Comparative Evaluation of Osseodensification Versus Conventional Osteotomy Technique on Dental Implant Primary Stability: An Ex Vivo Study.

Purpose One of the commonest treatment options for replacing missing teeth is a root-form implant. Clinically, the key mechanical factor in achieving success is primary stability. This ex vivo study aims to evaluate whether osseodensification method will achieve good primary stability or the conventional drilling protocol. Methods Fresh iliac bone of the sheep was selected similar to D3 and D4 bone densities. A total of 22 osteotomy sites were prepared in the bone sample, of which 11 were prepared by osseodensification method (test group) and other 11 by conventional undersized drilling (control group). Primary stability was measured using insertion torque (IT), resonance frequency analysis (RFA), and reverse torque values (RTVs) by measuring implant stability quotient (ISQ). The recorded data were statistically analyzed using Statistical Package for the Social Sciences (SPSS) Version 22.0. The differences between groups were compared using the Mann-Whitney U test and independent t-test. The Pearson correlation coefficient test was performed to measure the linear relationship between two variables. The statistical significance level was established at p<0.05. Results When the correlation among IT, RTV, and ISQ was measured, a statistically significant correlation between IT and RTV (p=0.001) and between IT and ISQ (p=0.0001) was observed. A statistically significant (p=0.014) correlation between RTV and ISQ was also found. Conclusion Osteotomy prepared by osseodensification method showed higher IT, RTV, and ISQ values than the conventional undersized group.

The Influence of Thermal Curing Cycles on the Color Stability of Unfilled Polymethyl Methacrylate Teeth.

PURPOSE: The purpose of this study was to evaluate the influence of water bath polymerization cycles on the color stability of unfilled polymethyl methacrylate (PMMA) teeth. MATERIALS AND METHODS: A total of 72 samples of unfilled PMMA were divided into two groups. Group 1 was subjected to a short curing cycle and group 2 to a long thermal curing cycle. Color measurements were done using a spectrophotometer and evaluated by the Commission Internationale de l'Eclairage (CIE) L*a*b* color system. Color difference (∆E) was calculated before and after thermal curing cycles and the data were statistically analyzed. RESULTS: Group 2 teeth exhibited the highest ΔE values and color change to long curing cycle with significant difference between them. CONCLUSION: All the ΔE values were below 3.3, indicating that the color changes are not clinically perceptible.

Evaluation of Stress Distribution and Force in External Hexagonal Implant: A 3-D Finite Element Analysis.

PURPOSE: To analyze the stress distribution and the direction of force in external hexagonal implant with crown in three different angulations. MATERIALS AND METHODS: A total of 60 samples of geometric models were used to analyze von Mises stress and direction of force with 0-, 5-, and 10-degree lingual tilt. Von Mises stress and force distribution were evaluated at nodes of hard bone, and finite element analysis was performed using ANSYS 12.1 software. For calculating stress distribution and force, we categorized and labeled the groups as Implant A1, Implant A2, and Implant A3, and Implant B1, Implant B2, and Implant B3 with 0-, 5-, and 10-degree lingual inclinations, respectively. Inter- and intra-group comparisons were performed using ANOVA test. A p-value of ≤0.05 was considered statistically significant. RESULTS: In all the three models, overall maximum stress was found in implant model A3 on the implant surface (86.61), and minimum was found on model A1 in hard bone (26.21). In all the three models, the direction of force along three planes was maximum in DX (0.01025) and minimum along DZ (0.002) direction with model B1. CONCLUSION: Maximum von Mises stress and the direction of force in axial direction was found at the maximum with the implant of 10 degrees angulation. Thus, it was evident that tilting of an implant influences the stress concentration and force in external hex implants.

Comparison of Primary Stability of Implants Installed by Two Different Methods in D3 and D4 Bone Types: An In Vitro Study.

OBJECTIVE: The purpose of the study is to assess the method of implant insertion in D3 and D4 bones and influence of insertion torque for achieving better primary implant stability. MATERIALS AND METHODS: A total of 32 specimens (wood blocks) simulating D4 and D3 bone were grouped into 1, 2, 3, and 4. In groups 1 and 3, the implant and abutment were placed by manual method while in groups 2 and 4 by motor-driven method. The osteotomy site was prepared as per the protocol for soft bone, and implants were placed till the implant platform was in flush with the surface of the block. After achieving a standard insertion torque of 40 N.cm, pullout test was carried out with a universal testing machine and results were analyzed by one-way analysis of variance. RESULTS: An intergroup comparison of peak loads revealed an overall statistically significant difference (P < 0.0001) with a mean of 442.638 N, maximum in group 4 and least (202.963 N) in group 1. The mean elongation break was found to be maximum in group 3 samples (81.67600%) and less in group 4 (37.15113%). Intergroup comparison of Young's modulus was statistically significant (P < 0.0001) with a mean value found to be minimum among group 1 samples (597.54750 MPa) and maximum in group 2 (1056.76463 MPa). An intergroup comparison of yield points was found to be maximum among group 4 samples (16.17238MPa) and least in group 1 (5.77438MPa). CONCLUSION: The D3 bone sample provided greater primary stability of implant than D4 bone samples, and the motor-driven implant seemed to have improved stability than that placed manually.

Oral Health-Related Quality of Life (OHRQoL) in Patients with Dental Prosthesis

Abstract Objective: To determine the Oral Health-Related Quality of Life (OHRQoL) for post-treated fixed dental prostheses in selected sample of patients. Material and Methods: 120 patients treated with fixed dental prostheses, either single crowns or fixed partial dentures in maxillary or mandibular arches were asked to express their views about their quality of life. Patients' files were randomly selected from the archives of Department of Prosthetic Dental Sciences, College of Dentistry, Jouf University, Saudi Arabia. For this purpose, a self-structured questionnaire was prepared and their responses recorded. The responses were categorized on a 5 point scale and frequencies calculated. Results: Of 120 patients approached, 79 responded with the mean age group of 37 years. From the survey, it was noted that only three variables were statistically significant, those relating to the importance of natural teeth over fixed prostheses (p=0.046), the ability to chew all kinds of foods (p=0.021) and satisfaction with the occlusion (p<0.001). Conclusion: Oral health remains important, which directly or indirectly is related to many systemic diseases. In the present study, the majority of patients were satisfied with the treatment given.