Intricate Assessment and Evaluation of Effect of Bruxism on Long-term Survival and Failure of Dental Implants: A Comparative Study.

INTRODUCTION: Dental implants are one of the common lines of treatment used for the treatment of missing tooth. Various risk factors are responsible for the failure of the dental implants and occurrence of postoperative complications. Bruxism is one such factor responsible for the failure of the dental implants. The actual relation between bruxism and dental implants is a subject of long-term controversy. Hence, we carried out this retrospective analysis to assess the complications occurring in dental implants in patients with and without bruxism. MATERIALS AND METHODS: The present study included 1100 patients which were treated for rehabilitation by dental implant procedure at 21 dental offices of Ghaziabad (India) from 2004 to 2014. Analyzing the clinical records of the patients along with assessing the photographs of the patients was done for confirming the diagnosis of bruxism. Clinical re-evaluation of the patients, who came back for follow-up, was done to confirm the diagnosis of bruxism. Systemic questionnaires as used by previous workers were used to evaluate the patients about the self-conscience of the condition. Estimation of the mechanical complications was done only in those cases which occurred on the surfaces of the restoration of the dental implants. All the results were analyzed by Statistical Package for Social Sciences (SPSS) software. Student's t-test and Pearson's chi-square test were used to evaluate the level of significance. RESULTS: In both bruxer and non-bruxers, maximum number of dental implants was placed in anterior maxillary region. Significant difference was obtained while comparing the two groups for dimensions of the dental implants used. On comparing the total implant failed cases between bruxers and non-bruxers group, statistically significant result was obtained. Statistically significant difference was obtained while comparing the two study groups based on the health parameters, namely hypertension, diabetes, and smoking habit. CONCLUSION: Success of dental implant is significantly affected by bruxism. Special attention is required in such patients while doing treatment planning. CLINICAL SIGNIFICANCE: For the long-term clinical success and survival of dental implants in patients, special emphasis should be given on the patient's deleterious oral habits, such as bruxism as in long run, they influence the stability of dental implants.

Qualitative Assessment of Wear Resistance and Surface Hardness of Different Commercially Available Dental Porcelain: An in vitro Study.

INTRODUCTION: In an attempt to minimize wear damage to the enamel of antagonist teeth, new low and medium fusing ceramic materials have been developed. Manufacturers usually claim that these ceramics are wear-friendly because of their lower hardness, lower concentrations of crystal phase, and smaller crystal sizes. This study aimed to quantitatively analyze the wear strength of various commercially available dental porcelain with tooth enamel as well as the surface hardness of these dental porcelain. MATERIALS AND METHODS: The basic model was designed as a pin on plate arrangement. The tooth specimens were mounted on the stylus which was centered on the ceramic specimen in a wear testing machine. The dental ceramic specimen was centered in the metal die. A load of 40 N was applied at a rate of 80 cycles/minute for 15 minutes. In the current study, mean wear depth (Ra) value, volumetric loss, and surface hardness were obtained by standard quantification method and were statistically evaluated. RESULTS: Ceramco-3 was reported to be most abrasive for enamel; however, Duceram love significantly more abraded itself than the other two, Ceramco-3 and Vita Alpha, and generated the lowest loss of enamel. Also, same abrasive type of wear was revealed for all three variants of tested ceramics. CONCLUSION: Ceramco-3 was the most abrasive for enamel, while surface roughness (mean wear depth) of Duceram love was maximum and for Ceramco-3 it was minimum. The value of surface roughness for Vita Alpha was in between Duceram love and Ceramco-3. Nonetheless, the mean surface hardness of Duceram love was found to be least and maximum for Vita Alpha. CLINICAL SIGNIFICANCE: In situations of dental wear and wasting tooth disease (Attrition/Abrasion), Duceram can be applied in lieu of Ceramco-3 so as to prevent worsening of existing dentition. However, in younger patients Vita Alpha would offer maximum durability due to its greater surface hardness.

Reliability of different facial measurements for determination of vertical dimension of occlusion in edentulous using accepted facial dimensions recorded from dentulous subjects.

The study was undertaken to evaluate the reliability of different facial measurements for determination of vertical dimension of occlusion in edentulous subjects using accepted facial dimensions recorded from dentulous subjects. The hypothesis was that facial measurements can be used to obtain the vertical dimension of occlusion for edentulous patients where no pre-extraction records exist. A total of 180 subjects were selected in the age groups of 50-60 years, consisting of 75 dentate male and 75 dentate female subjects for whom different facial measurements were recorded including vertical dimension of occlusion and rest, and 15 edentulous male and 15 edentulous female subjects for whom all the facial measurements were recorded including the vertical dimension of rest and occlusion following construction of upper and lower complete dentures. The left outer canthus of eye to angle of mouth distance and the right Ear-Eye distance were found to be as valuable adjuncts in the determination of occlusal vertical dimension. The Glabella-Subnasion distance, the Pupil-Stomion distance, the Pupil-Rima Oris distance and the distance between the two Angles of the Mouth did not have a significant role in the determination of the occlusal vertical dimension. The vertical dimension can be determined with reasonable accuracy by utilizing other facial measurements for patients for whom no pre-extraction records exist.

A Comparative Evaluation of Prosthetic and Biological Outcome as Influenced by Two Different Implant Restorative Materials (Porcelain Fused to Metal and Monolith Zirconia): A Prospective, Cross-arch Study.

OBJECTIVE: To investigate the prosthetic parameters, clinical indices, crestal bone levels, and inflammatory biomarkers in peri-implant crevicular fluid as influenced by two different implant restorative materials i.e., metal ceramic and monolithic zirconia at baseline, 1 Year and 2 Years. MATERIALS AND METHODS: Twenty patients with bilateral implants placed in the same arch were selected. Monolithic zirconia (4Y-PSZ) crown was placed on one side whereas a metal ceramic (M C) crown was inserted on the contralateral side after randomization. Interproximal marginal bone level (MBL), clinical parameters, MMP-8 levels in PICF, and prosthetic characteristics (as determined by modified USPHS criteria) were evaluated at baseline, 1-year, and 2-year follow-ups. Data were descriptively examined. The results were evaluated using the Chi-Square Test, ANOVA, and student t-test. At p < .05., statistical significance was determined. RESULTS: Twenty MC crowns and twenty Mono-ZrO2 crowns were delivered. A 100% survival of the implants and the prosthetic crowns was achieved across all patients with no instances of failure noted throughout the two-year follow-up period. The periodontal changes observed in the participants were analysed and demonstrated statistically insignificant alterations. Prosthetic alterations were assessed according to USPHS criteria, revealing minor ceramic chippings and instances of screw loosening within the MC group during both the 1- and 2-year follow-up periods. These incidents were collectively categorized as technical issues. Regarding anatomical form and color match to the surrounding dentition, the Mono- ZrO2 crowns obtained much lower evaluations when compared to the M-C crowns. However, when evaluating the loss of marginal bone and level of inflammatory markers there were no discernible variations between the groups. CONCLUSIONS: The null hypothesis that there is no similarity in the survival rates and interactions at the peri-implant interface between the two types of restorations was rejected. Both monolithic zirconia and metal ceramic crowns demonstrated no statistical differences across all parameters examined in the present prospective investigation.

Evaluation of physical changes due to simulated loading on prosthetic screw supporting 4- and 6-unit implant prosthesis: An in vitro study.

Aim: Screw loosening is a very common cause of failures in implant prosthodontics. In order to avoid screw fracture, it is imperative to understand the mechanical behavior of the screw and the dynamics it is subjected to intraorally. The present study was conducted to qualitatively evaluate and compare the morphological changes, surface defects, and cracks observed under a scanning electron microscope (SEM) in the prosthetic screw. Settings and Design: Two Stainless steel edentulous mandible models were fabricated on the basis of all on four and all on six concepts by using CAD design. Screw retained prosthesis were fabricated for both the models and total number of 80 prosthetic screws were made up of Ti6Al4V. Materials and Methods: Eighty prosthetic screws (N = 80) used in four- and six-unit implant-retained cast hybrid denture were subjected to cyclic loading of 1.5 million cycles and 3 million cycles, simulating a 5 and 10 years of usage, respectively. Once the simulated cycles had been completed in all subgroups, each prosthetic screw was inspected under SEM (×150-×1000) for any changes. Statistical Analysis: The data thus obtained were statistically analyzed using SPSS 12.0 software and P < 0.005 was considered statistically significant. Results: The study revealed statistically significant (P < 0.005) changes (like morphological changes, surface defects, crack initiation, and propagation) in the prosthetic screws after exposing them to predefined test conditions (P < 0.001). Conclusion: It can be concluded that the prosthetic screws need to be changed after a period of clinical use of 5 years irrespective of the number of implants used for rehabilitation. Further, the tilt of the abutment and numbers of implants also contribute to the stresses on the implant-supported prostheses.

Evaluation and comparison of vertical marginal fit of three different types of multiunit screw-retained framework fabricated for an implant-supported prosthesis - An in vitro study.

Aim: The present study aimed to evaluate on a comparative basis the vertical marginal fit between conventionally casted, direct metal laser sintered (DMLS), and milled computer-aided design/computer-aided manufacturing (CAD-CAM) one-piece metal framework supported by five implants using one-screw test and screw resistance test. Settings and Design: This is an in vitro study. Materials and Methods: Five implants were placed parallel to one other in a Styrofoam master model. A total of 30 implant-supported screw-retained superstructures were manufactured using three techniques, i.e., conventionally casted, milled, and sintered. To evaluate the vertical marginal discrepancy, screw resistance test, and one-screw test were used, and measurements were made using a stereomicroscope. Statistical Analysis Used: The data was analysed using two statistical tests, i.e., ANOVA and the post hoc Bonferroni test. Results: On evaluating the frameworks using one-screw test, the mean vertical misfit value at the terminal implant for the control group was 292.58 ± 15.46µm, for conventionally casted framework 398.41 ± 21.13 µm, for DMLS 343.44 ± 24.73 µm, and for CAD-CAM was 304.03 ± 14.23 µm, whereas the average misfit values at four implants on applying screw resistance test were 1268.65 ± 84.24 (control), 1774.88 ± 67.70 (casted), 1508.02 ± 62.19 (DMLS), and 1367.29 ± 81.87 (CAD-CAM). The average misfit values on two implants using screw resistance test were 635.02 ± 57.33 for the control group; for conventionally casted, it was 879.75 ± 35.93; for (DMLS) framework, it was 761.51 ± 32.85; and for milled CAD-CAM framework, it was 687.07 ± 42.17 µm. Conclusion: The mean vertical marginal discrepancy, when compared with control, was least in milled CAD-CAM frameworks, followed by sintered DMLS and conventionally casted frameworks. Hence, according to the present study, CAD/CAM technique is recommended to achieve maximum marginal fit in full mouth screw-retained implant-supported FDPs.

Comparative evaluation of crestal bone levels following placement of implant in delayed implant bed: An in vivo clinical study.

BACKGROUND: Restoring lost dentition using dental implant is one of the most promising treatment modality, for both complete and partially dentulous situation. In order to have more predictable outcome, the quest for coming up with a surgical protocol has been never ending. Keeping the same in mind the present study was conducted to place implant in delayed implants beds, i.e., 14 days after the osteotomy site was prepared. MATERIALS AND METHODS: For the purpose of the study, ten implants measuring 4.2 mm × 10 mm were placed in ten healthy individuals with missing mandibular first molars in site prepared 14 days before actual placement of implants, i.e., delayed implant beds. RESULTS: The study revealed that, on evaluation of the bone levels at the time of placement of prosthetic loading revealed, a bone gain was maximum after 3 months of prosthetic loading. CONCLUSION: A significant bone gain with a mean of 0.8 mm makes this technique of placing implants in delayed implant beds a more predictable technique than conventional protocol.

An in vitro comparative evaluation between virtually planned implant positions on interactive implant software versus actual implant positions achieved using sterolithographic open guide system.

PURPOSE: To evaluate and compare the positional and angular accuracy of virtual implant positions planned on cone-beam computed tomography and final implant positions achieved using a universal open guide system. MATERIALS AND METHODS: A dual scan of a partially edentulous jaw model along with prosthesis was done, and virtual implant planning was performed. Three implant positions in relation to 35, 36, and 37 were simulated (Group A). In total, 24 implants were placed in eight replaceable bone blocks (Group B) in the same region on the model using an open stereolithographic template. The linear positions and angulation of the placed implants were determined using Vision Measuring Machine. Deviations between virtually planned and surgically placed implants were analyzed in terms of linear and angular measurements. Data were analyzed with the independent-sample t-test with differences P ≤ 0.05 being considered statistically significant. RESULTS: The linear distance (mean ± standard deviation [SD]) in mesiodistal direction between implants in relation to 35 and 36, 36 and 37, 35 and 37 in Group A was 8.79 ± 0 mm, 8.71 ± 0 mm, and 17.50 ± 0 mm, respectively, and in Group B was 7.70 ± 0.58 mm, 8.11 ± 0.30 mm, and 15.80 ± 0.48 mm. All these above values were found to be statistically significant (P ≤ 0.05). The linear distance (mean ± SD) in the vertical direction (mesial) for implants placed in the region of 35, 36, 37 for Group A was 1.51 ± 0 mm, 1.51 ± 0 mm, and 2.47 ± 0 mm, respectively, and for Group B was 1.37 ± 0.32 mm, 1.65 ± 0.48 mm, and 1.79 ± 0.36 mm, respectively. The linear distance (mean ± SD) in the vertical direction (distal) for implants placed in the region of 35, 36, 37 for Group A was 3.37 ± 0 mm, 1.51 ± 0 mm, and 1.51 ± 0 mm, respectively, and for Group B was 1.86 ± 0.48 mm (P ≤ 0.05), 1.56 ± 0.23 mm, and 1.29 ± 0.39 mm (P ≤ 0.05), respectively. The angular deviation (perpendicularity) values for virtually planned implants (Group A) were 90.00° ± 0° and for implants placed in the region of 35, 36, and 37 (Group B) were 84.52° ± 5.4°, 83.57° ± 1.52°, and 80.41° ± 2.37°, respectively, which are highly significant (P ≤ 0.05). CONCLUSIONS: The stereolithographic universal open guide used in the study may be considered accurate for placement of implants in mesiodistal position and also in terms of perpendicularity but not in the vertical position. Stereolithographic open guide may be recommended for more accurate implant position, especially for the placement of multiple implants.

Spectrophotometric evaluation of the color changes of different feldspathic porcelains after exposure to commonly consumed beverages.

OBJECTIVE: The aim of this study was to compare color stability and surface topography of three different feldspathic porcelains both qualitatively and quantitatively after exposure to routinely consumed beverages over different time periods using a Spectrophotometer, Stereomicroscope and Surface roughness tester, respectively. MATERIALS AND METHODS: A total of 90 plastic discs were casted to obtain metal dies for three different newer ceramic applications each on thirty samples. The color and surface roughness of these samples were measured using stereomicroscope and surface roughness tester following which they were kept in different test solutions for different durations and revaluated for color changes and surface roughness in the similar manner. RESULTS AND CONCLUSION: Among all the five test solutions, Coffee showed the maximum staining of the ceramic whereas maximum surface roughness was shown by the Duceram Kiss (1.48 µm) by Orange Juice which could be due to its high titratable acidity.