean facebow values between dentulous and edentulous subjects was evaluated using independent t test.Results:Facebow measurements gave comparatively higher values in both dentulous and edentulous patients and are subjected to less variation as compared to the lateral cephalogram values p<0.0001.Conclusion:The occlusal plane angle of lateral cephalogram was found to be significantly different from angle obtained through facebow transfe
ABSTRACT
This study investigated the color stability of reline resin after two methods of disinfection i.e microwave disinfection and chemical disinfection. A stainless steel moldwith a breakaway compartment (10 mm in diameter by 0.7 mm thickness) was made to fabricate specimens of various resins. Each material was mixed according to manufacturer’s instructions and applied into the mold. Prior to color stability testing, specimenswere cleaned in distilled water for 20 minutes to kill any microorganisms that may had contaminated the discs during fabrication. And then specimens were immersed in Sodium Perborate Monohydrate 200 ml of solution for 15 days and microwaved for 15 days sothat it is comparable to chemical disinfection soaking. The color stability of each specimen was measured again using spectrophotometer and values were obtained. The data of ∆E, ∆L, ∆b, ∆a were analysed by 2 way repeated measures ANOVAs test. Significant statistic changes in color parameters ∆L, ∆a, ∆b of the reline resin DPI, Ufi Gel Hard And Kooliner were observed when dentures were disinfected by Sodium Perborate Monohydrate 2% solutions. The color stability of the reline resin was influenced by time, regardless of disinfection or non disinfection. This can be attributed to bleaching (whitening) effect of reline material. Discoloration Original Research Article of resin based materials may be caused by intrinsic or extrinsic factors. Intrinsic factors are related to internal alterations in material resulting from physicochemical reactions or residual monomer oxidation with time. Thus the initiator, quantity and type of monomer and the polymerisation efficiency can affect the color stability of resin based materials. The color stability deviation value ∆E significantly increased to maximum for chemical disinfectant, least for Control group and intermediate for microwaved group. Ufi Gel showed the highest deviation ∆E and Control Group showed the lowest deviation according to results