Activity of Two Antimicrobial Peptides against Enterococcus faecalis in a Model of Biofilm-Mediated Endodontic Infection.

Enterococcus faecalis is a common cause of biofilm-associated opportunistic infections, which are often difficult to treat. The formation of E. faecalis biofilms on the dentinal walls of the root canal is frequently the cause of endodontic treatment failure and secondary apical periodontitis. In a preliminary work, two recognized antifungal peptides, KP and L18R, showed antibacterial activity against planktonic E. faecalis cells at micromolar concentrations. Moreover, L18R proved to reduce the biomass in the early stage of E. faecalis biofilm development on polystyrene plates, while a qualitative biofilm inhibition was demonstrated on hydroxyapatite disks by confocal laser scanning microscopy (CLSM). The aim of this study was to better characterize the effect of both peptides on E. faecalis biofilm. A reduction in metabolic activity after peptide treatment was detected by Alamar Blue assay, while a remarkable impairment in the architecture of E. faecalis biofilms on hydroxyapatite disks, along with a significant reduction in viable bacteria, was caused mostly by L18R, as assessed by CLSM and scanning electron microscopy. The lack of cytotoxicity of the investigated peptides against L929 murine fibroblasts was also determined. Obtained results suggest L18R as a promising candidate for the development of new strategies for endodontic infection control.

Computer-guided implant placement in contact with root remnants in the esthetic area.

The extraction of a tooth with root resorption can be a complicated procedure and can result in the removal of a significant amount of alveolar bone. In the anterior maxilla, esthetic rehabilitation of damaged sites with implant-supported crown could require multiple surgeries. Patients often ask for an alternative, and minimally invasive treatments are generally preferred. In this paper, a clinical case of implant-supported crown in a site affected by root resorption is described. Immediate implant was placed leaving some root fragments in the osteotomy site, thus avoiding invasive extractive surgeries. A minimally invasive flapless technique with a computer-guided implant placement procedure was used. After ?8 years, clinical and radiologic data were stable, gingival tissues around the implant appeared healthy, no dark translucency appeared through marginal gingiva around the implant, and there was no pathologic probing pocket depth ?or bleeding on probing. In the presence of root resorption and ankylosis, computer-guided surgery could be helpful to prepare a precise implant site through various tissues, such as partially resorbed root remnants. (Quintessence Int 2021;52:132-137; doi: 10.3290/j.qi.a45432).

Comparative Results of Single Implants With and Without Laser-Microgrooved Collar Placed and Loaded with Different Protocols: A Long-Term (7 to 10 years) Retrospective Multicenter Study.

PURPOSE: This nonrandomized, retrospective multicenter study aimed to evaluate success rates, peri-implant marginal bone loss, and clinical parameters around single implants with and without laser-microgrooved collars placed and loaded using different protocols after 7 to 10 years of function. MATERIALS AND METHODS: A chart review was used to select patients treated at five private dental clinics with single dental implants with and without laser-microgrooved collars. Cumulative success rates, peri-implant marginal bone loss, probing depth, Plaque Index, bleeding on probing, and gingival recession were recorded at baseline examinations (ie, definitive restoration delivery) and at each year during the follow-up period. RESULTS: Three hundred single implants (140 without laser-microgrooved collars and 160 with 1.7-mm laser-microgrooved collars) in 300 patients were selected. At the completion of the study period, 26 patients and 26 implants (17 with and 9 without a laser-microgrooved collar) were classified as "dropouts." Implants and restorations were categorized into two subgroups each for a total of four study groups: group 1, immediate implant placement; group 2, delayed implant placement; group 3, immediate nonocclusal loading of prostheses; and group 4, delayed loading of prostheses. Nineteen implants (6.9%) failed clinically (4 [2.7%] with and 15 [11.4%] without a laser-microgrooved collar). The difference in cumulative success rates was statistically significant (P < .05). Radiographically, at the end of the follow-up period, the laser-microgrooved group showed a mean peri-implant marginal bone loss of 0.64 mm compared with 1.82 mm for the non-laser-microgrooved group. At the same time point, a mean probing depth of 0.76 mm was observed for the laser-microgrooved group compared with 2.75 mm for the non-laser-microgrooved group. A statistically significant difference in peri-implant marginal bone loss and probing depth between the two types of implant collars was evident (P < .05). No statistically significant correlation was noted between the types of implant placement/prosthetic restoration and clinical parameters. CONCLUSION: Implants with a laser-microgrooved collar appear to influence the peri-implant soft and hard tissue stability, reducing the probing depth levels and the peri-implant marginal bone loss by more than 50% after 10 years of function, regardless of the type of implant placement and loading protocol.

A Retrospective Multicenter Study on Short Implants With a Laser-Microgrooved Collar (≤7.5 mm) in Posterior Edentulous Areas: Radiographic and Clinical Results up to 3 to 5 Years.

PURPOSE: We aimed to retrospectively evaluate the radiographic and clinical results and the success rate of short implants with a laser-microgrooved collar (≤7.5 mm) placed in the posterior areas after up to 3 to 5 years of function and the possible influence of several variables-such as gender, periodontitis, smoking habit, location, implant stability at placement, and prosthetic fixation design-on implant marginal bone loss (MBL). MATERIALS AND METHODS: A chart review was used for this multicenter study, which involved 5 private dental clinics. All patients had been treated with short dental implants with a laser-microgrooved collar from January 2012 to December 2015. RESULTS: A total of 174 patients (99 male and 75 female patients; mean age, 51.6 ± 2.8 years) with 254 implants were evaluated. Seven short implants failed. The cumulative success rate was 97.2%, without a statistically significant difference between implants placed in the posterior maxilla and mandible. The mean MBL was 0.18 ± 0.7 mm at the mesial aspect and 0.19 ± 0.6 mm at the distal aspect. No statistical relationships were found between MBL and gender, periodontitis, smoking habit, location, implant stability at placement, and prosthetic fixation design. CONCLUSIONS: At the end of the 3- to 5-year follow-up period, short implants with a laser-microgrooved collar (≤7.5 mm) in the posterior areas yielded a relatively high cumulative success rate. The laser-microgrooved collar implant maintained stable marginal bone levels. No investigated variable was statistically associated with MBL.

Prevalence of Candida Species in Endodontic Infections: Systematic Review and Meta-analysis.

INTRODUCTION: Candida in endodontic infections has been investigated in a large number of studies, but its role as an endodontic pathogen is still debatable. The aim of this study was to systematically review the literature on the prevalence of Candida species in root canal infections. METHODS: Extensive literature research was performed in the most important electronic biomedical databases, and additional studies have been identified from references from relevant articles. Studies were critically appraised using a modified version of the Joanna Briggs Institute Critical Appraisal Checklist. RESULTS: From 2225 unique records, 2118 were excluded on the basis of title and abstract. Of the remaining 107 studies, 50 were excluded after full-text review, and 57 were included for qualitative and quantitative analysis. The overall prevalence of Candida spp. in root canal infections was 8.20% (95% confidence interval, 5.56%-11.21%). Candida albicans was the most frequently isolated species. Significant heterogeneity among studies was observed (P < .001, I2 = 86.07%). Subgroup analyses revealed a higher prevalence of Candida spp. from African samples. All studies considered, a high or unclear risk of bias was prevalent regarding 6 out of the 8 items considered in the critical appraisal. CONCLUSIONS: Candida spp. occurred in a small proportion of root canal infections. Further and better designed research is needed to investigate the real contribution of Candida spp. to the microbial ecology in infected root canals.

Adhesive post-endodontic restorations with fiber posts: push-out tests and SEM observations.

OBJECTIVES: Nowadays, the restoration of endodontically treated teeth is based on the use of materials with a modulus of elasticity similar to that of dentin (18.6 GPa). Fiber posts, resin cements and some composite resins all have this characteristic. This study evaluated the bond strength between luting materials, root dentin and fiber posts through push-out tests and examined the integration among these three components through scanning electron microscopy. METHODS: Endodontically treated extracted teeth and plastic plates were used to test the interface between luting agent and dentin and luting agent and post. RESULTS: Chemical affinity between different components (luting materials and fiber posts) is extremely important in achieving high bond strength. The bond strength tests and SEM observations showed that in vitro, composite resins perform better than resin cements. SIGNIFICANCE: The in vivo use of these materials may significantly reinforce residual tooth structure therefore reducing the risk for fracture and debonding.