Analysis of operator variability in standardized root canal preparation with Ni–Ti instruments

Summary Objectives The aim of this study is to assess the influence of the operator variability during the preparation of standard resin blocks and the learning process with Ni–Ti instruments, the null hypothesis being that there are no significant differences regarding dentin removal, variation of the angle and radius of curvature, centering of the preparation, and time required by operator with different clinical experience. Materials and methods 100 standard resin blocks were used for this study. The blocks were divided into 4 groups of 25, and each group was assigned to a different operator. Operators 1 and 2 were 4th year DDS undergraduate students that had never performed endodontic treatments and as such could be considered as inexperienced operators. Operators 3 and 4 were 2 clinicians with 10 years experience and that were familiar with endodontic treatments and instrumentation (experienced operators). Many parameters were measured and compared. Result Differences could be detected between the 2 different level of clinical experience. Conclusions Under the experimental conditions of this study, experience of the operators can be considered as a crucial factor when all the other parameters are kept standard. In conclusion the null-hypothesis has to be rejected. Statistically significant differences exist in dentin removal, in the variation of the degree of curvature, in the centering of the preparation and in the time needed for the preparation when operators with different clinical experience where tested

Dental Caries Occurrence in Inflammatory Bowel Disease Patients: A Systematic Review and Meta-Analysis

Objective: The present review aimed to systematically evaluate the occurrence of caries in patients with inflammatory bowel disease (IBD), either Crohn's disease (CD) or ulcerative colitis (UC), compared to healthy controls. Materials and Methods: MEDLINE (PubMed), Embase, Google Scholar, LILACS, and Cochrane Library electronic databases were screened. Caries experience was measured through the Decayed, Missing, Filled Teeth (DMFT) index. The weighted mean difference (WMD) with 95% confidence interval was calculated between IBD patients and healthy controls. Results: Six studies were selected for the inclusion in the systematic review, 5 of which were also included in the quantitative synthesis of data. The WMD in the DMFT index between IBD and healthy subjects was 3.04 (1.52, 4.56) (p = 0.10). Subgroup analysis showed no difference (p = 0.31) between CD (2.52 [0.54, 4.49]) and UC (4.01 [1.52, 4.56]) subjects. Conclusions: There is a remarkably higher past and present occurrence of dental caries in subjects with IBD than healthy controls. This result should encourage clinicians to include oral health preventive programs in the overall treatment plan of IBD patients

Healthy lifestyles are associated with a better response to periodontal therapy: A prospective cohort study

Aim: To evaluate the association between lifestyle behaviours and clinical periodontal outcomes following Steps 1/2 of periodontal therapy.Methods: A total of 120 subjects with untreated Stage II/III periodontitis participated in this study. At baseline, questionnaires were administered to assess the following lifestyle behaviours: adherence to Mediterranean diet (MD), physical activity (PA) and stress levels, sleep quality, smoking and alcohol use. Participants received Steps 1/2 of periodontal therapy and were re-evaluated after 3 months. A composite outcome of the endpoint of therapy (i.e., no sites with probing pocket depth [PPD] >= 4 mm with bleeding on probing, and no sites with PPD >= 6 mm) was regarded as the primary outcome. Simple and multiple regression analyses were used to evaluate the association between lifestyle behaviours and clinical periodontal outcomes. Disease severity at baseline, body mass index, diabetes, household disposable income and plaque control were considered as confounders.Results: Multiple regression analyses showed significantly lower odds of achieving the endpoint of therapy in subjects with poor sleep quality (odds ratio [OR] = 0.13; 95% confidence interval [CI]: 0.03-0.47; p <.01), smoking (OR = 0.18; 95% CI: 0.06-0.52; p <.05) and alcohol use above the suggested intake (OR = 0.21; 95% CI: 0.07-0.63; p <.01). Subjects with a combination of `unhealthy lifestyles' (low adherence to MD and low PA levels and high levels of stress and poor sleep quality) showed higher proportions of residual PPD >= 6 mm (MD = 1.51; 95% CI: 0.23-2.80; p <.05) and lower odds of achieving the endpoint of therapy (OR = 0.85; 95% CI: 0.33-0.99; p <.05) at re-evaluation.Conclusions: Subjects with unhealthy lifestyle behaviours showed worse clinical outcomes 3 months after Steps 1/2 of periodontal therapy

The presence of Enterococcus faecalis in saliva as a risk factor for endodontic infection

Aim: The aim of the present study was to investigate and correlate the prevalence of Enterococcus faecalis in saliva and in root canals with different pulpal and periapical conditions. Methodology: Sixty-seven patients were divided into five groups based on pulpal and periapical tissue status: healthy vital teeth (HVT, n=7), healthy treated teeth without lesion (HTT, n=9), irreversible pulpitis (IP, n=13), necrosis (N, n=18), and post-treatment apical periodontitis (PTAP, n=20). Saliva, rubber dam, sterility control and pre-treatment root canal samples were collected and microbiologically processed by culture method. The phylogenetic relationship of E. faecalis isolates collected from root canals and saliva were investigated by whole genome sequencing. Fisher's exact test was used to correlate the presence of E. faecalis in root canals or saliva with clinical and/or radiographic findings. Linear/logistic regression analyses were performed to establish the relationship between the presence of E. faecalis in root canals, saliva, and the status of periapical tissues. Results: E. faecalis was found in 18 root canal and saliva samples. E. faecalis root canal isolates were recovered with the highest frequency from post-treatment apical periodontitis. The occurrence of E. faecalis in saliva was strongly associated with its detection in the root canals (P < 0.001). The pretreatment presence of E. faecalis in root canals was associated with significantly higher odds of having periapical lesions (OR=11.03; 95% CI, 1.27-95.70; p < 0.05). Saliva and root canal isolates from the same patient were highly correlated at the phylogenetic level (Jaccard index >0.95). Conclusion: This pilot study confirms the role of E. faecalis in developing peri-radicular lesions in secondary endodontic infections and suggests that saliva could be the main source of infection. Further studies are needed to investigate the exact origin of this bacteria and its true role in the pathogenesis of secondary/persistent endodontic infections

The Effect of Adding Different Antibiotics on the Resistance against Bacterial Leakage of AH 26 Sealer

Aim: Most endodontic sealers show antimicrobial activity before setting, but most of them also lose this ability after setting. Addition of an antibiotic may affect the properties of sealers such as sealing ability, setting time, and so on. The aim of this study was to assess whether the addition of antibiotics (amoxicillin, doxycycline, and clindamycin) improves the sealing ability of AH 26 sealer. Materials and Methods: Seventy extracted human mandibular premolars were used. After cleaning and shaping the canals, the teeth were divided into six groups: group 1: gutta-percha and AH 26 sealer, group 2: gutta-percha and AH 26 sealer+doxycycline, group 3: gutta-percha and AH 26 sealer+amoxicillin, group 4: gutta-percha and AH 26 sealer+clindamycin, group 5: gutta-percha without sealer (positive control), and group 6: gutta-percha and AH 26 sealer (the root surfacewere covered with nail varnish) (negative control). A microbial leakage model was used to assess the sealing ability. Results: Group 2 had the greatest resistance against bacterial leakage. Furthermore, combining AH 26 sealer with amoxicillin and clindamycin increased mean leakage time compared to AH 26 sealer solely. However, the differences between groups 1 and 3 as well as between groups 1 and 4 were not statistically significant. Conclusion: Incorporating antibiotics especially doxycycline into AH 26 sealer increases its resistance against bacterial leakage

Antimicrobial peptides active in in vitro models of endodontic bacterial infections modulate inflammation in human cardiac fibroblasts

Endodontic and periodontal disease are conditions of infectious origin that can lead to tooth loss or develop into systemic hyperinflammation, which may be associated with a wide variety of diseases, including cardiovascular. Endodontic and periodontal treatment often relies on antibiotics. Since new antimicrobial resistances are a major threat, the use of standard antibiotics is not recommended when the infection is only local. Antimicrobial peptides were recently demonstrated to be valid alternatives for dental treatments. The antimicrobial peptide M33D is a tetrabranched peptide active against Gram-negative and Gram-positive bacteria. It has a long life, unusual for peptides, because its branched form provides resistance to proteases. Here the efficacy of M33D and of its analog M33i/l as antibiotics for local use in dentistry was evaluated. M33D and M33i/l were active against reference strains and multidrug-resistant clinical isolates of Gram-negative and Gram-positive species. Their minimum inhibitory concentration against different strains of dental interest was between 0.4 and 6.0 mu M. Both peptides acted rapidly on bacteria, impairing membrane function. They also disrupted biofilm effectively. Disinfection of the root canal is crucial for endodontic treatments. M33D and M33i/l reduced E. faecalis colonies to one-twentieth in a dentin slices model reproducing root canal irrigation. They both captured and neutralized lipopolysaccharide (LPS), a bacterial toxin responsible for inflammation. The release of IL-1 beta and TNF alpha by LPS-stimulated murine macrophages was reduced by both peptides. Human cardiac fibroblasts respond to different insults with the release of proinflammatory cytokines, and consequently, they are considered directly involved in atherogenic cardiovascular processes, including those triggered by infections. The presence of M33D and M33i/l at MIC concentration reduced IL6 release from LPS- stimulated human cardiac fibroblasts, hence proving to be promising in preventing bacteria-induced atherogenesis. The two peptides showed low toxicity to mammalian cells, with an EC50 one order of magnitude higher than the average MIC and low hemolytic activity. The development of antimicrobial peptides for dental irrigations and medication is a very promising new field of research that will provide tools to fight dental infections and their severe consequences, while at the same time protecting standard antibiotics from new outbreaks of antimicrobial resistance. © 2022 by the authors