The Journal of Indian Prosthodontic Society最新文献

Aim: The precise estimation and replication of skin color are crucial for maxillofacial prosthesis. The study aimed to evaluate facial skin color with a colorimeter and suggest a skin shade guide and formula for color estimation.

Settings and design: An observational study conducted in the department of prosthodontics.

Materials and methods: Study was conducted on 368 individuals of Indian origin in age range of 20-45 years. The facial skin color was assessed in malar regions using SkinColorCatch colorimetric device and individual topography angle (ITA) and CIELAB L*a*b* values were noted.

Statistical analysis used: K-means clustering was utilized to propose a shade guide for maxillofacial prosthesis with 24 skin shades. Logistic regression analysis was conducted to propose a formula to estimate skin shade of the individuals.

Results: Based on cluster analysis, 368 subjects were divided into three clusters with similar characteristic as Cluster 1 with dark skin color in 88 (23.91%) subjects, Cluster 2 with medium skin color in 224 (60.87%) subjects, and Cluster 3 with light skin color in 56 (15.22%) subjects. The mean ITA and L*a*b* values for cluster 1 were -47.04° ±14.77°, 34.53 ± 4.31, 8.55 ± 2, 11.42 ± 3.7033, respectively. The mean ITA angle and L*a*b* values for Cluster 2 were 4.29° ±11.34° 51.67 ± 3.42, 8.79 ± 3.13, 21.36 ± 2.38, respectively. The mean ITA and L*a*b* values for Cluster 3 were 34.65 ± 4.29°, 62.66 ± 3.08, 6.53 ± 1.79, 17.73 ± 2.39, respectively. The proposed shade guide comprised a total of 24 different shades that were categorized into three primary colors according to three distinct clusters, each of which was further broken down into eight subclusters containing various shades within each cluster. Logistic regression analysis gave an equation as follows: Y =12.43 + 0.186X (Y = Predicted skin color, X = ITA angle).

Conclusions: Twenty-four facial skin shade tabs have been proposed based on ITA angle and CIELAB values. This comprehensive approach to categorize the shades will ensure a detailed and organized system for selecting and matching colors in maxillofacial prosthesis.

Statement of problem: Improvement in outcomes of obstructive sleep apnea (OSA) could answer the question of whether nocturnal wearing of removable complete dentures is beneficial.

Purpose: To evaluate the available literature that compares nocturnal wearing of removable complete dentures or overdentures in patients diagnosed with OSA on the Apnea-Hypopnea Index (AHI), Epworth Sleepiness Scale (ESS), quality of sleep (Pittsburgh Sleep Quality Index [PSQI]) and other outcomes.

Methods: Registration of the proposed protocol was done in an open-source registry. Databases (Medline, Embase, and Cochrane Central Register of Controlled Trials) were searched until August 2024. All the reports were screened by reading the abstracts and full texts by two independent reviewers and conflicts were resolved by the third reviewer in Covidence. Data extraction and risk of bias assessment as per the Risk of Bias 1.0 tool (RoB 1.0) were done in Covidence. Mean difference and risk ratios were used as effect measures for continuous and dichotomous outcomes. Statistical analysis was performed using a fixed effect model. The certainty of evidence was judged by the GRADE approach.

Results: Out of 2428 available reports, three randomized controlled trials were included for statistical analyses involving a total of 123 participants. The pooled estimate for AHI showed no evidence of any difference with and without nocturnal wear of removable complete dentures (MD: 2.88; 95% confidence interval [CI]: 0.94 to 6.70; 246 participants). No evidence of any difference was found for PSQI (MD: 0.20; 95% CI: -0.97 to 1.37; 138 participants) and for ESS (MD: 0.20; 95% CI: -1.60 to 1.20; 138 participants).

Conclusion: The review found insufficient evidence to judge that nocturnal wearing of removable complete dentures was effective in patients with OSA measured by Apnea Hypopnea Index, PSQI, and Epworth sleepiness scale.

Aim: To assess and analyze the bond strength of polymeric organic clay and heat polymerized PMMA with RTV maxillofacial silicone with and without an adhesive primer.

Settings and design: The use of polymeric clay as a substructure for implant retained maxillofacial silicone prosthesis is suggested. However, the bond strength of polymeric clay with room temperature vulcanizing (RTV) maxillofacial silicone and heat polymerized polymethyl methacrylate(PMMA) with RTV maxillofacial silicone has yet to be studied.

Materials and methods: Fifty two samples were prepared in total. Group 1 (n = 13) silicone and PMMA without primer. Group 2 (n = 13) silicone and PMMA with primer. Group 3 (n = 13) silicone and polymer clay without primer. Group 4 (n = 13) silicone and polymer clay with primer. The samples were of dimensions of 75 mm × 10 mm × 3 mm. For groups 1 and 2, samples were fabricated with PMMA over which RTV silicone was manipulated, packed and vulcanized for 24 h. For Groups 3 and 4, polymer clay was molded to the required dimensions and hardened. RTV maxillofacial silicone was manipulated and packed over it and vulcanized. For Group 2 and 4 samples, primer was applied to the uncovered part of PMMA and polymeric clay respectively. The samples were subjected to a 180° and 90° (t peel test) peel strength test, respectively.

Statistical analysis used: One way analysis of variance was used to analyze bond strength, which was then followed by a post hoc Tukey's test.

Results: The mean bond strength of silicone and PMMA without primer was 0.35 ± 0.07 mN/m, while silicone and PMMA with primer had a mean bond strength of 0.41 ± 0.04 mN/m. The mean bond strength of silicone and polymer clay without primer and silicone and polymer clay with primer was found to be 0.45 ± 0.13 mN/m and 0.30 ± 0.05 mN/m, respectively. An 80% research power and a 95% confidence interval were used in the statistical analysis. A significance threshold of P < 0.05 was applied.

Conclusion: The silicone to heat polymerized PMMA primer bond strength is the same as the silicone to polymer clay primer bond strength. Bond strength of polymer clay and maxillofacial silicone without primer is better than with primer. Therefore, without primer application, polymer clay substitutes PMMA as an interface between maxillofacial silicone material and attachments/keepers.

Aim: Since the advent of radiotherapy, the success rate of head and neck cancer treatment has increased significantly. However, when the tissue tolerance level is exceeded, unnecessary and uncontrolled exposure to radiation is considered detrimental. Such problems remain difficult to prevent and manage. The aim of the study to evaluate and compare the degree of attenuation of therapeutic radiation using four different radiation shielding materials of varying thickness.

Study setting and design: In vitro experimental study.

Materials and methods: The samples were divided into four groups based on the different radiation shielding materials of thickness 3mm and 5mm. The materials are Lead (Pb), Silver-tin alloy (Ag-Sn) with Polyvinylsiloxane (PVS), Polymethylmethacrylate (PMMA) with Barium sulphate (BaSO4), and a combination of Ag-Sn with PVS and PMMA with BaSO4 which was exposed to radiation. The radiation dose measurements were recorded and the radiation attenuation properties of the shielding materials were evaluated. Among all of the shielding materials the most efficient material under consideration is determined.

Statistical analysis used: One-way ANOVA followed by post hoc test was used to compare the means of all four groups.

Results: A statistically significant difference between groups was found by a one-way ANOVA with a P = 0.001. In the post hoc test, statistically significant findings were obtained with a P = 0.05 when comparing the variation values of 3mm and 5mm thickness between each group and other groups.

Conclusion: The shielding materials results in significant reductions in radiation dosage. It was concluded that the combinations of Ag-Sn alloy with PVS, and PMMA with BaSO4 of thickness 5 mm had a good shielding effect.

Aim: This study aimed to evaluate the effectiveness of a tailored progressive dietary intervention against the standard care instructions on the nutritional status and nutrient intake in geriatric patients receiving new complete dentures.

Settings and design: Randomized controlled trial.

Materials and methods: A randomized controlled trial was conducted on completely edentulous patients seeking complete dentures. The participants were randomly allocated into two groups, and each group received a separate set of advice. The cognitive function was assessed using the mini-mental state examination (MMSE) form. The outcome measures were assessed at the baseline and 3 months after denture insertion. The Mini Nutritional Assessment (MNA) form was used to evaluate the nutritional status and the nutrient intake was calculated by a 3-day 24-h dietary recall and fed into the DietCal software.

Statistical analysis used: The analysis was done using the independent sample t-test, paired sample t-test, and analysis of co-variance. The significance level was set at 0.05 for all tests.

Results: In total, 68 participants completed the trial. There were no significant differences in food intake between the two groups at baseline. However, at 3-month follow-up, the intervention group displayed a statistically significant improvement in body mass index (BMI) compared to the control group. Although the nutrient intake such as protein, dietary fiber, total fat, calcium, carbohydrate, energy, iron, and Vitamin B12 was higher in the intervention group than in the control group, it was not statistically significant.

Conclusion: Simple, tailored dietary intervention with prosthetic restoration of the edentulous patients significantly improved BMI and MNA scores.

Aim: The aim is to determine thermal conduction by heat-activated polymethylmethacrylate (PMMA) infiltrated with 1 weight% Titanium Dioxide (TiO2) and 1 weight% Zirconium Dioxide (ZrO2) nanoparticles and to compare with that of conventional PMMA.

Study setting and design: In vitro experimental study.

Materials and methods: Eighteen disc shaped specimens with a thickness of 5 mm and diameter of 50 mm, were fabricated and grouped according to the material used: Group B1 (resin infiltrated with 1 weight% TiO2), Group B2 (resin infiltrated with 1 weight% ZrO2), and Control Group B3 (heat-activated conventional PMMA resin). Disc-shaped specimens were analyzed for thermal conductivity using "modified guarded hot plate apparatus" in the thermal lab of the Indian Space Research Organisation.

Statistical analysis used: One-way ANOVA followed by Tukey's post hoc test was used to compare the arithmetic means of all three groups.

Results: A statistically significant difference was noted among all three groups. Group B2 had the maximum thermal conductivity, followed by Group B1. Thermal conductivity was the least for Group B3. A post hoc comparison revealed that the difference was significant between Group B2 and Group B3.

Conclusion: Nano ZrO2 addition in PMMA increased its thermal conductivity. There is evidence that it improves its mechanical properties as well. Hence, Nano ZrO2 addition in PMMA is highly recommended. Nano TiO2 addition in PMMA did not provide any significant advantage in terms of thermal conductivity, but its addition in PMMA is justified because of its mechanical and antimicrobial properties.

Aim: Synthetic inorganic materials are commonly used as reinforcing agents in polyetheretherketone (PEEK) composite, whereas natural organic plant-based reinforcing agents are negligible. Surface hardness, roughness, and wettability are indicative factors of osseointegration behavior to be used as an implant material. This study evaluated micro surface hardness (MSH), nano surface hardness (NSH), surface roughness (SR), and contact angle (CA) of PEEK-Azadirachta indica reinforced at 10 wt%, 20 wt%, and 30 wt%.

Settings and design: This was an in vitro study.

Materials and methods: Neem (A. indica) leaf nanoparticles were prepared and reinforced with PEEK powder at 10%, 20%, and 30% weight ratios by injection molding. Sixty specimens underwent the microhardness and CA testing using a digital microhardness tester, and CA goniometer, respectively, and later nanoindentation test to analyze the nanohardness and SR.

Statistical analysis used: A one-way ANOVA test with a 95% confidence interval for MSH and NSH, SR, and CA was performed on the samples. A post hoc Bonferroni test was conducted (α = 0.05) to compare the groups.

Results: There was a significant increase in nanohardness (P = 0.000) with zero difference in microhardness (P = 0.514). The addition of 10 wt%, 20 wt%, and 30 wt% nanoparticles increased the SR value of the pure PEEK from 273.19 nm to 284.10 (3.99%), 296.91 (8.68%), and 287.54 (5.24%), respectively. In the analysis of the CA, CA 20% shows the lowest angle (63.69) with the highest for control specimens (82.39). There is an increase in the PEEK composite SR with a decrease in CA.

Conclusions: The addition of plant-derived nanoparticles into the PEEK matrix has a significant impact on the hardness and hydrophobicity enhancing cell growth and osteoblastic differentiation during osseointegration of dental implants.

Aims: The aim of this study was to compare the marginal fit of prefabricated occlusal veneers with computer-aided design/computer-aided manufacturing (CAD-CAM)-milled zirconia occlusal veneers in the posterior teeth.

Settings and design: Forty extracted human maxillary premolars were divided into two groups of 20 each. Group 1 was prepared to receive prefabricated occlusal veneers, and Group 2 was prepared to receive CAD-CAM-milled zirconia occlusal veneers.

Materials and methods: Prefabricated samples (Edelweiss) were selected for Group 1, whereas for Group 2, the tooth preparations were scanned, and occlusal veneers were fabricated using Exocad designing software and milling machine. After luting, both the groups were submerged in dye, sectioned, and evaluated for marginal fit and microleakage under a stereomicroscope using the microscope imaging software and its measurement tool.

Statistical analysis used: Data collected were subjected to statistical analysis using SPSS 27.0. Intragroup and intergroup comparison was done using the Mann-Whitney U test. The Chi-square test was applied to check the depth of penetration of dye based on percentages.

Results: The marginal gap of zirconia occlusal veneers fabricated with CAD-CAM is higher compared to that of prefabricated occlusal veneers. Similarly, the depth of penetration of dye is higher in CAD-CAM-milled zirconia occlusal veneers than prefabricated occlusal veneers.

Conclusion: The marginal fit of prefabricated occlusal veneer is better than the marginal fit of zirconia occlusal veneers fabricated with CAD-CAM. Similarly, it can also be concluded that the microleakage of prefabricated occlusal veneer is less compared to the CAD-CAM-milled zirconia occlusal veneers.

Background: The orchestration of jaw relations in edentulous scenarios poses a significant challenge, demanding acumen, and expertise from the clinician. A myriad of devices, substances, and methodologies are employed to gauge the transverse, vertical, and horizontal spectrums of jaw relations. Traditionally, a synthesis of assorted devices and techniques has been requisitioned to chronicle the spatial dynamics between the maxilla and mandible. Yet, the absence of a solitary apparatus capable of concurrently documenting the triad of jaw relations has been a notable lacuna in prosthodontic rehabilitation.

Purpose: This discourse expounds on an innovative contrivance, termed the Precise Jaw Relation Recorder. This pioneering instrument is adept at capturing the tripartite jaw relation processes: the occlusal plane's alignment in parallelism to the ala-tragus line, the vertical dimension at repose, and the occlusion as well as the centric relation. The device's strategic utility lies in its ability to facilitate the creation of prostheses that are not only functionally superior but also aesthetically more pleasing.

Conclusion: Its implementation is a stride toward refining the accuracy of prosthodontic outcomes, thereby elevating the standard of patient care in dental practice.