Development and validation of a risk-of-bias tool for assessing in vitro studies conducted in dentistry: The QUIN.

STATEMENT OF PROBLEM: Systematic reviews and meta-analyses have emerged as forerunners of evidence-based dentistry, but assessing the quality of the available research is essential so that it can be applied to clinical practice. While a wide variety of risk-of-bias tools are available, each specifically developed for different study designs, a comprehensive tool exclusively framed to assess the quality of in vitro dental studies is lacking. PURPOSE: The purpose of this study was to develop and validate a tool to evaluate the quality and risk of bias of in vitro dental studies. MATERIAL AND METHODS: A Delphi panel was established to conceptualize and develop the Quality Assessment Tool For In Vitro Studies (QUIN Tool). The tool was evaluated by using content validity and reliability testing methods. RESULTS: The QUIN Tool includes 12 points along with scoring and grading options to allow clinicians to evaluate the quality of in vitro studies. This tool shows good content validity and reliability. CONCLUSIONS: The QUIN Tool is user-friendly, efficient, and effective for evaluating the risk of bias of in vitro studies.

Effect of different finish line preparations on the marginal and internal adaptation of cobalt-chromium metal alloy copings fabricated by using CAD-CAM technology: A systematic review and meta-analysis.

STATEMENT OF PROBLEM: The marginal and internal adaptation of a fixed dental prosthesis depends on a variety of factors, finish line designs being one of them. A clear consensus as to which finish line design can provide a better marginal and internal adaptation with respect to cobalt-chromium metal alloy copings fabricated by using computer-aided design and computer-aided manufacturing (CAD-CAM) technology is lacking. PURPOSE: The purpose of this systematic review and meta-analysis was to evaluate the effect of different finish line preparations on the marginal and internal adaptation of cobalt-chromium metal alloy copings fabricated by using CAD-CAM technology. MATERIAL AND METHODS: Electronic (PubMed, Cochrane, EBSCOhost, and Google Scholar) and manual searches were conducted for articles published from January 2010 to December 2020 to identify relevant studies evaluating the effect of different finish line preparations (chamfer, deep chamfer, shoulder, rounded shoulder) on the marginal and internal adaptation of cobalt-chromium metal alloy copings fabricated by using CAD-CAM technology. RESULTS: A total of 573 articles were obtained via electronic search, and 10 articles were obtained through manual search, of which 24 in vitro studies were selected after title, abstract, and full-text screening and were included for both qualitative and quantitative analyses. The marginal adaptation was evaluated under the parameters of marginal gap, absolute marginal discrepancy, and vertical marginal discrepancy, whereas internal adaptation was evaluated under the parameters of internal gap, cervical discrepancy, axial discrepancy, and occlusal discrepancy. The methods of CAD-CAM fabrication (direct metal laser sintering, hard milling, and soft milling) were considered under the subgroup analysis. CONCLUSIONS: An overall better marginal and internal adaptation was observed with shoulder and rounded shoulder finish line designs when CAD-CAM methods were used for coping fabrication. Marginal and internal adaptation in chamfer and deep chamfer finish line designs showed better results with soft milling and direct metal laser sintering methods, whereas shoulder finish line showed better results with hard milling.

An evaluation of virtually planned and 3D-printed stereolithographic surgical guides from CBCT and digital scans: An in vitro study.

STATEMENT OF PROBLEM: The process of manufacturing stereolithographic surgical guides for static computer-guided implant placement involves a series of steps. Errors can be incorporated in various forms and at various stages of manufacturing these guides. Errors introduced during this process have not been fully investigated. PURPOSE: The purpose of this in vitro study was to assess the errors introduced during the manufacture of stereolithographic surgical guides generated from cone beam computed tomography (CBCT) and digital scans by using a virtual implant planning software. MATERIAL AND METHODS: Ten stereolithographic surgical guides with the associated standard tessellation language (STL) files of their virtual design were used in this study. The STL files of the virtual design and the scans of the stereolithographic surgical guides were superimposed. Linear deviation at the center of the sleeve top and sleeve base and the angular deviation at the center of the sleeve were measured. RESULTS: The minimum and maximum linear deviation at the center of the sleeve top and the sleeve base was found to be 0 and 40 µm, with less linear deviation observed at the center of the sleeve top (mean ±standard deviation 18 ±7 µm) than at the center of the sleeve base (20 ±7 µm). The minimum and maximum angular deviation at the center of the sleeve was found to be 0 degrees and 5.9 degrees respectively, with a mean ± standard deviation of 1.36 ±0.74 degrees. CONCLUSIONS: Errors were found in the sleeve position between the virtual design and the stereolithographically manufactured surgical guide. This error may introduce errors in the final implant position.

Comparative evaluation of the shear bond strength of adhesive and self-adhesive resin luting agents to three commercially available composite core build-up materials: An in vitro study.

AIM: The aim of the study was to evaluate the shear bond strength of adhesive and self-adhesive resin luting agents (RLAs) to three commercially available composite core build-up materials (CBMs). SETTINGS AND DESIGN: Comparative -invitro study. MATERIALS AND METHODS: Sixty samples, 20 each of self-cure (Incore, Medicept: Group I), light cure (Light-Core, Bisco: Group II), and dual cure (LuxaCore Z-Dual, DMG America: Group III) composite CBMs were made in the lower mold space of a customized stainless steel jig. They were further subdivided into subgroups A and B for bonding with the adhesive (RelyX Ultimate, 3M ESPE) and self-adhesive (RelyX Unicem, 3M ESPE) RLAs respectively. For specimens in subgroup A, the bonding agent (Scotchbond Universal Adhesive, 3M ESPE) was rubbed onto the surface for 20 s prior to bonding with the adhesive RLA. For specimens in subgroup B, no pretreatment of the surface was carried out. The CBM-luting agent sample was tested for the shear bond strength in a universal testing machine. STATISTICAL ANALYSIS USED: ANOVA, Tukey's multiple comparison, and independent t-test. RESULTS: Adhesive RLA showed the highest shear bond strength to light cured composite CBM. Self-adhesive RLA showed the highest shear bond strength to dual-cured composite CBM. Adhesive RLA showed higher shear bond strength to all three composite CBMs as compared to the self-adhesive luting agent. This difference was statistically significant for the self-cure and light cure composite CBMs. CONCLUSION: Adhesive RLA showed greater shear bond strengths to all the three groups of composite CBMs as compared to self-adhesive RLA.

An evaluation of antagonist enamel wear opposing full-coverage zirconia crowns versus other ceramics full-coverage crowns and natural enamel - An umbrella review.

AIM: The aim of this umbrella review was to systematically review the systematic reviews on antagonist enamel wear opposing zirconia crowns compared to other ceramics and natural enamel. SETTINGS AND DESIGN: This was an umbrella review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. MATERIALS AND METHODS: An electronic search of PubMed, Cochrane Central, EBSCOhost, and Google Scholar search engines for articles published from January 1, 2013, to January 1, 2023, was conducted using keywords "enamel wear," "zirconia," "feldspathic," "dental ceramics," and "Y-TZP" to identify systematic reviews on antagonist enamel wear opposing zirconia crowns compared to other ceramics and natural enamel. STATISTICAL ANALYSIS USED: Qualitative analysis. RESULTS: A total of 86 articles were obtained through electronic search, of which four articles were selected after abstract screening that met the inclusion criteria for evaluating antagonist enamel wear. As compared to feldspathic groups, zirconia had substantially less antagonist wear, while surface polishing exhibited less enamel wear than glazing. Because of the heterogeneity in study design, measurement methods, and outcome variables, a meta-analysis was not possible. CONCLUSIONS: Over time, the opposing enamel wear caused by polished monolithic zirconia will be either equal to or less than that of natural enamel wear. Polished monolithic zirconia also maintains lower values of enamel wear compared to metal ceramics, feldspathic porcelains, and lithium disilicate.

A comparative evaluation of internal and marginal fits of custom post and core fabricated using conventional and two digital techniques: An in vitro study.

AIM: The purpose of this in vitro study was to comparatively evaluate the marginal and internal fits of cobalt-chromium metal custom post and core fabricated using a conventional technique with two digital techniques. SETTINGS AND DESIGN: The study was designed in an in-vitro study setting. MATERIALS AND METHODS: Five sets of custom post and core restorations were fabricated using the conventional (Group 1) and two semi digital methods (digital scanning of the resin pattern and computer aided additive manufacturing, and digital scanning of the silicone impression and subsequent computer aided designing [CAD] computer aided manufacturing fabrication) (Group 2 and 3). Marginal and internal fits of the posts were evaluated using a micro computed tomography scan at various points. STATISTICAL ANALYSIS USED: A one way ANOVA test of the scores was made to evaluate the effect of different methods of custom post and core fabrication on marginal and internal fits. Bonferroni adjusted post hoc tests were conducted for intergroup comparison. RESULTS: Least marginal gap was reported in Group 3 (82.5 ± 14.36 µm) followed by Group 1 (110 ± 25.19 µm) and Group 2 (112.5 ± 26.75 µm). Least internal gap at cervical, middle and apical as well as overall values were observed in Group 3 (78 ± 9.25 µm, 72 ± 7.79 µm, 160 ± 15.81 µm, 103.3 ± 4.43 µm) followed by Group 1 (113.5 ± 25.35 µm, 132.5 ± 19.92 µm, 502 ± 74.63 µm, 249.3 ± 25.44 µm) and Group 2 (114.5 ± 21.68 µm, 133.5 ± 19.57 µm, 598 ± 87.86 µm, 282 ± 28.91 µm) respectively. The results of one-way ANOVA and Bonferroni adjusted post hoc tests for marginal gap did not show any statistically significant difference between the three groups (P > 0.05) but revealed statistically significant difference (P = 0.02) in internal gap values at the cervical, middle, and apical regions as well as overall internal gap region between the three groups. CONCLUSIONS: Better marginal and internal fits were observed in custom post and core fabricated by digital scanning of the silicone impression and subsequent CAD as compared to those fabricated by the other two groups.

Validation of Digital Impressions' Accuracy Obtained Using Intraoral and Extraoral Scanners: A Systematic Review.

BACKGROUND: At present, the evidence regarding digital impressions' accuracy recorded by using digital scanners is lacking. This systematic review aimed to evaluate whether the type of scanning (intraoral/extraoral) affects the Accuracy of Digital Impressions. METHOD: Two independent reviewers performed a systematic search in the database both electronically and manually (PubMed, Ebsco HOST, the Cochrane Library, and Google Scholar) for articles published from 1 January 2010 to 1 December 2022. This study was registered with the International Prospective Register of Systematic Reviews (PROSPERO CRD42020188765) and followed the PRISMA statement. The question in focus was as follows: Does the type of scanning (intraoral or extraoral) affect the accuracy of digital impression? RESULTS: A total of 449 papers were obtained by searching electronically and manually. In total, 15 complete-text papers qualified for assessment based on eligibility criteria. After reading the full-text articles, five studies were excluded. Ten studies were selected for the qualitative analysis. The qualitative data reported that the accuracy of both types of scanners (intraoral and extraoral) lies within the range of clinical acceptability. Nevertheless, the intraoral scanners seem to be more accurate when compared to the extraoral scanners for a partial arch situation. CONCLUSIONS: Scanning type affects the accuracy of the digital impression. Various factors influence the scanning ability. Intraoral scanners seem to be more accurate compared to extraoral scanners for a partial arch situation. More studies comparing the accuracy of the intraoral scanner and extraoral scanner for a complete arch scan and in an in vivo study setting are needed.

Recreating first digit with silicone prosthesis.

The hand is an integral part of our body. Any deviation in hand anatomy not only affects the day-to-day function but it even results in unesthetic appearance. Rehabilitation of these deformities is done either by microsurgery or with the help of silicone prosthesis. Nonsurgical treatment was carried out, where rehabilitation of the first digit was done with customized silicone prosthesis. Replacement of these deformities with silicone prosthesis is usually done by prosthetist. However, we being an oral and maxillofacial prosthodontist, replacement of these missing complete or partial fingers, thumb, ear, and nose is also done by prosthodontist. Rehabilitation of these deformities with silicone prosthesis can offer psychological, functional, and esthetic advantages. Recent advances in materials and skill of an individual made it possible to fabricate esthetically pleasing prosthesis. Mini implants are widely used for retaining silicone prosthesis; however, they are expensive and need surgical intervention. Vacuum-retained silicone-retained silicone prosthesis is a good and minimal invasive option for these patients. This clinical report describes a straightforward technique for fabricating silicone thumb prosthesis for a patient with amputated thumb.