Background: Intraoral scanner (IOS) is a medical device used for capturing direct optical impressions and composed of a handheld camera (hardware), a computer and software. Digital impressions by intraoral scanning have become an increasingly popular alternative to conventional impressions. The aim of this systematic review is to assess the studies regarding the various available technologies for IOS and evaluate the most accurate IOS system for cases with multiple implants and identify the factors that can influence its accuracy. Materials and Methods: A comprehensive electronic search was done in online databases, 'Pubmed', 'Google Scholar' and 'Cochrane' based on pre-determined eligibility criteria. In-vitro studies, In-vivo studies and Randomized controlled trials assessing the accuracy of intra-oral scanner technology were selected after thorough screening. The search strategy covered all studies published until February 2019 and yielded a total of 11 articles out of which 8 studies were determined to fulfil the inclusion criteria and were selected for this review. Data extraction from the included studies was conducted by the primary author and reviewed by the second author. Results: The information collected included sample size and population, study design, intervention, scanning methods, comparisons and outcome measures. 5 out of 8 included studies compared the distance deviation of the acquired scans from the true values while the remaining 3 studies gave trueness and precision values as the outcome variables. A forest plot on scanner precision displayed slightly higher precision levels in the TRIOS scanner compared to the other intraoral scanners. Conclusion: Despite the limitations this study, it can be concluded that active wavefront sampling is more accurate than the other intraoral scanning technology employed by commercial scanners.

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Aim: The aim of this systematic review is to analyze the existing evidence on the quality of life of patients completely edentulous in the mandible. Materials and Methods: A search questionnaire was formulated using population intervention comparison outcome (PICO) analysis, and a comprehensive search was initiated in PubMed Central, Medline, Cochrane, and Google Scholar databases for the related topics. Manuscripts published till December 2019 were included in this review. Out of the 63 articles obtained from searching all databases, 27 studies were excluded based on the title and abstract. Out of the remaining 36 studies, 12 were excluded based on the inclusion and exclusion criteria of our interest and 24 were included on the basis of core data. Results: One review author identified randomized trials meeting inclusion criteria for this review. Two review authors extracted data and assessed study quality. The oral health-related quality of life in completely edentulous mandibular patients wearing implant-supported overdentures was better when compared to conventional tissue-supported complete denture, and a minimum two implant-supported mandibular complete denture has sufficient improvement in oral health-related quality of life. Conclusion: There are about more than 170 reviews and clinical trials that have been published in support of the same for the past two decades. Thus, the clinicians may not be tempted in placing additional implants in well-formed mandibular edentulous ridges. To enhance the understanding of mandibular implant overdenture treatment, clinicians must scrutinize the existing evidence and formulate a protocol by striking a balance between efficient and evidence based treatment.

The behaviour of hafnium as surface coating in biological environments has not been studied. Little is known about osseointegration of hafnium-coated titanium implants. Thus, further studies of hafnium coating under biological conditions are required in order to determine the suitability of this material, as a surface coating for biomedical application. The aim of the study is to analyse the difference between hafnium-coated titanium and uncoated titanium by evaluating the osseointegration ability of hafnium metal and mechanism of which promotes better bone integration. The study was conducted with a split mouth design on 16 Wistar Albino rats of both sexes, at the age of 6-7 months, weighing 2526.5 ± 74.4   g . Self-tapping titanium osteosynthesis screws ( 4   mm × 2   mm ) (LeForte System Bone Screw®) were implanted in the mandible of rats: Group A (pure titanium screws, n = 12 ) and Group B (hafnium-coated screws, n = 12 ). The implanted screws’ stability was checked and noted with a specially customised torque apparatus during insertion and removal of implant. The tissue sections were then processed for hematoxylin and eosin and Masson’s trichrome for bone and connective tissue examination, after 4 and 8 weeks of placement. Hafnium coating appears to have offered similar biocompatibility (aspartate transaminase (AST), alanine aminotransferase (ALT), and creatine kinase (CK) enzyme assay), statistically significant improvement (independent Student’s t -test, p < 0.05 ) in insertion torque ( 25.42 ± 3.965 ) and removal torque ( 29.17 ± 2.887 ) than commercially pure titanium with insertion torque ( 22.08 ± .575 ) and removal torque ( 25.42 ± 2.575 ). Hafnium coating in the rat mandible showed promising osseointegration with good tissue biocompatibility. Further human trials of hafnium-coated implants are needed to understand the biological behaviour better to enhance clinical performance.