The Journal of Indian Prosthodontic Society最新文献

Aim: The aim is to evaluate and compare stress distribution characteristics of ball, magnet, and positioned attachment systems in single and double implant-retained overdentures using the finite element method (FEM).

Setting and design: In vitro (in silico study) finite element analysis (FEA).

Materials and methods: A Styrofoam mandible with duplicated silicon mucosa was used to construct a mandibular complete denture. Implants of size 12 mm by 3.4 mm body diameter (Implantium, Dentium, Korea) were used along with ball O-ring, positioner, and magnet attachment system for constructing single and double implant overdenture. FEA models were processed defining geometry. Six models were formulated, namely, three models of central single implant and three for double implant overdenture using ball O-ring attachment, positioner attachment, and magnet attachment named B1, P1, M1, B2, P2, and M2, respectively. The FEM analysis was done using ANSYS workbench 16.0. A load of around 100N was applied bilaterally in the first molar regions, anteriorly between the two central incisors, and unilaterally on the right first molar region. Stresses were calculated according to the Von Mises stresses scale. Stress magnitude and patterns were analyzed and interpreted accordingly.

Statistical analysis used: Stress patterns and maximum principal stress were described.

Results: FEM analysis revealed that stress concentration in the B1 model was the highest. Anterior loading produced maximum stress followed by unilateral and lastly bilateral loading. In the bone, stress concentration was the highest in the crestal bone region (3-18 MPa). Mucosa showed the least amount of stress in all models (1.3-3 MPa). Stress patterns in dentures were symmetric with concentration on the mid-lingual and molar premolar area (3-18 MPa). Implants showed stress concentration near the collar and the internal connection region (7.5-24 MPa). Maximum stresses were around the head of prosthetic abutments (10.5-24 MPa). The stress concentration in the ball head was typically located in the abutment neck. In positioner attachment, stress was located in the inner open end area (11-20.1 MPa). For the keeper, stresses were at its base and stress patterns extended into the body (10.5-17.7 MPa). Less stress magnitude was seen for all models on bilateral loading (10.5-15 MPa).

Conclusion: Magnet and positioner attachments have a more favorable stress distribution in both single and double implant-retained overdentures. Bilateral loading conditions are more favorable for uniform stress patterns.

Aim: The aim of this study was to investigate and compare the antimicrobial effects of an 810-nanometer diode laser, utilizing or not utilizing toluidine blue as a photosensitizer, in the management of peri-implant mucositis.

Settings and design: The present study was carried out in 30 implant sites in 15 patients with peri-implant mucositis with a specific inclusion and exclusion criteria. 15 sites were treated utilizing a diode laser (control group) and 15 with photodynamic therapy (test group) in a split-mouth format.

Materials and methods: Samples were taken from the gingival sulcus with the help of plastic curettes from control and test sites both at baseline and at 3 months for microbiological analysis.

Statistical analysis used: Shapiro-Wilk Test was used to check deviation from normality. Wilcoxon signed-rank test was used to analyse the two dependent groups.

Results: Intragroup comparison was found to be statistically significant when compared at baseline and at 3 months in the photodynamic (P = 0.001) and diode laser groups (P = 0.001), respectively. No statistically significant reduction in bacterial count was found at baseline (P = 0.1) and at 3 months (P = 0.5) when the diode laser group and photodynamic group were compared with each other (intergroup).

Conclusion: Within the limitations of the study, it can be concluded that there is a definitive reduction in pathogenic bacteria with both interventions and PDT offers clinically visible benefits in the treatment of peri-implant mucositis.

Aim: Aberrative occlusal contacts were associated with Temporomandibular disorder (TMD), but whether stabilization splints with therapeutic exercises alleviate the symptoms is unclear. Hence, this study aims to compare the short-term efficacy of occlusal splint therapy and the synergistic effect of therapeutic exercise with occlusal splint therapy for 3 weeks in individuals with TMD.

Settings and design: in-vivo observational pilot study.

Materials and methods: Fourteen participants were grouped based on the type of treatment: Group A, assigned with combination therapy, stabilization splint with therapeutic exercises, and Group B, with only stabilization splint therapy. Surface electromyography (EMG) was taken to evaluate the masseter and temporalis muscle activity at baseline and 2nd week. The patient's perception of TMD was evaluated using the Fonseca questionnaire at baseline, 48 h, 14th, and 21st days.

Statistical analysis: Chi-square statistical analysis was applied to the quantitative data obtained from the Fonseca questionnaire and EMG analysis, with P < 0.05 as significant.

Results: Fonseca questionnaire revealed a significant difference between the two groups at 48 h (P < 0.05). EMG outcome showed no significant difference between the groups at baseline and 14th day (P > 0.05). However, the mean muscle activity recorded at the masseter in Group B was increased on 14th day (56.5 ± 3 μV) and an isotonic muscle pattern was observed in Group A.

Conclusion: Combination therapy, which included stabilization splint and home care exercises for moderate to severe TMD patients, led to earlier curative changes in the temporomandibular joint and improved functional jaw movements, along with a reduction in pain. An isotonic muscle activity pattern was also observed, confirming the effect of combination therapy.

Aim: This study aimed to evaluate the effect of partially edentulous ()PED condition on lung function through spirometry tests and comparison of airflow rates between dentulous and PED subjects.

Settings and design: The study design was a cross-sectional study conducted in the department of prosthodontics.

Materials and methods: Twenty-eight dentulous and 28 PED patients with an age range of 25-50 years were included in the study. Patients with missing more than 3 posterior teeth were considered PED. All have undergone spirometric evaluation.

Statistical analysis used: Independent t-test was used.

Results: In all three spirometric measures (forced vital capacity [FVC], forced expiratory volume in 1 s [FEV1], and peak expiratory flow rate [PEFR]), the PED participants had significantly lower FVC, FEV1 (P = 0.0005), and PEFR (P = 0.032) airflow rates than dentulous participants, and males had higher airflow rates than females.

Conclusions: FVC, FEV1, and PEFR airflow rates were lower in PED individuals. The lower airflow rates could suggest the possible tendency to develop chronic obstructive pulmonary disease (COPD).

Aims: To assess the role of oral health literacy (OHL) in demand for oral healthcare services for missing teeth replacement among adult patients who are visiting the outpatient department of a teaching hospital, Andhra Pradesh, India.

Settings and design: This cross-sectional study was conducted in a dental teaching institute, Andhra Pradesh, southern part of India.

Materials and methods: Based on the inclusion and exclusion criteria, a sample of adult participants was selected through systematic random method from the patients who visited the outpatient department. Data from 740 participants were included in the final analysis. A prevalidated questionnaire adopted from Oral Health Literacy Adult Questionnaire (OHL-AQ) was used for data collection and american dental association (ADA) type IV clinical examination was used for recording missing teeth.

Statistical analysis used: Bivariate tests such as the Chi-square test, Mann-Whitney's test, and multinomial logistic regression analysis were used to assess the predictors for the demand for the replacement of missing teeth.

Results: The overall demand for replacement of missing teeth was 46.22%. 37.88% of participants had adequate OHL, 24.72% had marginal OHL, and 37.4% had inadequate OHL. Demand for replacement was more in females than males (57.6% vs. 35.6%), which was statistically significant (P = 0.00). Participants with missing anterior teeth had nearly twice the demand for prosthodontic care (P = 0.046). Participants with adequate OHL had 3.63 times more demand for prosthodontic replacement of missing teeth (odds ratio = 3.63 and P = 0.002).

Conclusion: OHL has a positive role in the demand for prosthodontic replacement of missing teeth along with gender and anterior missing teeth. Oral health policies should incorporate strategies to improve OHL.

Aims: To compare the accuracy of marginal fit of CAD-CAM endocrown with two different preparation forms, i.e., endocrown with ferrule and endocrown without ferrule.

Settings and design: Various studies have opined on the impact of preparation form on the marginal fit of endocrown, but studies on the effect on the marginal fit of digitally milled endocrown with and without ferrule are sparse.

Materials and methods: Total of 30 typodont were sectioned 3 mm above the cemento-enamel junction, and central cavity was prepared to depict a severely destructed tooth. The typodonts were divided into two groups: Group 1 contained specimens for endocrown without ferrule (WoF); Group 2 contained specimens for endocrown with ferrule (WF). The typodonts were prepared based on standard preparation. The specimens were then scanned using intraoral scanner, and the stereolithography (STL) was generated. Endocrowns were designed in the Exocad software using a digital library. The STL file format is translated into millable data file format (CNC- Computer numerical control) in the inLAB MC X5 Milling machine. The marginal fit of endocrowns was then assessed in the stereomicroscope.

Statistical analysis: The data was analysed with a digital image analyser. The result was generated using a two-way ANOVA test. The significance level was set at P ≤ 0.05.

Results: In the present study, the marginal fit of WoF showed a superior marginal fit than WF. A statistically significant difference was seen in the marginal fit of two endocrowns, with a higher marginal discrepancy observed in the endocrown with the ferrule. The P value for the difference in the means of the marginal gap without and with ferrule (-13.42) is zero. Maximum marginal gap of 96 micron is observed for with ferrule (WF) design at location B. Minimum marginal gap of 29 micron is observed for without ferrule (WoF) at location D.

Conclusions: Endocrown without a ferrule can provide a better marginal fit and can contribute to the long-term survival of restoration.

Aim: The purpose of this in vitro study was to compare the marginal fit of various three-dimensional (3D) printed and milled polymethylmethacrylate (PMMA) dental prostheses.

Settings and design: The study was conducted in an in vitro study setting.

Materials and methods: With a sample size of 45 for each fabrication method, this investigation compared the marginal fit of milled (Group 1) and 3D printed (Group 2) PMMA dental prostheses across different designs. The selection of samples was based on G*Power calculations. Tooth preparations were conducted on a typodont jaw set, followed by digital scanning and design processes. Computer-aided design and computer-aided manufacturing milling and 3D printing were employed for the fabrication of prostheses. The assessment of marginal accuracy at specific points was performed using a stereomicroscope.

Statistical analysis used: Independent t-tests were used to evaluate marginal discrepancies between milled and printed prosthetic designs at specific tooth surfaces. Univariate analysis of variance assessed marginal discrepancies across prosthesis designs and fabrication methods, with the Tukey post hoc test for significantly different results (α =0.05).

Results: Milled single crowns exhibited superior accuracy (61.50 ± 4.852 μ) compared to printed ones (65.74 ± 7.311 μ) (t = -1.868, P = 0.037). Similar trends were observed for other designs, emphasizing the impact of both prosthesis design and fabrication method on marginal fit. Notable discrepancies were found on the distal surfaces of the anterior bridge crossing midline design (t = -3.262, P = 0.003).

Conclusion: Milled prostheses exhibited superior marginal fit as compared to 3D printed prostheses, with differences within clinically acceptable limits.

Aim: The aim of this study was to compare the marginal accuracy of polyetheretherketone (PEEK) and zirconia copings fabricated using computer-aided design/computer-aided manufacturing (CAD/CAM) technology, and to assess the impact of their material properties on accuracy when produced with a 4-axis milling system under controlled conditions.

Settings and design: The study employed an in vitro design with a stainless steel die model featuring a 6 mm axial wall height, a 6-degree total occlusal convergence, and a radial shoulder finish line.

Materials and methods: Thirty stone dies were created from silicone impressions of the metal die and poured using type-IV dental stone. The dies were divided into two groups: Group-A (PEEK) copings and Group-B (zirconia) copings. All copings were fabricated using a CAD/CAM system. Vertical marginal accuracy was assessed with a stereomicroscope and image analysis software at ×20 magnification. The marginal gaP values were subjected to a student (independent) t-test for statistical analysis.

Statistical analysis used: The statistical analysis involved a student (independent) t-test to compare the marginal gaP values between Group A (PEEK) and Group B (zirconia).

Results: The mean marginal discrepancy for Group A (PEEK) and Group B (zirconia) was 92.84 μm ± 3.48 μm and 63.12 μm ± 31.47 μm, respectively. A statistically significant variation (t = 3.635, P = 0.001) between the groups was observed, indicating better marginal accuracy with zirconia copings compared to PEEK copings.

Conclusion: Both PEEK and zirconia copings demonstrated vertical marginal discrepancies within the clinically acceptable limit of <120 μm. However, zirconia copings exhibited superior marginal accuracy in this in vitro study.

Prosthetic rehabilitation in multifaceted dental abnormality needs sequential planning to ensure adaptation of oral and associated musculature. Reduction of tooth structure before adaptation of oral and associated components may complicate the treatment modality if compliance of the musculature is poor. Hence, the fabrication of over-provisional in esthetic rehabilitation enables to assess of the success of the treatment plan preoperatively before invasive trials. A 55-year-old male with a diagnosis of Category I loss of vertical dimension, according to Turner and Missirlian classification, required full mouth rehabilitation. The case report depicts the preoperative management of full mouth rehabilitation with direct chair-side technique using over-provisional to analyze the esthetic and functional changes. Restoration of esthetics is a complex task that needs patient satisfaction to achieve success. Over-provisional is a simplified method of establishing esthetics and functional rehabilitation. Esthetic and functional rehabilitation of an individual can be an easy transition when preoperative evaluation of the final prosthesis design is visually created intraorally.