The Journal of Indian Prosthodontic Society最新文献

Aim: The aim of this study was to evaluate and compare the effect of plasma nitride-treated abutment screws of two different implant systems on screw loosening and surface topography with and without thermocycling.

Settings and design: This was an in-vitro experimental study.

Materials and methods: Fifty-two abutment screws (Group A: 26 Genesis and Group B: 26 Bredent) underwent plasma nitride treatment and were subdivided into two groups, one without thermocycling and one with thermocycling. Dynamic load was applied and detorque values were evaluated for determining the screw loosening using "independent t-test" with the help of IBM SPSS Statistics 20 and scanning electron microscopy was done to check for surface topography.

Statistical analysis used: Inter- and intragroup comparisons were done using independent t-test (SPSS: Statistical Package for the Social Sciences software version 20).

Results: Plasma nitriding treatment genesis implant system abutment screw showed more screw loosening (P < 0.05) and surface roughness as compared to bredent with and without thermocycling.

Conclusion: From the present study, it was shown that plasma nitride-treated abutment screws decreased the occurrence of screw loosening favoring the bredent implant-abutment system more than the genesis implant-abutment system.

Aim: The aim was to compare the efficacy of various herbal disinfectants on irreversible hydrocolloid impressions and to investigate the effectiveness of three herbal disinfectants and a chemical disinfectant against particular pathogens.

Settings and design: In vitro -a comparative study.

Materials and methods: The following methodology was followed to achieve the objectives. Four maxillary impressions were made for each selected patient with irreversible hydrocolloid impression material. The predisinfection swabs were taken from impression sites of teeth 17, 13, 27, and 23 (FDI system of tooth numbering). The impressions were immersed in all four different disinfectants such as 2% glutaraldehyde, Aloe vera solution, 50% neem oil, and apple vinegar solution, then the postdisinfection swabs were taken from the same sites 17,13,27,23 and then cultured onto sheep blood agar and examined for growth, and colony forming units (CFUs) of Streptococcus viridans, Streptococcus mutans, Streptococcus sanguis, and Actinomyces viscosus. The comparative analysis was done for the predisinfection and postdisinfection values in each study group.

Statistical analysis used: Descriptive analysis, Kruskal Wallis test, Mann Whitney post hoc test, Wilcoxon signed rank test.

Results: The results revealed that the mean CFUs of S. viridans, S. mutans, S. sanguis, and A. viscosus during postdisinfection samples were statistically significant when compared to predisinfection samples. Multiple comparison of the mean CFUs of all 4 microorganisms in the control group and in 50% Neem oil group was significantly lesser compared to A. vera and Apple Vinegar group.

Conclusion: CFUs of S. viridans, S. mutans, S. sanguis, and A. viscosus significantly decreased in the 50% neem oil group as well as the control group. As a result, 50% Neem oil was a viable option for disinfecting alginate impressions.

Aims: The study aimed to evaluate biological, mechanical, and patient reported parameters associated with ASC abutments and MU abutments for the fabrication of screw retained implant crowns in the anterior esthetic zone.

Setting and design: For the study, 20 patients were selected and implants were placed within the constraints of prosthetic envelope. Later, the screw retained crown was fabricated.

Materials and methods: Biological parameters (including implant survival rate, marginal bone levels using cone beam computed tomography, and soft tissue assessment using periodontal indices) were measured at the time of crown placement and 1 year follow up. Mechanical parameter (screw loosening) was calculated using removal torque loss (RTL) values obtained at the time of crown placement and 1 year follow up. Patient reported parameters were evaluated using a questionnaire at 1 year follow up.

Statistical analysis used: All data were tabulated, statistically analyzed, and compared using SPSS version 23 IBM Corporation, Armonk, NY, USA.

Results: Implant survival was found 100% in both the groups. The marginal bone level reduced considerably in both the groups from baseline to 1 year follow up. The MU abutment group had slightly less marginal bone loss than the ASC abutment group. Additionally, there was no statistically significant difference between the two groups' periodontal indices at baseline and 1-year follow-up values. At baseline, the RTL value was substantially lower (P <0.003) in the ASC abutment group than in the MU abutment group, however at the 1-year follow-up, there was no statistically significant difference in RTL or screw loosening between the two groups. Patient-reported data showed no statistically significant difference.

Conclusion: Within the constraints of this study, it was suggested that both ASC and MU abutments provide equally promising results in terms of biological, mechanical, and patient-reported parameters in the anterior esthetic region for single screw-retained crowns.

The prosthodontics preclinical training modules involve textbook-based two-dimensional (2D) ideal images and practicing on manikin models to emulate ideal tooth preparations and teeth arrangements. Relying solely on 2D images as objectives for preclinical exercises limits the trainee's creative skills to instructions of textbooks and clinical instructions received. With advancements in digital dentistry, dental trainees should have early exposure to the three-dimensional (3D) rendering of ideal preclinical objectives. A dental education technique using computer-aided design software and smartphones is described that will allow 3D rendering of ideal prosthodontic training assignments allowing early exposure to digital dentistry for dental training students.

Temporomandibular joint disorders (TMDs) following tooth loss may or may not be prevalent, but the risk of developing these disorders is always there due to changes in occlusion and vertical dimension, leading to changes in the disc-fossa relationship. The purpose of this systematic review was to evaluate the prevalence and severity of temporomandibular joint (TMJ) disorder in partially versus completely edentulous patients. An elaborated literature search was conducted in PubMed/Medline, Scopus, Web of Science, Lilacs, and Google Scholar databases including all articles about varied effects of partial and complete edentulism on the TMJ published from January 1, 2000, to January 1, 2022. After the meticulous screening, only publications which fulfilled the inclusion parameters were ultimately selected for full-text evaluation and tested for bias using the Joana Briggs Institute Appraisal tools for cross-sectional, case-control, and cohort studies. A total of 547 articles from various electronic databases and manual searches were found. After eliminating the duplicates and thorough screening, 13 studies were included for qualitative synthesis. Most of the studies demonstrated at least one or two signs of the presence of TMDs following tooth loss, the intensity/frequency of which increased in proportion to the number of missing teeth.

Context: To promote better biological response and osseointegration continuous research is going on to modify the titanium (Ti) implant surface for successful implant treatment modality.

Aims: This study aims to evaluate the osteogenic cell growth upon the uncoated Ti discs and boron nitride (BN) coated Ti to assess osseointegration and clinical success of dental implants.

Settings and design: This is an descriptive experimental study which includes coating of uncoated titanium alloy suraface with boron nitride in the form of hexagonal boron nitride sheets. Than comparative evaluation of osteogenic cell growth upon both coated and uncoated titanium surfaces was done using specific cell growth determinants.

Materials and methods: In this descriptive experimental study, both BN-coated and uncoated Ti discs were assessed for osteogenic cell growth using 3-(4, 5-dimethyl thiazolyl-2)-2, 5-diphenyltetrazolium bromide assay, 4',6-diamidino-2-phenylindole, is a fluorescent stain assay, and cell adhesion assay.

Statistical analysis used: As this study is a descriptive experimental analysis between two variables only so there is no need of statistical analysis or p-value.

Results: Overall good cell adhesion, cell differentiation, and cell proliferation occurred in the BN-coated Ti discs as compared to uncoated Ti discs.

Conclusions: To promote osseointegration of dental implants, surface coating with BN proved to be an effective approach toward better osseointegration and long-duration success of dental implants as a single unit or implant-supported prosthesis BN which is a biocompatible graphene material with advantages in chemical and thermal stability. BN promoted better osteogenic cell adhesion, differentiation, and proliferation. Hence, it can be used as a new promising Ti implant surface-coating material.

Aim: Polymethylmethacrylate (PMMA) resin is the most by and large used denture base material. Denture fractures are sequential to the flexure or impacting forces. Different nanoparticles such as titanium dioxide and silver nanoparticles have been used to improve its antimicrobial properties. There are limited data on their effect on flexural strength. The aim of the study was to assess the effect of silver nanoparticles and titanium dioxide nanoparticles addition on flexural strength of PMMA resins.

Settings and design: One hundred and thirty specimens divided into four groups: Control Group A, TiO₂-reinforced Group B, silver nanoparticles reinforced Group C, and mixture of TiO₂ and silver nanoparticle reinforced Group D. Each reinforced group further divided based on concentrations -0.5%, 1%, 2%, and 3%.

Materials and methods: Rectangular metal models of the American Dental Association (ADA)- specified dimensions: 65 mm × 10 mm × 3 mm were used to form a mold space for the fabrication of specimens. Three-point bend test was used to determine the flexural strength of the samples after immersion in distilled water for 2 weeks.

Statistical analysis: The data collected were subjected to analysis of variance followed by post hoc Tukey's test.

Results: The comparison of the mean flexural strengths showed a statistically significant gradual decrease on increasing the concentrations of nanoparticles. Maximal flexural strength was seen in the control group and least with 3% Ag + TiO₂ Nps. The modified specimen also showed color changes.

Conclusions: In an in vitro environment, addition of TiO₂ and silver decreases the flexural strength of the PMMA. It also causes visible color changes.

Aim: The main purpose was to evaluate the effect of complete denture rehabilitation on the jaw growth pattern in individuals with ectodermal dysplasia from an early age to maturity.

Settings and design: This was a prospective in vivo study performed in the Department of Prosthodontics, King George Medical University, Lucknow, India.

Materials and methods: Rehabilitation with three sets of conventional complete dentures was completed in an ectodermal dysplasia case at the age of 5, 10, and 17 years. Cephalometric and diagnostic cast analyses were the methods performed to evaluate jaw growth patterns. Linear and angular measurements obtained after denture rehabilitation were averaged and compared with mean standard values of nearly corresponding ages, as given by Sakamoto and Bolton. Conversely, alveolar ridge arch width and length were evaluated for their dimensional changes during the same age intervals.

Statistical analysis used: Mann-Whitney U-test was used to check the difference between the groups. The significance of the level adopted was 5%.

Results: Nasion-anterior nasal spine, anterior nasal spine-menton, anterior nasal spine-pterygomaxillary fissure, gonion-sella, and gonion-menton lengths were found to be not statistically significant than the mean standard values of nearly corresponding ages (P > 0.05). The decrease in facial plane angle, increase in Y-axis angle, and mandibular plane angle after complete denture rehabilitation were statistically significant when compared to their mean standard values (P < 0.05). Cast analysis showed more increase in the length compared to the width in both arches.

Conclusion: Complete denture rehabilitation did not significantly affect the jaw growth pattern, although it improved facial esthetics and masticatory activity by establishing adequate vertical dimensions.

Aims: This study aimed to determine the association of stress and salivary cortisol levels in the adult Indian population with and without temporomandibular disorder (TMD) and to validate it with bite force.

Settings and design: The present study had an observational, case-control study design.

Materials and methods: This study sample comprised two groups of 25 cases and 25 controls between 18 and 45 years of age. Diagnostic criteria-TMD questionnaire Axis I was used to assess TMD classification, the TMD Disability Index and modified Perceived Stress Scale (PSS) questionnaires were filled, and salivary cortisol levels were measured using electrochemiluminescence immunoassay (ECLIA). Bite force analysis was performed using a portable load indicator.

Statistical analysis used: To characterize and analyze the study variables, means, standard deviations, Mann-Whitney U-test, and logistic regression were employed (STATA 14.2 [Texas, USA]). Shapiro-Wilk test was used to test the normality of the data. P < 0.05 was considered statistically significant (95% power).

Results: Female gender was proportionately higher in both the groups (P = 0.508), TMD Disability Index was significantly higher for cases (P < 0.001), TMD cases perceived higher stress levels (P = 0.011), there was no statistically significant difference in salivary cortisol level between cases and controls (P = 0.648), and the median bite force was lower for cases (P = 0.0007).

Conclusions: This study concluded that the chance of developing TMD increased with age. An increase in the TMD Disability Index score and modified PSS scores; and a decrease in the bite force increased the likelihood of TMD. Modified PSS score was negatively correlated with salivary cortisol concentrations, indicating a two-way response to TMD symptoms.

Aim: To compare the effect of polymerization of resin-modified glass ionomer cement and dual-cure resin cement on the crystalline structure and to correlate it clinically with postoperative sensitivity.

Settings and design: The evaluation of crystalline strain in the dentin slabs was done using Synchrotron X-ray diffraction. The post operative sensitivity was measured clinically using Schiff's sensitivity scale.

Materials and methods: A total of 44 extracted and noncarious premolars were collected. Dentin slabs of dimensions 2 mm × 2 mm × 1.5 mm were prepared from the buccal aspect of the extracted teeth. The dentin slabs were then divided into two groups, Group A dual-cured resin cement and Group B resin-modified glass ionomer cement was applied. The dentin slabs first underwent synchrotron X-ray diffraction before and after the application of cement. Forty-two patients who were undergoing complete metal fixed prostheses on vital posterior abutments were selected. In this, 21 vital abutments were included in each group. Tooth preparation and fabrication of complete metal prostheses were done in the conventional manner and cemented using the 2 luting cements in Groups A and B, respectively. Dentinal hypersensitivity was measured using Schiff 's scale, postcementation, after 1 week and 1 month.

Statistical analysis: Independent t-test was done for comparing the two cements in two cements in terms of lattice strain. Mann-Whitney U-test was done for comparing the cements with respect to dentinal hypersensitivity. Spearman's correlation coefficient was used for clinical correlation between dentinal hypersensitivity and crystalline strain.

Results: The lattice strain generated in dual cure resin cement was higher than that in resin-modified glass ionomer cement and was statistically significant. Postcementation hypersensitivity was higher in dual-cured resin than resin-modified glass ionomer cement but was not statistically significant in the follow-up visits. Spearman's correlation coefficients did not reveal any significant clinical correlation between lattice strain and dentinal hypersensitivity.

Conclusion: Dual cure resin cements generate greater lattice strain as compared to resin modified glass ionomer cements.