Applying basic math to periodontal decision-making.

Evidence-based dentistry involves making the best decision for patient care when presented with uncertainty and choice. Biostatistical tools help measure and analyze the level of uncertainty so that dentists can make confident clinical decisions concerning individual patient care. Biostatistical analysis complemented with the GRADE (Grading of Recommendations, Assessment, Development and Evaluations) tool can assist clinicians in transferring evidence to clinical practice.

Not all Desensitizing Toothpastes Perform Equally Well.

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION: Network Meta-Analysis on the Effect of Desensitizing Toothpastes on Dentine Hypersensitivity. Hu ML, Zheng G, Lin H, Yang M, Zhang YD, Han JM. J Dent 2019;88:103170. SOURCE OF FUNDING: National Natural Science Foundation of China (81771119). TYPE OF STUDY/DESIGN: Systematic review with meta-analysis of data.

Cold pulp testing is the simplest and most accurate of all dental pulp sensibility tests.

Data sources PubMed, Scopus and Web of Science.Study selection Cohort (retrospective and prospective) and cross-sectional clinical studies investigating the diagnostic accuracy of the cold pulp test (CPT), heat pulp test (HPT), electric pulp test (EPT), laser Doppler flowmetry (LDF) and pulp oximeter (PO). Pulpal diagnosis was confirmed by histological analysis, direct clinical observations (access cavity) or evidence of root canal filling (to confirm nonvital teeth).Data extraction and synthesis The diagnostic test's sensitivity (Sn), specificity (Sp), accuracy, positive predictive value (PPV) and negative predictive value (NPV) were extracted or calculated from the raw data of each included study. The test's outcomes were binary. A true positive (TP) was considered to have occurred when the diagnostic instrument correctly tested positive for a non-vital pulp and true negative (TN) when it correctly tested negative for a vital pulp based on a standard reference test. A false positive (FP) and false negative (FN) occurred when the test incorrectly tested positive on a vital pulp and incorrectly tested negative on a non-vital pulp, respectively. Accuracy, PPV and NPV were adjusted (Adj.Accuracy, Adj.PPV and Adj.NPV respectively) based on a standardised total disease (non-vital pulps) prevalence (Prev.) of 42.8%. Pool estimates for all five dental pulp vitality diagnostic variables (Sn, Sp, Adj.Accuracy, Adj.PPV and Adj.NPV) were generated with a meta-analysis using a random effects model. Included studies were assessed as either high, moderate or low quality based on the Quality Assessment of Diagnostic Accuracy Studies tool.Results Twenty-eight studies met the inclusion criteria. The pooled Sn, Sp, Adj.Accuracy, Adj.PPV and Adj.NPV for each test are given in the Table 1. Heterogeneity between studies was significant for CPT, HPT and EPT; it was mild to moderate for LDF and PO. All but three studies were determined to be of low quality, with only one assessed as high quality.Conclusions The most accurate dental pulp tests are the LDF and PO, with the HPT least accurate. CPT has generally high diagnostic accuracy and can be considered the primary pulp testing method in clinical practice.

Managing post endodontic treatment pain by eliminating occlusal contacts.

Data sources Forty-four adult patients (32 female : 12 males) with irreversible pulpitis with periapical periodontitis on a mandibular posterior tooth, who were undergoing a two-visit endodontic treatment protocol, were randomly divided into two groups. The intervention group (n = 22) had occlusal surface reduced on the treated tooth and a control group (n = 22) did not.Data The primary outcome was pain intensity after endodontic treament, which was measured on a visual-analogue-scale (VAS). This was measured 6, 12, 24 and 48 hours after the first visit, and 6, then 12 hours after the second visit.The study also investigated the proportion of patients who took post-operative analgesic tablets.Results Pain intensity 12 hours after the first and second visits were statistically significantly lower in the intervention group compared to the control group. The proportion of patients who recorded taking analgesics was not significantly different between the two groups.Conclusions Occlusal reduction seems to reduce levels of post root- treatment pain in posterior mandibular teeth 12 hours postopertively, but otherwise makes little difference.

Laser Therapy has Minimal Clinical Efficacy at Reducing Postsurgical Complications After the Removal of Impacted Mandibular Third Molars.

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION: Efficacy of adjuvant laser therapy in reducing postsurgical complications after the removal of impacted mandibular third molars: A systematic review update and meta-analysis. Dawdy J, Halladay J, Carrasco-Labra A, Araya I, Yanine N, Brignardello-Petersen R. J Am Dent Assoc 2017;148(12):887-902.e884. SOURCE OF FUNDING: None of the authors reported any disclosures TYPE OF STUDY/DESIGN: Systematic review with meta-analysis of data.

Caries risk and number of restored surfaces have impact on the survival of posterior composite restorations.

DATA SOURCES: Cochrane Library, PubMed, the Web of Science (ISI) and Scopus. STUDY SELECTION: Longitudinal studies of direct class II or classes I and II restorations in permanent dentition of at least five years duration, a minimum of 20 restorations at final recall and the original datasets available were considered. Only English language studies were included. Two reviewers screened titles independently. DATA EXTRACTION AND SYNTHESIS: Multivariate Cox regression method to analyse the variables of interest and hazard ratios with respective 95% confidence intervals were determined. The annual failure rate (AFR) of the investigated restorations and subgroups was calculated. RESULTS: Twelve studies, nine prospective and three retrospective were included. A total of 2,816 restorations (2,585 Class II and 231 Class I restorations) were included in the analysis. Five hundred and sixty-nine restorations failed during the observation period, and the main reasons for failure were caries and fracture. Regression analyses showed a significantly higher risk of failure for restorations in high-caries-risk individuals and those with a higher number of restored surfaces. The overall annual failure rate at five years and ten years was 1.8% and 2.4% respectively. The rates were higher in high-caries-rate individuals at 3.2% and 4.6% respectively. CONCLUSIONS: The conclusion of the present meta-analysis of 12 clinical studies based on raw data is that caries risk and number of restored surfaces play a significant role in restoration survival, and that, on average, posterior resin composite restorations show a good survival, with annual failure rates of 1.8% at five years and 2.4% after ten years of service.

Defective amalgam restorations--repair or replace?

DATA SOURCES: The Cochrane Oral Health Group's Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), Medline, Embase, BIOSIS via Web of Knowledge, Web of Science and Opengrey databases were searched. In addition researchers and experts in the field were contacted to trace unpublished or ongoing studies. No restrictions were placed on the language or date of publication. STUDY SELECTION: Randomised controlled trials (including split-mouth studies), involving replacement and repair of amalgam restorations in adults with a defective molar restoration in permanent molar or premolar teeth were to be considered. DATA EXTRACTION AND SYNTHESIS: Two review authors independently assessed titles and abstracts for each article identified by the searches in order to decide whether the article was likely to be relevant. Full papers were obtained for relevant articles and both review authors studied these. The Cochrane Collaboration statistical guidelines were to be followed for data synthesis. RESULTS: The search strategy retrieved 201 potentially eligible studies after de-duplication. After examination of the titles and abstracts, full texts of the relevant studies were retrieved but none of these met the inclusion criteria of the review. CONCLUSIONS: There are no published randomised controlled trials relevant to this review question. There is therefore a need for methodologically sound randomised controlled trials that are reported according to the Consolidated Standards of Reporting Trials (CONSORT) statement (www.consort-statement.org/). Further research also needs to explore qualitatively the views of patients on repairing versus replacement and investigate themes around pain, distress and anxiety, time and costs.

Limited evidence on the best position for prosthetic margins.

DATA SOURCES: The Cochrane Central Register of Controlled Trials (CENTRAL), Cochrane Database of Systematic reviews, Medline, Google Scholar and Scopus databases were searched along with handsearching of the Journal of Prosthetic Dentistry, International Journal of Prosthodontics, Journal of Dentistry and Caries Research. STUDY SELECTION: Randomised controlled clinical trials, prospective or retrospective studies or case-control observational studies reporting on caries susceptibility of teeth serving as abutments for prosthetic restorations were included. Only English language studies were included. DATA EXTRACTION AND SYNTHESIS: Study selection and quality assessment was carried out by two reviewers. Trials were compared by grouping abutments teeth/abutment surfaces with subgingival margins. Caries incidence was evaluated as a dichotomous variable. The risk ratio (RR) for caries incidence of prosthetic margins was calculated for the direct comparisons and pooled using a random-effects model. The overall quality of evidence supporting the association between secondary caries and margin placement was assessed using the GRADE system. RESULTS: Twenty-two studies were included, representing 2,648 prosthetic restorations placed in 1,242 patients with mean follow-up time ranging from two to 11.4 years. A random effects meta-analysis was performed on two studies. This found a pooled risk ratio (RR) for secondary caries of sub-gingival margins at up to five years of 1.25 (95% CI: 0.70 to 2.22). At ten years of follow-up, the RR was1.22 (95% CI: 0.81 to 1.83) and at 15 years 0.67 (95% CI: 0.45 to 1.00). CONCLUSIONS: This systematic review and meta-analysis failed to detect a significantly different secondary caries rate of subgingivally located prosthetic margins in the short to mid-term (10 years). Due to the small number and the limitations of the included studies the results do not provide conclusive evidence as to the effect of prosthetic margin placement on the incidence of secondary caries.

Cast or fiber posts a summary of evidence from vitro studies.

DATA SOURCES: Medline, the Cochrane Controlled Trials Register, China National Knowledge Infrastructure and China Biology Medicine disc were searched. STUDY SELECTION: Only randomised studies were included. DATA EXTRACTION AND SYNTHESIS: Data were independently extracted. Standardised mean differences were combined and analysed using meta-analysis. RESULTS: Thirteen studies were included; premolars were used as specimens in six studies, central incisors in five studies and canines in three articles. There was considerable variation in both alloy and fibre materials used between studies. The standardised mean difference of the combined data was 0.64 (95% confidence interval, 0.08-1.20; P < .001), indicating that the cast post group displayed significantly higher fracture resistance than the fibre post group. CONCLUSIONS: On the basis of the current best available evidence, we concluded that cast posts had higher fracture resistance than fibre posts.

Periodontally involved teeth - extract or not?

DESIGN: Decision analysis modelling. METHOD: The authors created a scenario in which a patient with a periodontally involved tooth was referred for a decision to be made over whether to extract the tooth or not. Neighbouring teeth were healthy. A decision tree that included no treatment, periodontal treatment, extraction and replacement with fixed partial denture, and extraction with single implant was created. It was populated with 'objective' probability data from systematic reviews and 'subjective' probability data from clinicians. No patient preference data were included. Eligible studies had to have a follow-up of ≥5 years. Four 'senior experts' including three periodontists and one prosthodontist evaluated a quantitative measure of the strength of the preference for an outcome. OUTCOME MEASURE: Expected utility (EU) of each management approach on a scale of 0-100. RESULTS: The EU could not be calculated for the no treatment option owing to lack of probability data (ie no-one has followed up patients who do not receive periodontal treatment). For the periodontal treatment, FPD and implant groups the respective EU intervals over five years were 79-96, 86-89 and 94-95. CONCLUSIONS: The EU intervals suggest the implant option is better than the FPD option if the tooth is extracted, but it is unclear whether periodontal treatment or extraction and implant is best.

Industry sponsored research may report more favourable outcomes.

DATA SOURCES: Medline and the Cochrane Database of systematic reviews between January 1993 and December 2008. Hand search of 12 different dental journals (Journal of Periodontology, International Dental Journal, British Dental Journal, Journal of the International Academy of Periodontology, Journal Canadian Dental Association, Swedish Dental Journal, Quintessence International, Journal of Clinical Periodontology, Periodontology 2000, Clinical Oral Implant Research, International Journal of Oral and Maxillofacial Implants, International Journal of Prosthodontic, Journal of Prosthetic Dentistry). Language restricted to English. STUDY SELECTION: Primary articles from systematic reviews that specifically studied the length of survival of dental implants. DATA EXTRACTION AND SYNTHESIS: Primary studies were extracted from reviews for which the following information was available: the failure rate of dental implants, publication year, journal Impact Factor, prosthetic design periodontal status, number of dental implants included in the study, methodological quality of studies, presence of a statistical advisor and financial sponsorship. Univariant quasi-Poisson regression and multivariate analysis were used to identity variables that were significantly associated with failure rates. RESULTS: Two independent reviewers identified five systematic reviews from which 41 analysable trials were extracted (Kappa 0.90; 95%CI 0.77 - 1.00). The mean annual failure rate estimate for all trials was 1.09% (95%CI 0.84 - 1.42). The mean annual failure rate estimate of non-industry funded trials was 2.74% (95%CI 1.14 - 6.55). Four trials (10%) reported non-industry funding sources. The funding source was not reported in 26 trials (63%). 27 trials (66%) were considered to have a risk of bias. Given study age, both industry associated (OR= 0.21; 95%CI 0.12 - 0.38) and unknown funding sources trials (OR = 0.33; 95%CI 0.21 - 0.51) had a lower annual failure rate compared with non-industry associated trials. A conflict of interest statement was provided in 2 trials (5%). CONCLUSIONS: After controlling for other factors, the probability of annual implant failure reported in industry associated trials is significantly lower compared with non-industry associated trials. This bias may have significant impact on tooth extraction decision making, research on tooth preservation and government health care policies.

Implant-supported cantilevered fixed partial dentures.

DATA SOURCES: Medline was used to search for relevant material for the review. STUDY SELECTION: Systematic reviews and longitudinal prospective/ retrospective studies (randomised controlled trials, controlled clinical trials and cohort studies) were chosen that reported outcomes following treatment with implant-supported fixed partial denture prostheses (FPDP) with cantilever extensions, after a mean function time of at least 5 years. Two independent reviewers preformed screening and data abstraction. DATA EXTRACTION AND SYNTHESIS: Five-year survival and technical complication rates were extracted, which included: loss of prosthesis, loss of implants, complications with supra-construction (fractures or deformations of the framework or veneers, loss of retention and screw or abutment loosening) and marginal bone loss. Data from included studies were pooled and summarised as a weighted mean. Disagreement regarding data extraction was resolved by discussion and consensus. RESULTS: Only three studies met the inclusion criteria for final analysis. Two of the studies had a prospective or retrospective case-control design, whereas the third was a prospective cohort study. The 5-year survival rate of cantilever FPDP varied between 89.9 and 92.7% (weighted mean, 91.9%), with implant fracture as the main cause for failure. The corresponding survival rate for FPDP without cantilever extensions was 95.3 to 96.2% (weighted mean, 95.8%). Technical complications related to the supra-construction in the three included studies were reported to occur at a frequency of 13-26% (weighted mean, 20.3%) for cantilever FPDP, compared with 0-12% (weighted mean, 9.7%) for noncantilever FPDP. The most common complications were minor porcelain fractures and bridge-screw loosening. For cantilever FPDP, the 5-year event-free survival rate varied between 66.7 and 79.2% (weighted mean, 71.7%) and between 83.1 and 96.3% (weighted mean, 85.9%) for noncantilever FPDP. No statistically significant differences were reported with regard to peri-implant bone-level change between the two prosthetic groups, either at the prosthesis or at the implant level. CONCLUSIONS: Data on implant-supported FPDP with cantilever extensions are limited and therefore survival and complication rates should be interpreted with caution. The incorporation of cantilevers into implant-borne prostheses may be associated with a higher incidence of minor technical complications.

Fine-hybrid and nanohybrid restorative materials show similar durability in Class II cavities.

DESIGN: This was a randomised trial. INTERVENTION: Individuals who required a minimum of two replacement fillings were recruited. Restorations were placed using either Grandio bonded with Solobond M (Voco, Cuxhaven, Germany) or Tetric Ceram bonded with Syntac (Ivoclar Vivadent, Schaan, Liechtenstein). OUTCOME MEASURE: At the initial recall (baseline, ie, within 2 weeks), and after 6 months, 1 and 2 years, all restorations were assessed according to the modified United States Public Health Service (US PHS) criteria by two independent investigators using mirrors, probes, bitewing radiographs, impressions and intra-oral photographs. Recall assessments were not performed by the clinician who initially placed the restorations. RESULTS: Both recall rate and survival rate were 100% after 4 years of clinical service. No significant difference was found between the restorative materials. Hypersensitivities were significantly reduced over time (P < 0.05; Friedman test). A significant deterioration over time was found for the criteria of marginal integrity (66% sufficient after 4 years),tooth integrity (15% sufficient), filling integrity (73% sufficient) and proximal contact. Stereo light microscopy and scanning electron microscopy (SEM) analysis of restoration margins revealed differences in the amount of perfect margins in favour of Tetric Ceram (P <0.05). CONCLUSIONS: Both materials performed satisfactorily over the 4-year observation period. Because of the extension of the restorations, wear was clearly visible after 4 years of clinical service with 50% sufficient ratings.

Simple Approaches for Establishing an Evidence-Based Dental Practice.

Constructing an evidence-based dental practice requires leadership, commitment, technology support, and time, as well as skill practice in searching, appraising, and organizing evidence. In mastering the skills of evidence-based dentistry, clinicians can implement high-quality science into practice through a variety of opportunities including the development of clinical care guidelines, procedural technique protocols, and electronic dental record auto-note templates, as well as treatment planning, care prioritization, and case presentation. The benefits of building an evidence-based dental practice are many, including improvements in patient care and satisfaction, increased treatment predictability and confidence in care approaches, as well as potential cost savings.

Root canal therapy, fixed partial dentures and implant-supported crowns, have similar short term survival rates.

DATA SOURCES: Searches using the Medline, Cochrane and Embase databases and 'citation mining' (identifying references from included studies) were carried out. In addition, experts' recommendations for data sources were followed, and the table of contents of every issue of the most recent 2 years of a given list of dental journals were reviewed, the latter representing half of the total number of original research articles in English from the past 5 years on implant-supported crown (ISC), fixed partial dentures (FPD) and root canal (RC) therapy. Publication language was limited to English and grey literature was excluded, namely proceedings of conferences not listed in Medline, Cochrane or Embase databases, meetings and lectures. STUDY SELECTION: Comparative or noncomparative, prospective or retrospective longitudinal data were selected that related to clinical, biological, psychological and economic outcomes, as well as beneficial or harmful effects, of saving teeth by root canal treatment and/or alternative treatments, including: extracting the tooth and leaving an edentulous space or replacing the missing tooth with a fixed-partial-denture or implant-supported tooth. DATA EXTRACTION AND SYNTHESIS: Three pairs of investigators (each team dealing with one of the three main treatment options) independently searched, selected and extracted data for analysis. Tables of evidence were created from articles that met the validity criteria. Each selected paper was given a quality score, where the maximum possible was 17. Discussion and consensus were used to resolve disagreement. Interpretation of the outcome data and classification of data according to success or survival and the type of study were verified by two statisticians. Qualitative and quantitative methods were used to integrate the evidence. The data were analysed by deciding whether and what data to combine, and measuring the statistical heterogeneity of the data using Cochrane Q and I statistics. For the purpose of comparison, clinical outcomes were grouped into three time-intervals (2-4 years, 4-6 years and >6 years). Each discipline and followup interval from individual studies were displayed in a Forest plot with Wilson Score 95% confidence intervals. Meta-analysis produced pooled points and weighted averages. Psychosocial and economic outcome data was subjected to narrative review only. RESULTS: The 143 selected studies varied considerably in design, definition of success, assessment methods, operator type and sample size. Direct comparison of treatment types was extremely rare. Limited psychosocial data revealed the traumatic effect of loss of visible teeth. Economic data were largely absent. Success rates for ISC were higher than for RC treatment with direct or indirect restoration and FPD, respectively. Success criteria, however, differed greatly between treatment types, rendering direct comparison of success rates futile. Long-term survival rates for ISC and RC therapy were similar and superior to those for FPD. CONCLUSIONS: The lack of studies with similar outcome criteria and comparable time intervals limited the ability to make valid comparisons between these treatments. It was possible to conclude that ISC and RC treatments have superior long-term survival compared with FPD. Limited data suggested that extraction without replacement resulted in inferior psychosocial outcomes compared with alternatives. Long-term prospective clinical trials with large sample sizes and clearly defined outcome criteria are needed.

No difference in the 5-year survival rates between the resin-bonded cantilever bridge and the removable partial denture for the restoration of the shortened dental arch.

DESIGN: This was a randomised controlled trial (RCT) in a dental hospital. INTERVENTION: Resin-bonded fixed partial dentures (RBFPD) or removable partial dentures (RPD) were compared. The RBFPD restored 1 occlusal unit, up to but not beyond the second premolar, by means of single pontics cantilevered from single abutments whenever possible. Bilateral lower free-end saddle RPD were constructed on cast metal frameworks that incorporated rests, retainers and a rigid connector. The trial's participants were reviewed 3 months and 1 year after insertion of the new lower prosthesis, and thereafter at yearly intervals. Additional review and maintenance appointments were scheduled as clinically required. OUTCOME MEASURE: Survival of the prosthesis was assessed at each review according to specified criteria. Survival analysis was performed using a Cox proportional hazard regression ratio. RESULTS: Eleven fixed partial dentures and 15 RPD failed. Debonding was the most common cause of failure in the RBFPD group, with non-use and loss of teeth most common in the RPD group. Although the RPD group required rather more maintenance visits, the difference in prosthesis survival rates was not statistically significant [hazard ratio (HR), 0.59; 95% confidence intervals (CI), 0.27-1.29]. CONCLUSIONS: The absence of a significant difference in 5-year survival, the reported advantages of fixed partial dentures, and the greater maintenance need for those in the RPD treatment group support the use of RBFPD.

Do preoperative antibiotics prevent dental implant complications?

DATA SOURCES: The Cochrane Oral Health Group's Trials Registry, the Cochrane Central Register of Controlled Trials, Medline and Embase were consulted to find relevant work. Searches were made by hand of numerous journals pertinent to oral implantology. There were no language restrictions. STUDY SELECTION: Randomised controlled clinical trials (RCT) with a followup of at least 3 months were chosen. Outcome measures were prosthesis failures, implant failures, postoperative infections and adverse events (gastrointestinal, hypersensitivity, etc.). DATA EXTRACTION AND SYNTHESIS: Two reviewers independently assessed the quality and extracted relevant data from included studies. The estimated effect of the intervention was expressed as a risk ratio together with its 95% confidence interval (CI). Numbers-needed-to-treat (NNT) were calculated from numbers of patients affected by implant failures. Meta-analysis was done only if there were studies with similar comparisons that reported the same outcome measure. Significance of any discrepancies between studies was assessed by means of the Cochran's test for heterogeneity and the I2 statistic. RESULTS: Only two RCT met the inclusion criteria. Meta-analysis of these two trials showed a statistically significantly higher number of patients experiencing implant failures in the group not receiving antibiotics (relative risk, 0.22; 95% CI, 0.06-0.86). The NNT to prevent one patient having an implant failure is 25 (95%CI, 13-100), based on a patient implant failure rate of 6% in people not receiving antibiotics. The following outcomes were not statistically significantly linked with implant failure: prosthesis failure, postoperative infection and adverse events (eg, gastrointestinal effects, hypersensitivity). CONCLUSIONS: There is some evidence suggesting that 2 g of amoxicillin given orally 1 h preoperatively significantly reduces failures of dental implants placed in ordinary conditions. It remains unclear whether postoperative antibiotics are beneficial, and which is the most effective antibiotic. One dose of prophylactic antibiotics prior to dental implant placement might be recommended.