Methodological assessment of systematic reviews of in-vitro dental studies

The confidence in the results of physiotherapy systematic reviews in the musculoskeletal field is not increasing over time: a meta-epidemiological study using AMSTAR 2 tool

OBJECTIVES

To assess the confidence in the results of systematic reviews on the effectiveness of physiotherapy for musculoskeletal conditions in the past 10 years and to analyze trends and factors associated.

METHODS

This is a metaepidemiological study on systematic reviews (SRs) with meta-analysis of randomized controlled trials (RCTs). MEDLINE, Cochrane Database of Systematic Reviews, CINAHL, and PEDro were searched for SRs of RCT on physiotherapy interventions for musculoskeletal disorders from December 2012 to December 2022. Two researchers independently screened the records based on the inclusion criteria; a random sample of 100 studies was selected, and each journal, author, and study variable was extracted. The methodological quality of SRs was independently assessed with the AMSTAR 2 tool. Any disagreement was solved by consensus.

RESULTS

The confidence in SRs results was critically low in 90% of the studies, and it did not increase over time. Cochrane reviews are predominantly represented in the higher AMSTAR 2 confidence levels, with a statistically significant difference compared to non-Cochrane reviews. The last author's H-index is the only predictor of higher confidence among the variables analyzed (OR 1.04; 95% CI: 1.01, 1.06).

CONCLUSION

The confidence in SRs results is unacceptably low. Given the relevance of musculoskeletal disorders and the impact of evidence synthesis on the clinical decision-making process, there is an urgent need to improve the quality of secondary research by adopting more rigorous methods.

Citric Acid Conditioning as an Alternative to EDTA for Growth Factors Release and Stem Cell Response in Regenerative Endodontics: A Systematic Review of In Vitro Studies

INTRODUCTION

Citric acid (CA) conditioning may be a promising alternative to ethylenediaminetetraacetic acid (EDTA) in regenerative endodontic procedures, as reported to improve growth factors' release from dentin. This review systematically investigated the effect of CA conditioning on the growth factors release from dentin and cell behavior compared to EDTA conditioning.

METHODS

Searches were conducted (PubMed/MEDLINE, Scopus, Web of Science, Embase, SciELO, Cochrane Library, and grey literature) until May-2023. Only in vitro studies that evaluated the effects of CA on growth factors' release from dentin and cell behavior outcomes compared to EDTA were included. The studies were critically appraised using a modified Joanna Briggs Institute's checklist. Meta-analysis was unfeasible.

RESULTS

Out of the 335 articles screened, nine were included. Among these, three studies used dentin discs/roots from permanent human teeth; the rest combined them with stem cells. 10% CA for 5 or 10 minute was the most used protocol. Meanwhile, EDTA concentrations ranged from 10% to 17%. In eight studies examining the release of growth factors, five reported a significant release of transforming growth factor-β after dentin conditioning with 10% CA compared to 17% EDTA. Regarding cell behavior (6 studies), three studies assessed cell viability. The findings revealed that 10% CA conditioning showed cell viability similar to those of 17% EDTA. Additionally, in two out of three studies, it was observed that 10% CA conditioning did not affect cell morphology. The studies had a low risk of bias.

CONCLUSIONS

The use of 10% CA to condition dentin for 5-10 minutes resulted in a notable transforming growth factor -β1 release, but its cell responses were similar to those of EDTA.

Most systematic reviews reporting adherence to AMSTAR 2 had critically low methodological quality: a cross-sectional meta-research study

OBJECTIVES

To analyze the methodological quality and characteristics of systematic reviews (SRs) that reported they were conducted in line with the AMSTAR 2 (A MeaSurement Tool to Assess Systematic Reviews).

STUDY DESIGN AND SETTING

This was a cross-sectional meta-research study. We searched MEDLINE and Embase. We included full reports of SRs reporting the study was conducted, prepared, or designed in line with the AMSTAR 2. Eligible SRs were those published from January 1, 2018, until May 3, 2022. We assessed the methodological quality of the included SRs using AMSTAR 2.

RESULTS

We included a total of 45 records. There were 43 SRs and 2 SR protocols. Among them, most were SRs of interventions that included primary studies on humans. More than half had a meta-analysis. According to our overall AMSTAR 2 assessments of included SRs, 35 SRs were of critically low confidence, 7 SRs were of low confidence, and one SR was of high confidence. There were no SRs of moderate confidence.

CONCLUSION

Even when authors indicate in their manuscripts that the SR was conducted/prepared/designed in line with the AMSTAR 2, it does not necessarily imply it is of high or even moderate confidence according to AMSTAR 2. A self-assessment with AMSTAR 2 could be required for submission and carefully checked by the editors/peer reviewers.

Methodological quality of systematic reviews in dentistry including animal studies: a cross-sectional study

BACKGROUND

The overall confidence in the results of systematic reviews including animal models can be heterogeneous. We assessed the methodological quality of systematic reviews including animal models in dentistry as well as the overall confidence in the results of those systematic reviews.

MATERIAL & METHODS

PubMed, Web of Science and Scopus were searched for systematic reviews including animal studies in dentistry published later than January 2010 until 18th of July 2022. Overall confidence in the results was assessed using a modified version of the A MeaSurement Tool to Assess systematic Reviews (AMSTAR-2) checklist. Checklist items were rated as yes, partial yes, no and not applicable. Linear regression analysis was used to investigate associations between systematic review characteristics and the overall adherence to the AMSTAR-2 checklist. The overall confidence in the results was calculated based on the number of critical and non-critical weaknesses presented in the AMSTAR-2 items and rated as high, moderate, low and critical low.

RESULTS

Of initially 951 retrieved systematic reviews, 190 were included in the study. The overall confidence in the results was low in 43 (22.6%) and critically low in 133 (70.0%) systematic reviews. While some AMSTAR-2 items were regularly reported (e.g. conflict of interest, selection in duplicate), others were not (e.g.

FUNDING

n = 1; 0.5%). Multivariable linear regression analysis showed that the adherence scores of AMSTAR-2 was significantly associated with publication year, journal impact factor (IF), topic, and the use of tools to assess risk of bias (RoB) of the systematic reviews.

CONCLUSION

Although the methodological quality of dental systematic reviews of animal models improved over the years, it is still suboptimal. The overall confidence in the results was mostly low or critically low. Systematic reviews, which were published later, published in a journal with a higher IF, focused on non-surgery topics, and used at least one tool to assess RoB correlated with greater adherence to the AMSTAR-2 guidelines.

The methodological quality assessment of systematic reviews/meta-analyses of chronic prostatitis/chronic pelvic pain syndrome using AMSTAR2

BACKGROUND

This study aimed to assess the methodological quality of the systematic reviews/meta-analyses (SRs/MAs) of chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) using A Measurement Tool to Assess systematic Reviews (AMSTAR2) and to explore the potential influencing factors.

METHODS

PubMed, EMBASE and Cochrane Library databases were searched for relevant studies. AMSTAR2 was used for evaluating the methodological quality of eligible SRs/MAs. Differences between methodological characteristics of SRs/MAs were compared using chi-square tests. The intra-class correlation coefficient (ICC) was used to assess reviewer agreement in the pre-experiment. Multivariate regression analysis was used to identify potential factors affecting methodological quality.

RESULTS

A total of 45 SRs/MAs were included. After AMSTAR2 evaluation, only two (4.4%) of 45 SRs/MAs were moderate, three (6.7%) were rated as low quality, and the remainder 40 (88.9%) were rated as critically low quality. Among the 16 items of AMSTAR2, item 3 and item 10 had the poorest adherence. Item 4 received the most significant number of "Partial Yes" responses. Univariable analysis indicated that there were significant differences in methodological quality in SRs between different continents (P = 0.027) as well as between preregistered SRs and those that were not (P = 0.004). However, in multivariate analysis, there was no significant association between methodological quality and the following research characteristics: publication year, continent, whether reporting followed Preferred Reporting Items for Systematic Reviews (PRISMA), preregistration, funding support, randomized controlled trials (RCT) enrollment, whether SR was published in the Cochrane Database of Systematic Reviews (CDSR), and whether with meta-analysis. Additionally, subgroup analysis based on interventional SRs/MAs showed that continent was independently associated with the methodological quality of SRs/MAs of CP/CPPS via univariable and multivariate analysis.

CONCLUSIONS

Our study demonstrates that the methodological quality of SRs/MAs of CP/CPPS was generally poor. SRs/MAs of CP/CPPS should adopt the AMSTAR2 to enhance their methodological quality.

AMSTAR 2 is only partially applicable to systematic reviews of non-intervention studies: a meta-research study

OBJECTIVES

A measurement tool to assess systematic reviews 2 (AMSTAR 2) was originally developed for systematic reviews (SRs) of health-care interventions. The aim of this study was to assess the applicability of AMSTAR 2 to SRs of non-intervention studies.

STUDY DESIGN AND SETTING

This was a meta-research study. We used 20 SRs for each of the following four types of SRs: Diagnostic Test Accuracy reviews, Etiology and/or Risk reviews, Prevalence and/or Incidence reviews, and Prognostic reviews (80 in total). Three authors applied AMSTAR 2 independently to each included SRs. Then, the authors assessed the applicability of each item to that SR type and any SR type.

RESULTS

Researchers unanimously indicated that 7 of 16 AMSTAR 2 items were applicable for all four specific SR types and any SR type (items 2, 5, 6, 7, 10, 14 and 16), but 8 of 16 items for any SR type. These items could cover generic SR methods that do not depend on a specific SR type.

CONCLUSION

AMSTAR 2 is only partially applicable for non-intervention SRs. There is a need to adapt/extend AMSTAR 2 for SRs of non-intervention studies. Our study can help to further define generic methodological aspects shared across SR types and methodological expectations for non-intervention SRs.

Influence of sodium hypochlorite on cyclic fatigue resistance of nickel-titanium instruments: A systematic review and meta-analysis of in vitro studies

OBJECTIVE

This systematic review/meta-analysis investigated the influence of NaOCl on cyclic fatigue resistance of endodontic NiTi instruments.

MATERIALS AND METHODS

A systematic search until July 2022 in PubMed/MEDLINE, Embase, Scopus, Web of Science, SciELO, Cochrane Library, and grey literature was conducted. According to the PECOS strategy, only in vitro studies evaluating the effects of NaOCl on the cyclic fatigue resistance of NiTi instruments were eligible. Cyclic fatigue resistance was the primary outcome. A modified Joanna Briggs Institute's Checklist was used for risk of bias assessment.

RESULTS

Of the 2,445 records screened, 37 studies were included. Most studies used simulated canals made of stainless-steel block with severe to moderate curvatures. NaOCl concentration varied from 1-6%, mainly at 37 °C. Regarding fatigue resistance, 23 studies using 1.2% to 6% NaOCl showed a reduction in the resistance compared to the control groups, especially when pre-heated. Four meta-analyses were performed according to the tested NiTi systems. The meta-analyses indicated that the PTU F2 files had higher reduction of fatigue resistance after exposure to 5.25% NaOCl; no differences between NaOCl and no immersion were observed for Reciproc R25, WaveOne 25.08, and WaveOne Gold Primary files. Included studies had low risk of bias.

CONCLUSION

NaOCl appears to reduce cyclic fatigue resistance of certain NiTi files, especially when they are pre-heated, particularly in conventional NiTi files compared to some heat-treated instruments. It is possible that the temperature of the solution may have a greater influence on resistance than NaOCl itself. Important to note that an overall tendency toward no significant influence was observed among various systems.

CLINICAL RELEVANCE

Precautions are necessary when a pre-heated high-concentration NaOCl is used to enhance its properties during root canal preparation, mainly using conventional wire.

The relationship between methodological quality and the use of retracted publications in evidence syntheses

BACKGROUND

Evidence syntheses cite retracted publications. However, citation is not necessarily endorsement, as authors may be criticizing or refuting its findings. We investigated the sentiment of these citations-whether they were critical or supportive-and associations with the methodological quality of the evidence synthesis, reason for the retraction, and time between publication and retraction.

METHODS

Using a sample of 286 evidence syntheses containing 324 citations to retracted publications in the field of pharmacy, we used AMSTAR-2 to assess methodological quality. We used scite.ai and a human screener to determine citation sentiment. We conducted a Pearson's chi-square test to assess associations between citation sentiment, methodological quality, and reason for retraction, and one-way ANOVAs to investigate association between time, methodological quality, and citation sentiment.

RESULTS

Almost 70% of the evidence syntheses in our sample were of critically low quality. We found that these critically low-quality evidence syntheses were more associated with positive statements while high-quality evidence syntheses were more associated with negative citation of retracted publications. In our sample of 324 citations, 20.4% of citations to retracted publications noted that the publication had been retracted.

CONCLUSION

The association between high-quality evidence syntheses and recognition of a publication's retracted status may indicate that best practices are sufficient. However, the volume of critically low-quality evidence syntheses ultimately perpetuates the citation of retracted publications with no indication of their retracted status. Strengthening journal requirements around the quality of evidence syntheses may lessen the inappropriate citation of retracted publications.

Fracture Resistance of Fiber-Reinforced Composite Restorations: A Systematic Review and Meta-Analysis

Composite resin is universally used for posterior teeth restorations. Fibers have been suggested for the mechanical improvement of the restorations. This study assessed the fracture resistance of class II fiber-reinforced composite restorations and compared it with the fracture resistance of three control groups: (1) healthy teeth, (2) non-fiber-reinforced restorations and (3) unrestored cavities. A search was performed using PubMed, Web of Science and Google Scholar from 15 May to 12 June 2023. Only in vitro studies from the last 10 years were included for this systematic analysis. This study was registered in the PROSPERO database, it followed PRISMA guidelines and the risk of bias was assessed using the QUIN tool. Fracture resistance median values, in Newtons (N), were calculated for the experimental and control groups (95% confidence interval). For pairwise comparison, nonparametric tests (p < 0.05) were applied. Twenty-four in vitro studies met the inclusion criteria. The fracture resistance of the experimental group was 976.0 N and differed (p < 0.05) from all controls. The experimental group showed lower values of fracture resistance than healthy teeth (1459.9 N; p = 0.048) but higher values than non-fiber-reinforced restorations (771.0 N; p = 0.008) and unrestored cavities (386.6 N; p < 0.001). In vitro systematic outcomes evidenced that glass and/or polyethylene fibers improved the fracture resistance of composite restorations.

Tooth color change after photodynamic therapy in endodontics: a systematic review

BACKGROUND

A smile is considered one of the most important soft skills in social interaction. It is known that some photosensitizer agents (PS) used in photodynamic therapy (PDT) during root canal treatment could play a significant role in tooth color change, and thus the main objective of this systematic review is to address whether performing PDT can influence tooth color change and to synthesize the most effective methods to remove PS from the root canal system.

METHODS

This study followed the PRISMA 2020 statement, and the protocol was registered at the Open Science Framework. Two blinded reviewers searched five databases up to November 20^th, 2022: Web of Science, PubMed, Scopus, Embase, and the Cochrane Library. The eligibility criteria were studies that investigated tooth color change after PDT in endodontics.

RESULTS

A total of 1695 studies were retrieved, and 7 were included in the qualitative analysis. All the included studies were in vitro evidence and investigated five different PS: methylene blue, toluidine blue O, malachite green, indocyanine green, and curcumin. Besides curcumin and indocyanine green, the remaining agents all caused tooth color change, and no method employed was effective in fully removing these PS from inside the root canal system CONCLUSIONS: Even though the findings showed that curcumin and indocyanine green did not influence tooth color change, the present evidence should be interpreted with caution since it is based on laboratory studies with questionable methods, and all efforts should be employed to avoid this undesirable side effect during clinical practice.

Sol-gel synthesis of lithium doped mesoporous bioactive glass nanoparticles and tricalcium silicate for restorative dentistry: Comparative investigation of physico-chemical structure, antibacterial susceptibility and biocompatibility

Introduction: The sol-gel method for production of mesoporous bioactive glass nanoparticles (MBGNs) has been adapted to synthesize tricalcium silicate (TCS) particles which, when formulated with other additives, form the gold standard for dentine-pulp complex regeneration. Comparison of TCS and MBGNs obtained by sol-gel method is critical considering the results of the first ever clinical trials of sol-gel BAG as pulpotomy materials in children. Moreover, although lithium (Li) based glass ceramics have been long used as dental prostheses materials, doping of Li ion into MBGNs for targeted dental applications is yet to be investigated. The fact that lithium chloride benefits pulp regeneration in vitro also makes this a worthwhile undertaking. Therefore, this study aimed to synthesize TCS and MBGNs doped with Li by sol-gel method, and perform comparative characterizations of the obtained particles.

Methods: TCS particles and MBGNs containing 0%, 5%, 10% and 20% Li were synthesized and particle morphology and chemical structure determined. Powder concentrations of 15mg/10 mL were incubated in artificial saliva (AS), Hank’s balanced saline solution (HBSS) and simulated body fluid (SBF), at 37°C for 28 days and pH evolution and apatite formation, monitored. Bactericidal effects against S. aureus and E. coli, as well as possible cytotoxicity against MG63 cells were also evaluated through turbidity measurements.

Results: MBGNs were confirmed to be mesoporous spheres ranging in size from 123 nm to 194 nm, while TCS formed irregular nano-structured agglomerates whose size was generally larger and variable. From ICP-OES data, extremely low Li ion incorporation into MBGNs was detected. All particles had an alkalinizing effect on all immersion media, but TCS elevated pH the most. SBF resulted in apatite formation for all particle types as early as 3 days, but TCS appears to be the only particle to form apatite in AS at a similar period. Although all particles had an effect on both bacteria, this was pronounced for undoped MBGNs. Whereas all particles are biocompatible, MBGNs showed better antimicrobial properties while TCS particles were associated with greater bioactivity.

Conclusion: Synergizing these effects in dental biomaterials may be a worthwhile undertaking and realistic data on bioactive compounds targeting dental application may be obtained by varying the immersion media.