Protocol registration improves reporting quality of systematic reviews in dentistry.

BACKGROUND: The aims of this study were to assess whether the previous registration of a systematic review (SR) is associated with the improvement of the quality of the report of SRs and whether SR registration reduced outcome reporting bias. METHODS: We performed a search in PubMed for SRs in dentistry indexed in 2017. Data related to SR registration and reporting characteristics were extracted. We analyzed if the reporting of 21 characteristics of included SRs was associated with the prospective registration of protocols or reporting of a previously established protocol. The association between prospective registering of protocols, reporting of funding and number of included studies versus outcome reporting bias was tested via multivariable logistic regression. RESULTS: We included 495 SRs. One hundred and 62 (32.7%) SRs reported registering the SR protocol or working from a previously established protocol. Thirteen reporting characteristics were described statistically significant in SRs registered versus SRs that were not. Publication bias assessment and Report the number of participants showed the highest effects favoring the register (RR 1.59, CI 95% 1.19-2.12; RR 1.58, CI 95% 1.31-1.92 respectively). Moreover, Registration was not significantly linked with the articles' reporting statistical significance (OR 0.96, CI 95% 0.49-1.90). CONCLUSION: There is a positive influence of previously registering a protocol in the final report quality of SRs in dentistry. However, we did not observe an association between protocol registration and reduction in outcome reporting bias.

Restorative Possibilities Using Zirconia Ceramics for Single Crowns.

Two clinical cases are presented to explore technical differences and discusses the advantages and disadvantages of using veneered or monolithic zirconia to manufacture posterior single crowns. The first case describes the clinical steps in manufacturing a monolithic crown on a mandibular left second premolar using high translucency zirconia. It shows the use of a conservative tooth preparation based on the superior mechanical properties that this material presents as well as the final optical characteristics achieved by shading and staining. In the second case, a conventional bilayer restorative treatment was made using zirconia framework followed by veneering with feldspar ceramic on a mandibular left first molar. Recent literature indicates that each of these restorative alternatives presents specific advantages and disadvantages. Factors such as mechanical performance, fracture, esthetic characteristics, clinical success, complication rates, adhesion and antagonist wear performance are discussed comparing the two restorative assemblies. The data highlight that monolithic crowns prevent a major problem reported on bilayer restorations: the chipping of veneering ceramic. Monolithic crowns also allow minimally invasive tooth preparations, thus increasing tooth remnant preservation. However, data that support esthetic performance similarity between monolithic and bilayer assemblies are lacking, thus the predictability of use is restricted for the posterior region, as cases demanding high esthetic appeal continue to fundamentally use bilayer restorations. Failures were not found, and patient satisfaction was reported in both techniques after the 12-month follow up.

Systematic reviews in dentistry: Current status, epidemiological and reporting characteristics.

OBJECTIVE: This study aimed to evaluate the epidemiological and reporting characteristics of systematic reviews (SRs) in dentistry indexed within PubMed during the year 2017. METHODS: We searched for SRs in dentistry indexed within PubMed in 2017. Study selection was undertaken by two reviewers independently. Data related to epidemiological and reporting characteristics were extracted by one of three reviewers. A descriptive analysis of the data was performed. Characteristics of SRs were analyzed considering all SRs included and subgrouped by dental specialties. In addition, we explored if the reporting of 24 characteristics of treatment/therapeutic SRs was associated with the self-reported use of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Statement calculating the risk ratio (RR) with a 95% confidence interval for each characteristic. RESULTS: 495 articles fulfilled the eligibility criteria. The main specialty considered was Oral Surgery numbering 75 articles. Brazil presented the highest contribution with 117 SRs (23.6%). The reporting quality was variable. Items such as, use of the term "systematic review", or "meta-analysis" in the title or abstract was well reported. In contrast, the study risk of bias/quality assessment method was not reported in 40.5% of SRs. In addition, only four reporting characteristics were described more often in those SR that reported using the PRISMA Statement. CONCLUSION: A large number of SRs were published in dentistry in 2017 and the reporting and epidemiological characteristics varied among dental specialties. There is a mandatory need to improve the quality of reporting and conduct of SRs in dentistry. CLINICAL SIGNIFICANCE: Poor reporting and conduction of SRs could generate SRs with imprecise and biased results.

Influence of Different Implant Geometry in Clinical Longevity and Maintenance of Marginal Bone: A Systematic Review.

PURPOSE: To assess, through a systematic review, the influence of different implant geometries on clinical longevity and maintenance of marginal bone tissue. METHODS: An electronic search was conducted in MEDLINE, Scopus, and Web of Science databases, limited to studies written in English from 1996 to 2017 using specific search strategies. Only randomized controlled trials (RCTs) that compared dental implants and their geometries were included. Two reviewers independently selected studies, extracted data, and assessed the risk of bias of included studies. RESULTS: From the 4006 references identified by the search, 24 were considered eligible for full-text analysis, after which 10 studies were included in this review. A similar behavior of marginal bone loss between tapered and cylindrical geometries was observed; however, implants that had micro-threads in the neck presented a slight decrease of marginal bone loss compared to implants with straight or smooth neck. Success and survival rates were high, with cylindrical implants presenting higher success and survival rates than tapered ones. CONCLUSIONS: Implant geometry seems to have little influence on marginal bone loss (MBL) and survival and success rates after 1 year of implant placement; however, the evidence in this systematic review was classified as very low due to limitations such as study design, sample size, and publication bias. Thus, more well-designed RCTs should be conducted to provide evidence regarding the influence of implant geometry on MBL and survival and success rates after 1 year of implant placement.