Biomechanical behavior of all-ceramic endocrowns fabricated using CAD/CAM: A systematic review

PURPOSE

This study performed a systematic review to assess the biomechanical behavior of all-ceramic endowcrowns fabricated using computer-aided design and computer-aided manufacturing (CAD/CAM) for the restoration of endodontically treated teeth.

STUDY SELECTION

Three electronic databases (PubMed, Web of Science, and Scopus) were searched by operators specializing in health sciences databases searches to answer the following focused question based on the Population, Intervention, Comparison, Outcome (PICO) format: "Whether all-ceramic CAD/CAM endocrowns (Intervention) used to restore human endodontically treated teeth (Population) exhibit superior fracture resistance (Outcome) compared to non-CAD/CAM all-ceramic or non-ceramic endocrowns (Comparison)." The methodological quality assessment was performed using previously conducted systematic reviews of in vitro studies. The outcomes were expressed as the mean ± the standard deviation (SD).

RESULTS

Seventeen in vitro studies were included. The materials used in these studies were lithium disilicate glass-ceramic, polymer-infiltrated ceramic, zirconia-reinforced lithium silicate glass-ceramic, resin/hybrid nanoceramics, zirconia-reinforced lithium silicate ceramics, and feldspathic ceramic. The fracture resistance of endocrowns using different ceramics varied as follows: (i) IPS e.max CAD (2863.62 ± 51.47 N), (ii) Vita Enamic (1952 ± 378 N), (iii) Vita Suprinity (1859 ± 588 N), (iv) Cerasmart (1981 ± 169.5 N), (v) LAVA Ultimate (2484 ± 464 N), (vi) Celtra Duo (1618.30 ± 585.00 N), and (vii) Cerec Blocs (236.29 ± 32.12 N).

CONCLUSIONS

CAD/CAM all-ceramic endocrowns can withstand occlusal forces in the posterior region. All-ceramic endocrowns improve the fracture strength of endodontically treated teeth. Lithium disilicate crowns were commonly and successfully used in the included studies. More in vitro investigations that implement uniformity in material and measurement approaches are required to strengthen the evidence currently available in the literature regarding the durability of all-ceramic endocrowns.

Efficacy, safety, and potential industry bias in using deoxycholic acid for submental fat reduction ‒ A systematic review and meta-analysis of randomized clinical trials

Lipolytic substance injections to reduce localized fat have been extensively used because it is a low-invasive method. This review aimed to evaluate the efficacy and safety of deoxycholic acid in submental fat reduction compared to a placebo and investigate the potential industry sponsorship bias in the results of randomized clinical trials on this topic. Ten electronic databases were extensively searched for randomized clinical trials without restriction on language and year of publication. Two reviewers extracted the data and assessed the individual risk of bias in the studies with the RoB 2.0 tool. The industry sponsorship bias was evaluated according to citations in the articles regarding industry funding/sponsorship throughout the texts. Fixed and random effects meta-analyses were performed, and the results were reported in Risk Ratio (RR) at a 95% Confidence Interval (95% CI). The initial search provided 5756 results, of which only five were included. Only two studies had a low risk of bias. All studies showed a potential industry bias. The meta-analysis showed that patients treated with deoxycholic acid had significant positive results for all efficacy outcomes and a higher risk of fibrosis, pain, erythema, numbness, swelling, edema, pruritus, nodules, headache, and paresthesia. The low to moderate certainty of evidence found allows concluding that deoxycholic acid is effective in submental fat reduction, causing well-tolerated adverse effects. However, all eligible studies showed a potential industry bias.

Sponsorship Bias in Clinical Trials in the Dental Application of Probiotics: A Meta-Epidemiological Study

Many experimental and clinical trials have investigated the dental application of probiotics, although the evidence concerning the effects of probiotic supplements is conflicting. We aimed to examine whether sponsorship in trials about dental applications of probiotics is associated with biased estimates of treatment effects. Overall, 13 meta-analyses involving 48 randomized controlled trials (23 with high risk of sponsorship bias, 25 with low risk) with continuous outcomes were included. Effect sizes were calculated from differences in means of first reported continuous outcomes, divided by the pooled standard deviation. For each meta-analysis, the difference in standardized mean differences between high-risk and low-risk trials was estimated by random effects meta-regression. Differences in standardized mean differences (DSMDs) were then calculated via meta-analyses in a random effects meta-analysis model. A combined DSMD of greater than zero indicated that high-risk trials showed more significant treatment effects than low-risk trials. The results show that trials with a high risk of sponsorship bias showed more significant intervention effects than did low-risk trials (combined DSMD, 0.06; 95% confidence interval, 0.3 to 0.9; p < 0.001), with low heterogeneity among meta-analyses (I2 = 0%; between-meta-analyses variance τ2 = 0.00). Based on our study, high-risk clinical trials with continuous outcomes reported more favorable intervention effects than did low-risk trials in general.

Influence of Sponsorship Bias on Treatment Effect Size Estimates in Randomized Trials of Oral Health Interventions: A Meta-epidemiological Study

BACKGROUND

In this meta-epidemiological study, we aimed to examine associations between treatment effect size estimates and sponsorship bias in oral health randomized clinical trials.

METHODS

We selected oral health related meta-analyses that included a minimum of five randomized controlled trials. We extracted data, in duplicate, related to influence of sponsorship bias. We quantified the extent of bias associated with influence of sponsorship on the magnitude of effect size estimates of continuous variables using a two-level meta-meta-analytic approach with random-effects models to allow for intra- and inter-meta-analysis heterogeneity.

RESULTS

We initially identified 540 randomized trials included in 64 meta-analyses. Risk of sponsorship bias was judged as being "unclear" in 72.8% (n = 393) of the trials, while it was assessed as "low" in 16.7% (n = 90) and as "high" in 10.6% (n = 57) of the trials. Using a meta-epidemiological analysis (37 meta-analyses, including 328 trials that analyzed 85,934 patients), we identified statistically significant larger treatment effect size estimates in trials that had "high or unclear" risk of sponsorship bias (difference in treatment effect size estimates=0.10; 95% confidence intervals: 0.02 to 0.19) than in trials that had "low" risk of sponsorship bias.

CONCLUSIONS

We identified significant differences in treatment effect size estimates between dental trials based on sponsorship bias. Treatment effect size estimates were 0.10 larger in trials with "high or unclear" risk of sponsorship bias.

PRACTICAL IMPLICATIONS

Clinicians should have an adequate knowledge of sponsorship bias in a clinical trial and be able to estimate the degree to which the conclusions of a systematic review are synthesized and interpreted, based on trials with low risk of sponsorship bias.

Does Type of Sponsorship of Randomized Controlled Trials Influence Treatment Effect Size Estimates in Rehabilitation: A Meta-Epidemiological Study

BACKGROUND

Sponsorship bias could affect research results to inform decision makers when using the results of these trials. The extent to which sponsorship bias affect results in the field of physical therapy has been unexplored in the literature. Therefore, the main aim of this study was to evaluate the influence of sponsorship bias on the treatment effects of randomized controlled trials in physical therapy area.

METHODS

This was a meta-epidemiological study. A random sample of randomized controlled trials included in meta-analyses of physical therapy area were identified. Data extraction including assessments of appropriate influence of funders was conducted independently by two reviewers. To determine the association between biases related to sponsorship biases and effect sizes, a two-level analysis was conducted using a meta-meta-analytic approach.

RESULTS

We analyzed 393 trials included in 43 meta-analyses. The most common sources of sponsorship for this sample of physical therapy trials were government (n = 205, 52%), followed by academic (n = 44, 11%) and industry (n = 39, 10%). The funding was not declared in a high percentage of the trials (n = 85, 22%). The influence of the trial sponsor was assessed as being appropriate in 246 trials (63%) and considered inappropriate/unclear in 147 (37%) of them. We have moderate evidence to say that trials with inappropriate/unclear influence of funders tended to have on average a larger effect size than those with appropriate influence of funding (effect size = 0.15; 95% confidence interval = -0.03 to 0.33).

CONCLUSIONS

Based on our sample of physical therapy trials, it seems that most of the trials are funded by either government and academia and a small percentage are funded by the industry. Treatment effect size estimates were on average 0.15 larger in trials with lack of appropriate influence of funders as compared with trials with appropriate influence of funding. Contrarily to other fields, industry funding was relatively small and their influence perhaps less marked. All these results could be explained by the relative youth of the field and/or the absence of clear industry interests. In front of the call for action by the World Health Organization to strengthen rehabilitation in health systems, these results raise the issue of the need of public funding in the field.

Reporting of conflict of interest and sponsorship in dental journals

OBJECTIVE

Detailed information on potential conflict of interest (COI) and sponsorship is pivotal for the adequate understanding and appropriate interpretation of the reported study results. The reporting of COI and sponsorship and any potential associations with study characteristics in publications of all dental journals with impact factor was examined.

METHODS

The Web of Science database was searched, in March 2019, for articles published from February 28, 2018 to March 1, 2019. A random a sample of 1000 articles in English was selected. Two independent authors extracted the following article characteristics: type of article, dental field, number of authors, country/continent affiliation of the first author, dental journal, journal impact factor, number of citations, Altmetric score, type of COI and sponsorship. Disagreements during data extraction were resolved by discussion and consensus. Descriptive statistics were calculated for the selected variables and multinomial logistic regression was implemented to assess the association between COI, sponsorship, and the other variables.

RESULTS

3% of dental publications declared a COI, whereas in 32.5% of publications the presence of COI was unclear. The most prevalent type of COI was financial (n = 26). Non-profit organizations funded 37.2% of the articles, while the sponsorship for 40.4% articles was unclear. Regression analysis showed that publications reporting COI had greater odds of receiving sponsorship from for-profit sources.

CONCLUSIONS

Sponsorship and COI information seem to be underreported in dental journals. Efforts should be made by authors, journals, and publishers to provide more comprehensive information to allow the reader to understand the potential impact of sponsorship and COI on study results.

CLINICAL SIGNIFICANCE

The underreporting of COI and sponsorship in dental articles hinders the interpretation of findings by readers. The results of the present study bring attention to this important topic as well as guide further improvements on the reporting of COI and sponsorship in dental articles.

Clinical trials sponsored by industry and other private organizations

The present manuscript discussed some relevant aspects related to private sponsored clinical trials in dentistry. For decades, the academy has been the major responsible for research in Brazil. Distant from the trade sector, academic research has not always provided clear benefits to society. A key aspect of making benefits clearer is the process of scientific knowledge transference to decision-makers, which is, in fact, the ground of evidence-based dentistry. Although private sponsoring of clinical research seems to be part of the research progress of the business rates, investment in Brazil is lower than those observed in other countries. It is particularly important to understand that instead of creating its own rules, dentistry imported the high-quality standards originally designed for pharmaceutical studies. Therefore, it is critical to understand the original rules and how dental items are classified by regulatory agencies. In fact, knowledge about international and local regulation is a basic assumption in industry-sponsored research. Despite globalization, the identification of industry-sponsored studies through open access databases is still very hard and time-demanding. A common concern when conducting industry-sponsored trials is study biases. Fortunately, many relevant organizations, academic and industry groups, have been working seriously against that. Finally, for less experienced researchers, many aspects related to industry-sponsored studies - such as confidentiality, authorship, budget - are deeply discussed until a final version of the trial agreement can be written and signed, protecting all sides. In short, the scenario should be improved, but it already represents a nice opportunity for dental research.

Clinical evaluation of marketed orthodontic products: are researchers behind the times? A meta-epidemiological study

BACKGROUND

The role of marketing and industry in the treatment decisions of orthodontists has received increasing attention in recent years with clinical research typically undertaken subsequent to established use of these devices and often failing to confirm the promise of manufacturers' claims. This meta-epidemiological study was undertaken to assess the proportion of clinical trials in orthodontics evaluating commercially marketed products and to evaluate the direction of the results of these studies.

METHODS

Electronic searching was undertaken to identify randomized controlled trials (RCTs) published over a 5-year period (1 January 2012 to 31 December 2016). Data obtained included the type of marketed intervention, direction of effect and declaration of both industry sponsorship and conflict of interest.

RESULTS

Eighty-four RCTs published in 23 scientific journals were included with the highest percentage in the American Journal of Dentofacial Orthopedics (AJO-DO) (23.8%), followed by the European Journal of Orthodontics (EJO) (14.3%), Journal of Orthodontics (JO) (10.7%) and Angle Orthodontist (AO) (10.7%). Overall, 45% (38/84) of clinical trials assessed involved analysis of marketed products after their introduction. Interventions to improve oral health or circumvent the risk of iatrogenic damage, such as white spot lesions, were most commonly assessed (15.8%), with the relative merits of non-surgical adjuncts (14.1%) and other orthodontic auxiliaries (13.1%) also frequently evaluated. In 44% of RCTs, a positive effect of the marketed intervention was not reported. Industry sponsorship of the research was declared in 9.5% RCTs. No significant associations between the direction of the effect and both declaration of industry sponsorship (p = 0.56) and conflict of interest (p = 0.96) were detected. Moreover, for marketed and non-marketed products, no significant associations for both declaration of industry sponsorship (p = 0.44) and conflict of interest (p = 0.28) were found.

CONCLUSIONS

Almost half of orthodontic clinical trials over the past 5 years involve analysis of marketed products after their introduction. The results highlight a potential source of waste in orthodontic research emanating from existing approaches to licensing and marketing of orthodontic products.