Objectives To assess the association between periodontal disease and Helicobacter pylori (H. pylori) infection in oral cavity. Materials and methods We searched PubMed, Embase, Web of Science, Cochrane library, Gray literature, and clinicaltrials.gov for eligible studies up to September 25, 2019. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. The random-effects model was used with the software STATA 13.0.  https://www.selleckchem.com/products/AZD6244.html  The Newcastle-Ottawa-Scale was used for quality evaluation. Results Twelve observational studies (eight from Asia, one from Europe, and three from the South America) involving 2727 participants were included in the meta-analysis. The overall pooled results showed that H. pylori infection in oral cavity was associated with periodontal disease (OR 2.53, 95% CI 1.86-3.44, P less then 0.05). No significant heterogeneity among the articles was observed (I2 = 44.3%, P less then 0.05). The sensitivity analysis indicated that the result of our meta-analysis was generally stable. The Begg test and the Egger test both showed no publication bias was observed (P = 0.45 and P = 0.18 respectively). Conclusions Based on current available evidence, it seemed there was a correlation between oral H. pylori infection and the occurrence of periodontal disease. However, since most of the data comes from Asia, more large-scale investigations with high quality from all over the world are needed to confirm the association. Clinical relevance H. pylori infection in oral may have a positive association with the prevalence of periodontal disease mainly in Asian populations.Objectives To evaluate ex vivo the efficacy of the integrated motor Tri Auto ZX2 in controlling the apical extent of preparation compared to conventional visual control (CVC) of the working length (WL). Materials and methods Eighty standardized mandibular premolars were divided into five groups (n = 16). In the CVC group, instruments were used in continuous rotation (CR) and visual control performed by means of rubber stoppers. For each of the remaining groups, it was assigned a combination of a motion (CR or optimal torque reverse (OTR)), and an apical function (Auto Apical Reverse (AAR) or Optimum Apical Stop (OAS)). Root canals were prepared using the apical functions at 0.5 mark using an alginate model. Difference between the final WL and the actual length post-instrumentation was calculated. Data were analyzed statistically with the significance set at 5% (ANOVA, Tukey HSD). Results There was no difference in the mean WL among the groups, except between the CR combined to OAS compared to CVC (P > 0.05). Although CVC resulted in two cases beyond the foramen, no significant difference was found among the groups when comparing the distributions of measurements (P > 0.05). Conclusions All combinations of motion and apical control functions of Tri Auto ZX2 provided an adequate apical limit ex vivo, similar to the visual control using rubber stoppers. Clinical relevance TriAuto ZX2 was efficient to control the apical extent of preparation dispensing the need for calibrating the files, regardless of the different settings. This motor might potentially prevent over-instrumentation by continuously monitoring the apical limit.Objectives The present study aimed to investigate the changes in the enamel bond strengths of universal adhesives in the early phase of specimen creation and evaluate the effect of double-layer application on enamel bond effectiveness using different etching modes. Method Four universal adhesives, namely Clearfil Universal Bond Quick, G-Premio Bond, Scotchbond Universal, and Tokuyama Universal Bond, were used. Clearfil SE Bond two-step self-etch adhesive system was used as a comparison. Fifteen specimens per group were used for determining the shear bond strength (SBS) to bovine enamel in the etch-and-rinse or self-etch mode. The adhesive was applied to specimens in accordance with the manufacturers' instructions (single-layer application), or the adhesive was applied twice (double-layer application). The bonded specimens were stored in distilled water at 37 °C for 5 min or 1, 6, 12, or 24 h before SBS testing. The flexural properties of the resin composite Clearfil AP-X were measured for the same storage periods. Results All universal adhesives exhibited increased SBS values with prolonged storage periods regardless of the application technique or etching mode used. Double-layer application was associated with higher SBS values than single-layer application for most universal adhesives over the same storage period. Conclusion Phosphoric acid pre-etching and double-layer application of universal adhesives resulted in increased enamel bond strength in the early phase of specimen bonding. Clinical relevance Care should be taken when using universal adhesives in the self-etch mode for enamel bonding because the enamel adhesion is sensitive to the duration after filling.Objectives Whereas the key role of subgingival instrumentation in periodontal therapy is well known, the influence of operators' experience/training with different devices on treatment results is yet uncertain. Therefore, we assessed untrained undergraduate students, working on manikins, as to how effectively they learn to use curettes (GRA) and sonic scalers (AIR); hypothesizing that AIR will result in higher relative cleaning efficacy (RCE) than GRA. Material and methods Before baseline evaluation (T0), 30 operators (9 males, 21 females) received a 2-h theoretical lesson for both instruments, followed by a 12-week period with a weekly digitized training program for 45 min. During three sessions (T1-T3), the operators had to instrument six equivalent test teeth with GRA and AIR. At T0-T3, treatment time, proportion of removed simulated biofilm (RCE-b), and hard deposits (RCE-d) were measured. Results At T0, RCE-b was in mean(SD) 64.18(25.74) % for GRA, 62.25(26.69) % for AIR; (p = 0.172) and RCE-d 85.48(12.32) %/ 65.71(15.27) % (p less then 0.001). At T3, operators reached highest RCE-b in both groups (GRA/AIR 71.54(23.90) %/71.75(23.05)%; p = 0.864); RCE-d GRA/AIR 84.68(16.84) %/77.85(13.98) %; p less then 0.001). Both groups achieved shorter treatment times after training. At T3, using curettes was faster (GRA/AIR 16.67(3.31) min/19.80(4.52) min; p less then 0.001). Conclusions After systematic digitized training, untrained operators were able to clean 70% of the root surfaces with curettes and sonic scalers. Clinical relevance It can be concluded that a systematic digitized and interactive training program in manikin heads is helpful in the training of root surface debridement.