INFLUENCE OF PROTAPER FINISHING FILES AND SODIUM HYPOCHLORITE ON CLEANING AND SHAPING OF MANDIBULAR CENTRAL INCISORS – A HISTOLOGICAL ANALYSIS

Objective:

This study investigated the influence of the last apical instrument of the ProTaper system with and without 2.5% sodium hypochlorite for cleaning mandibular central incisors.

Material and Methods:

Thirty two mandibular central incisors were divided into six study groups: Group I – F1 instrument with 2.5% sodium hypochlorite; Group II – F1 and F2 with 2.5% sodium hypochlorite; Group III – F1, F2 and F3 with 2.5% sodium hypochlorite; Group IV – F1 with distilled water; Group V – F1 and F2 with distilled water; Group VI – F1, F2 and F3 with distilled water. The two remaining teeth comprised the negative control group. The specimens were prepared following the principles of the technique suggested by the manufacturer and then submitted to histological preparation and morphometric analysis. Data were analyzed statistically by the Kruskal Wallis test at 1% significance level.

Results:

There was statistically significant difference (p<0.01) between all study groups, except between Groups I and VI.

Conclusions:

It was concluded that no technique allowed complete cleaning of the root canals. However, the technique of finishing preparation of the apical third with the F3 instrument with 2.5% sodium hypochlorite irrigation was the most effective.     

SUGAR-FREE CHEWING GUM AND DENTAL CARIES – A SYSTEMATIC REVIEW

Objective:

To appraise existing evidence for a therapeutic / anti-cariogenic effect of sugar-free chewing gum for patients.

Method:

9 English and 2 Portuguese databases were searched using English and Portuguese keywords. Relevant articles in English, German, Portuguese and Spanish were included for review. Trials were excluded on lack of randomisation, control group, blinding and baseline data, drop out rate >33%, no statistical adjustment of baseline differences and no assessment of clinically important outcomes. Reviews were excluded on lack of information, article selection criteria, search strategy followed, search keywords, searched databases or lack of study-by-study critique tables. In cases of multiple reports from the same study, the report covering the longest period was included. Two reviewers independently reviewed and assessed the quality of accepted articles.

Results:

Thirty-nine articles were included for review. Thirty were excluded and 9 accepted. Of the 9 accepted, 2 trials of reasonable and good evidence value did not demonstrate any anti-cariogenic effect of sugar-free chewing gum. However, 7 articles, with 1 of strong, and 6 of good evidence value, demonstrated anti-cariogenic effects of chewing Sorbitol, Xylitol or Sorbitol/Xylitol gum. This effect can be ascribed to saliva stimulation through the chewing process, particularly when gum is used immediately after meals; the lack of sucrose and the inability of bacteria to metabolize polyols into acids.

Conclusion:

The evidence suggests that sugar-free chewing gum has a caries-reducing effect. Further well-designed randomised trials are needed to confirm these findings.     

RISK PREDICTORS OF EARLY CHILDHOOD CARIES INCREMENT—A SYSTEMATIC REVIEW AND META-ANALYSIS

This systematic review aimed to investigate the risk predictors of caries in primary teeth and evaluate their association with the increment of Early Childhood Caries (ECC) among preschool children. This systematic review included only cohort or case-control studies of at least 2 years duration, over 300 participants and with English full-text. Potentially eligible studies were retrieved from 4 electronic databases (Ovid Embase, Ovid MEDLINE; PubMed, Web of Science) from inception to March 1, 2021. Independent screening and data extraction by 2 reviewers to identify factors associated with ECC increment, including family and socioeconomic factors, dietary and oral health-related habits, and clinical parameters. A total of 18 studies from 163 potential reports were included, involving 1,159,226 preschool children. Lower parental education attainment was found associated with ECC increment (WMD:0.87; 95% CI 0.52, 1.21); whereas immigration status (WMD:-0.38; 95% CI -1.09, 0.34), gender (WMD:-0.02; 95% CI -0.28, 0.24), and dental service utilization (WMD:0.35; 95% CI -0.10, 0.79) were not significant factors for ECC increment. All included studies consistently suggested positive correlations between ECC increment and baseline caries experience, plaque level, cariogenic microorganisms, and prenatal and passive smoking, while mixed findings were detected between ECC increment with dietary and oral hygiene practices. Preschool children whose parents have low education level are more likely to have greater increment of ECC over 2 years. Existing caries lesions, increased dental plaque level, cariogenic microorganisms, prenatal or passive smoking were also consistently identified as risk factors for ECC in all reviewed studies. This systematic review highlights specific risk factors to target for the prevention of ECC and supports implementing more oral health promotion for preschool children with parents of lower educational attainment.     

EFFICACY OF SODIUM HYPOCHLORITE AND CHLORHEXIDINE AGAINST Enterococcus faecalis – A SYSTEMATIC REVIEW

The efficacy of the sodium hypochlorite (NaOCl) and chlorhexidine (CHX) on Enterococcus faecalis was evaluated by systematic review and meta-analysis. The search strategies included search in electronic biomedical journal databases (MEDLINE, EMBASE, CENTRAL) and handsearching records, using different matches of keywords for NaOCl, CHX and Enterococcus faecalis. From 41 in vivo studies, 5 studies met the inclusion criteria. In a sample containing 159 teeth, E. faecalis was detected initially in 16 (10%) teeth by polymerase chain reaction (PCR) and 42 (26.4%) teeth by microbial culture techniques. After root canal disinfection, this species was observed in 11 (6.9%) teeth by PCR and 12 (7.5%) teeth by culture. Risk differences of included studies were combined as generic inverse variance data type (Review Manager Version 5.0 – Cochrane Collaboration, http://www.cc-ims.net, accessed 15 May 2008), taking into account the separate tracking of positive and negative cultures/PCR. The level of statistical significance was set at p<0.05. In conclusion, NaOCl or CHX showed low ability to eliminate E. faecalis when evaluated by either PCR or culture techniques.     

DOES TITANIUM TETRAFLUORIDE PROMOTE A PROTECTIVE EFFECT ON ERODED TOOTH? A SYSTEMATIC REVIEW AND META-ANALYSIS

ObjectiveThis systematic review and meta-analyses aimed to evaluate the potential protective effect of titanium tetrafluoride (TiF₄) compound compared to sodium fluoride (NaF) on eroded enamel or dentin.MethodsTwo independent reviewers searched PubMed, Scopus, Web of Science, LILACS, Cochrane, EMBASE, and Open gray Literature up to June 2020. MeSH terms, supplementary concepts, synonyms, and free terms were applied based on PICOS strategy (P- population: eroded enamel or dentin; I- intervention: eroded teeth treated with solution or varnish of TiF₄; C- comparison: eroded teeth treated with a solution or varnish of NaF; O- outcome: mineral loss measurement; S- study design: in vitro studies). Seven distinct parameters evaluated the risk of bias, and all studies were submitted to 4 meta-analyses (first and second meta-analyses related to enamel loss treated with fluoride solution or varnish, respectively; third and fourth meta-analyses related to dentin loss treated with fluoride solution or varnish, respectively). A sensitivity test was performed by the RevMan software, based on standard mean difference calculation (P < .05).ResultsA total of 10,260 studies were retrieved, from which 22 studies were included in systematic review through eligibility criteria, of which 1 study was classified as low risk of bias, 19 as medium, and 3 as high. Seventeen studies were included in 4 different meta-analyses, presenting considerable overall heterogeneity (I² = 95; 92; 95; and 93%, respectively) with statistical significance for TiF₄ on the first meta-analysis, and no statistical significance for second, third, and fourth meta-analyses.ConclusionsTitanium tetrafluoride compound delivered as solution provided significant effective protection for erosion lesions on the enamel surface compared to sodium fluoride. However, when TiF₄ or NaF were applied on enamel or dentin surfaces as varnish, both provided the same effective protection, based on in vitro studies with considerable heterogeneity.     

FISSURE SEALANT IN A NUTSHELL. EVIDENCE-BASED META-EVALUATION OF SEALANTS’ EFFECTIVENESS IN CARIES PREVENTION AND ARREST

ObjectiveThis meta-evaluation aimed to summarize all available evidence regarding different fissure sealants on occlusal caries prevention, arrest, retention rate, adverse effect, and cost-effectiveness; when compared with no intervention, other preventive or minimally-invasive procedures.Materials and MethodsThe systematic reviews and meta-analyses were identified via four electronic databases and manual searching. Two independent reviewers performed study selection, data extraction, quality assessment with AMSTAR-2.ResultsAmong the 366 records yielded, 38 systematic reviews were identified as eligible 24 of them included meta-analyses. Moderate evidence has supported the efficacies of resin-based sealants (RBS) in occlusal caries prevention, arrest and cost-effectiveness compared to no interventions. Low to very low certainty of evidence suggested similar effectiveness of glass-ionomer cements in caries prevention with RBS and more superior performance of resin infiltration in arresting non-cavitated occlusal lesions.ConclusionThis meta-evaluation supports the use of RBS on permanent molars to reduce occlusal caries occurrence, arrest lesion progression and alleviate oral health inequalities between individuals of different socioeconomic status. This meta-evaluation also advocates further research on glass-ionomer cements and resin infiltration with respect to their efficacies in caries prevention and arrest.