The Journal of Indian Prosthodontic Society最新文献

Aim: Facial imaging technology has become a pivotal tool in modern medical practice, particularly within fields such as maxillofacial prosthodontics, orthodontics, and smile design. The creation of digital twins, or virtual patients, enhances diagnostic accuracy, aids in treatment planning, and improves outcome prediction. The aim of the study was to assess the accuracy of various facial scanners, determine overall accuracy of each scanner, and identify which scanner demonstrates superior accuracy in specific facial regions.

Settings and design: An observational crossover study.

Materials and methods: Cone beam computed tomography volumetric scan was used as a control group, as it has been considered as a gold standard in terms of accuracy. For comparison, scan data were obtained from three different scanners, namely Carestream facial scanner, Medit intraoral scanner for facial scan, and MetiSmile face scanner. The standard tessellation language files thus obtained were compared for accuracy in Geomagic X software by superimposition technique and were evaluated for their accuracy using various reference points on the face.

Statistical analysis used: Normality was confirmed using the Shapiro-Wilk test. One-way analysis of variance for comparison among groups and Tukey test for pairwise comparison was used using SPSS software (IBM SPSS version 29 USA).

Results: The study concluded that MetiSmile was the best facial scanner among the three groups with a mean discrepancy of (0.35 ± 0.33) mm and P = 0.001, indicating significant difference between the scanners.

Conclusion: Each scanner evaluated demonstrated acceptable performance, with notable variations attributable to their distinct scanning methodologies. Among these, the MetiSmile scanner emerged as the most accurate, delivering the most favorable results in terms of accuracy.

Aim: This study delves into how different printing orientations following polishing and coating affect surface roughness and color stability, aiming to refine fabrication methods and enhance patient satisfaction.

Study setting and design: Twenty-seven polymethyl methacrylate (PMMA) resin samples were designed with dimensions of 10 mm × 2 mm and were 3D printed with three different printing orientations (0°, 45°, and 90°), followed by support removal and polishing. After the evaluation, the samples were coated with the layer of PMMA resin.

Materials and methods: Standard tessellation language files as the basis for sample preparation were generated using the Autodesk Meshmixer software and exported to 3D printer for the AM of the specimens. The samples underwent assessment for surface roughness and color stability, forming the three groups with different printing orientations. Subsequently, each sample was coated with unpolymerized PMMA resin and polymerized with ultraviolet light, forming the other three groups following coating. After this process, the samples were reevaluated for surface properties, forming the basis of the study's six distinct groups.

Statistical analyses used: The data was tabulated and evaluated for the mean and the standard deviation.

Results: Upon statistical analysis, the surface roughness of 3D printed polished PMMA resin polished and coated PMMA resin for all printing orientations (P < 0.001). The surface roughness was highest at a 45° angle, followed by 90°, with the lowest roughness observed at 0°. Similarly, in polished and coated PMMA resin, roughness was significantly higher at 45° compared to 0° and 90° but no significant difference between 0° and 90° (P > 0.05). For the color stability parameter, color change (∆E) values showed no significant difference for the three printing orientations (P > 0.05) and among the six study groups.

Conclusions: Different printing orientation markedly affects surface roughness and color stability, while coating with PMMA resin had significantly reduced the surface roughness without a significant impact on color stability. Thus, meticulous selection of printing orientation is essential for achieving desired surface properties.

Accurately replicating the peri-implant and pontic site soft tissues in a master cast is essential for achieving optimal contours in an implant-supported prosthesis. An implant cast with soft tissue replication allows for seamless integration of the prosthesis with the natural oral anatomy, resulting in an ideal emergence profile and improved esthetics. Furthermore, it encourages proper oral hygiene, leading to improved overall gingival health. A flexible gingival mask is used for this purpose. There are well-established methods for fabricating these masks on dental stone casts in an analog method. On the other hand, there is only one method currently being used to fabricate gingival masks on three-dimensional (3D) printed implant casts, which is both labor intensive and time consuming. Therefore, the purpose of this article is to provide a quicker and more effective method for creating gingival masks for 3D printed implant casts.

Aim: The aim of this study was to compare the improvement of pain between a digitally constructed stabilization splint (SS) and anterior repositioning splint (ARS) for patients with anterior disc displacement with reduction (DDWR).

Settings and design: The trial was a cross-over randomized control trial.

Materials and methods: Twenty patients were diagnosed using magnetic resonance imaging to have anterior disc displacement were included in the following trial. All included patients met the inclusion criteria and they were all suffering from pain and were classified as anterior DDWR. They were randomized using the sealed envelopes into two groups. Group A patients received ARS for 3 months and then SS for another 3 months after a 14-day wash out period, while in group B patients received SS for 3 months and then ARS for another 3 months after a wash out period of 14 days. All included patients received a primary impression followed by a centric relation record and a protrusive record for the fabrication of the splints. All splints were designed and then printed. Pain was evaluated using the Visual Analog Scale (VAS), an easy subjective proportion of pain intensity using a scale from 0 to 10, where 0 indicates no pain and 10 indicates high intensity.

Statistical analysis used: An independent t-test was performed for both groups at each fixed time interval.

Results: There was a statistically significant difference within absolute change in pain reduction for both groups over the 3-month follow-up period. During the 1st week, Group B showed a greater pain reduction compared to Group A (0.43 vs. 0.32, respectively; P = 0.0001). However, at the 2nd week, 1 month, 2 months, and 3 months, Group A demonstrated greater pain reduction than Group B, with the values of (0.87, 1.5, 1.54, and 1.82) for Group A and (0.81, 1.19, 1.43, and 1.78) for Group B, respectively (P = 0.0001).

Conclusion: Within the limitations of this study, both splints are considered reliable treatment options for patients with anterior disc displacement. The ARS initially demonstrated a greater improvement in pain compared to the SS. However, after the 3-month follow-up period, no significant difference was observed between the two splints.

Aim: The aim of the study was to investigate and compare the prosthetic parameters, clinical indices, and survival rates of two digitally fabricated extracoronal restorations, namely an onlay and a full crown, at baseline, 1 year, and 2 years.

Settings and design: This was a prospective clinical study conducted on endodontically treated posterior teeth.

Materials and methods: Endodontically treated posterior teeth (n = 15) present bilaterally in the mandibular arch were selected. Digitally fabricated lithium disilicate onlay and crown were placed on either side of the same arch after randomization. Clinical parameters and prosthetic characteristics (as per the modified United States Public Health Service criteria) were evaluated at baseline, 1-year, and 2-year follow-ups.

Statistical analysis used: Data were descriptively examined. The results were evaluated using the Chi-square test and ANOVA. Statistical significance was determined at P < 0.05.

Results: Full crowns showed a 100% survival rate, while onlays had an 83.3% survival rate, with a significant difference (P = 0.030, 95% confidence interval: 0.01-0.12). Onlays exhibited significantly better periodontal outcomes, including lower bleeding on probing (P = 0.000), plaque index (P = 0.001), and probing pocket depth (P = 0.000) at 1 and 2 years. Marginal discoloration (20%) and marginal integrity loss (13.3%) were observed in onlays, with significant differences (P = 0.001). Both groups showed no fractures, secondary caries, or significant surface texture changes, and 100% patient satisfaction throughout.

Conclusion: In this clinical trial comparing lithium disilicate onlays and crowns for restoring posterior teeth following endodontic treatment, both options demonstrated satisfactory prosthetic parameters during subsequent follow-ups. However, marginal integrity and discoloration were more prevalent in the onlay group. Periodontal examination revealed that onlays exhibited superior periodontal outcomes compared to crowns, with full crowns showing greater periodontal damage at 1-year and 2-year follow-ups.

Aim: To evaluate and compare the osteogenic effects of LED irradiation at varying distances using MG-63 osteoblast-like cells cultured on titanium discs.

Settings and design: This in vitro experimental study involved human osteosarcoma (MG-63) cells cultured on titanium discs and subjected to LED irradiation at different distances, compared to a non-irradiated control group.

Materials and methods: Forty-two titanium discs were divided into three groups: Control (no irradiation), LED Group 1 (10 mm distance), and LED Group 2 (20 mm distance). All discs were seeded with MG-63 cells and pre-cultured. Experimental groups received a single 2-minute exposure to 660 nm red LED light, while controls received no exposure. Cell viability was measured at 24 and 48 hours using the MTT assay. Cell attachment, growth, and proliferation were assessed at 72, 96, and 120 hours.

Statistical analysis used: Data were analyzed using SPSS v28.0. Two-way ANOVA followed by Tukey's post-hoc test was applied to identify statistically significant differences among groups across time points. A p-value < 0.05 was considered significant.

Results: Both LED-irradiated groups showed significantly enhanced osteogenic activity compared to controls (p < 0.05). Group 1 (10 mm) exhibited the highest cell viability, attachment, and proliferation. Group 2 (20 mm) showed moderate improvement but was inferior to Group 1, indicating distance-dependent effects.

Conclusion: LED therapy enhances osteogenesis on titanium surfaces, with the greatest efficacy observed at a 10 mm irradiation distance. These findings support the use of optimized LED therapy to improve bone healing and implant integration.

Aim: To assess the effectiveness of this Implant T Stabilizing plate in distributing the masticatory stress around the implant placed immediately after maxillary sinus lifting in cases with reduced remaining bone height (3 mm).

Settings and design: In vitro experimental study.

Materials and methods: Two 3D finite element maxillary models with implant placement in 16 region were designed, one without an implant T stabilizing plate and another with an implant T stabilizing plate. Interim removable partial denture with soft liner replacing 16 and 17 was also designed for both models over which the masticatory force of 12 kg was applied. The maximum principal stress generated around the implant and surrounding bone in both models was measured.

Statistical analysis used: Statistical analysis was done by using MedCalc stratistical software - version 23.1.7 in which 'Receiver Operating Characteristic Curve' analysis was performed to check for the sensitivity and specificity of the material used.

Results: The maximum principal stress around the implant and the cortical bone in working model 1 (without the ITS plate) was 5.2972 and 5.2387 mega pascal respectively. The maximum principal stress around the implant and the cortical bone in working model 2 (with ITS plate) was 1.1663 and 4.5568 mega pascal respectively. In the working model 2, the Implant T stabilizing plate absorbs maximum stress of 10.022 mega pascal.

Conclusion: The implant T stabilizing (ITS) plate to the implant placed immediately after maxillary sinus lifting absorbs the maximum stress there by reducing the stress around the implant and surrounding bone even in cases of minimal remaining bone height.

Aim: The aim was to investigate the interaction of the biosynthesized silver nanoparticles (AgNPs) with poly (methyl methacrylate) (PMMA) denture base resin using Fourier transform infrared (FTIR) spectroscopy.

Settings and design: This was a comparative in vitro study.

Materials and methods: In the present study, AgNPs were biosynthesized using Trigonella foenum-graecum leaf extract. The biosynthesized AgNPs at concentrations 32 and 64 μg/ml were incorporated into PMMA, and characterization was carried out using FTIR spectroscopy.

Statistical analysis used: None, as only one sample from each group was subjected for FTIR spectroscopy.

Results: The biosynthesis of AgNPs was confirmed by a color change from green to brown. When compared to the control group, the test group showed no changes in the band locations for C = C and C = O. Importantly, the infrared spectra of all specimens with AgNP additives exhibited the distinctive peaks associated with PMMA.

Conclusion: Based on the study's limitations, it was determined that AgNPs had physically interacted with the PMMA matrix.

Conventional alveolar ridge splitting (ARS) technique involves a significant risk which may prove problematic. This case report presents the first documented application of dynamic navigation system (DNS)-guided ARS, demonstrating a precise approach to implant placement in a challenging anatomical scenario. A 37-year-old partially edentulous patient presented with missing mandibular posterior teeth. Clinical examination revealed a deficient alveolar ridge. Cone-beam computed tomography evaluation showed a Siebert's Class I resorbed ridge with 2.5 mm width and bone density ranging from 870 to 1040 Hounsfield Units in the #46 and #47 regions. Creating and designing three-dimensional virtual guide slits and implant planning using DNS were done in patient with insufficient bone width in the mandibular molar region. Piezoelectric ARS, osteotomy preparation with implant placement was done. 0.70 and 0.26 mm deviations at #46 and 0.50 and 0.01 mm deviations at #47 were observed at implant entry and implant apex, respectively. The angular deviations were optimal. ARS using real-time navigation appears to be an efficient and promising technique.