Assessment of Apical Extrusion during Root Canal Irrigation with the Novel GentleWave System in a Simulated Apical Environment.

INTRODUCTION: This study assessed apical extrusion during treatment with GentleWave (GW; Sonendo Inc, Laguna Hills, CA), a conventional open-ended 30-G needle (CN), or Endovac (EV; SybronEndo, Orange, CA) in root canals enlarged to different dimensions with and without apical constriction. METHODS: Sixteen mandibular molars were mounted in an in vitro apparatus. Roots were immersed in a pressure-regulated chamber containing distilled water with pressure kept at 5.88 ± 0.15 mm Hg to simulate periapical back pressure. Mesiobuccal (curved ≤30°) and distal (straight) canals were instrumented to the working length (WL) as follows: minimal instrumentation (MI, #15/.04), traditional instrumentation (#35/.06), or overinstrumentation (OI, #35/.06, to the WL + 1 mm). Canals were tested 5 times each with distilled water using GW, CN (at WL-3 mm), or EV and the mass (g) of extruded water recorded. Extrusion frequency and mean extruded mass were compared for each canal, irrigation group, and canal instrumentation mode (Wilcoxon t test, P < .05). RESULTS: No extrusion occurred with GW and EV, whereas the frequency of extrusion with CN was 33%. Mean extruded water mass using CN ranged in mesial canals from 0.000 ± 0.000 g (OI) to 0.047 ± 0.098 g (MI) and in distal canals from 0.123 ± 0.191 g (MI) to 0.505 ± 0.490 g (OI). With traditional instrumentation and OI instrumentation, extruded mass in distal canals was significantly higher than in mesial canals (P < .002) and distal canals with MI (P < .020). CONCLUSIONS: Within this study's limitations, root canal treatment with GW and irrigation with EV was not associated with extrusion. Extruded irrigation mass using the open-ended 30-G needle depended on the canal type and enlargement. These results have to be interpreted with caution, and further investigations are warranted to evaluate the possibility of extrusion using GW in different tooth types and clinical situations.

Clinical decision making for a tooth with apical periodontitis: the patients' preferred level of participation.

INTRODUCTION: To effectively engage patients in clinical decisions regarding the management of teeth with apical periodontitis (AP), there is a need to explore patients' perspectives on the decision-making process. This study surveyed patients for their preferred level of participation in making treatment decisions for a tooth with AP. METHODS: Data were collected through a mail-out survey of 800 University of Toronto Faculty of Dentistry patients, complemented by a convenience sample of 200 patients from 10 community practices. The Control Preferences Scale was used to evaluate the patients' preferences for active, collaborative, or passive participation in treatment decisions for a tooth with AP. Using bivariate and logistic regression analyses, the Gelberg-Andersen Behavioral Model for Vulnerable Populations was applied to the Control Preferences Scale questions to understand the influential factors (P ≤ .05). RESULTS: Among 434 of 1,000 respondents, 44%, 40%, and 16% preferred an active, collaborative, and passive participation, respectively. Logistic regression showed a significant association (P ≤ .025) between participants' higher education and preference for active participation compared with a collaborative role. Also, immigrant status was significantly associated with preference for passive participation (P = .025). CONCLUSIONS: The majority of patients valued an active or collaborative participation in deciding treatment for a tooth with AP. This pattern implied a preference for a patient-centered practice mode that emphasizes patient autonomy in decision making.

Five-year longitudinal assessment of the prognosis of apical microsurgery.

INTRODUCTION: Apical surgery is an important treatment option for teeth with post-treatment apical periodontitis. Knowledge of the long-term prognosis is necessary when weighing apical surgery against alternative treatments. This study assessed the 5-year outcome of apical surgery and its predictors in a cohort for which the 1-year outcome was previously reported. METHODS: Apical microsurgery procedures were uniformly performed using SuperEBA (Staident International, Staines, UK) or mineral trioxide aggregate (MTA) (ProRoot MTA; Dentsply Tulsa Dental Specialties, Tulsa, OK) root-end fillings or alternatively Retroplast capping (Retroplast Trading, Rorvig, Denmark). Subjects examined at 1 year (n = 191) were invited for the 5-year clinical and radiographic examination. Based on blinded, independent assessment by 3 calibrated examiners, the dichotomous outcome (healed or nonhealed) was determined and associated with patient-, tooth-, and treatment-related variables using logistic regression. RESULTS: At the 5-year follow-up, 9 of 191 teeth were unavailable, 12 of 191 teeth were extracted, and 170 of 191 teeth were examined (87.6% recall rate). A total of 129 of 170 teeth were healed (75.9%) compared with 83.8% at 1 year, and 85.3% were asymptomatic. Two significant outcome predictors were identified: the mesial-distal bone level at ≤ 3 mm versus >3 mm from the cementoenamel junction (78.2% vs 52.9% healed, respectively; odds ratio = 5.10; confidence interval, 1.67-16.21; P < .02) and root-end fillings with ProRoot MTA versus SuperEBA (86.4% vs. 67.3% healed, respectively; odds ratio = 7.65; confidence interval, 2.60-25.27; P < .004). CONCLUSIONS: This study suggested that the 5-year prognosis after apical microsurgery was 8% poorer than assessed at 1 year. It also suggested that the prognosis was significantly impacted by the interproximal bone levels at the treated tooth and by the type of root-end filling material used.

Characterization of an ex vivo model for the assessment of root canal disinfection.

Root canal bacteria in teeth with apical periodontitis were enumerated after extraction and incubation. Canals in 36 teeth were sampled after: S1, incubation for 2 hours (group A), 2 days (group B), 4 days (group C), and 6 days (group D); S2, subsequent incubation for 1 week; S3, canal disinfection; and S4, final incubation for 1 week. Bacterial concentrations were determined by culture (colony-forming unit [CFU]) and epifluorescence-microscopy (EFM) and compared by using pairwise and exact-permutation tests (p < 0.05). CFU counts were lower than EFM counts. CFU counts in S1 were higher in Gp(A) than in Gp(C) (p < 0.004) and Gp(D) (p < 0.02). EFM counts in S1 were higher in Gp(A) than in Gp(C) (p < 0.02). Both enumeration methods showed bacterial counts decreasing from S1 to S2 (p < 0.04). EFM was superior to culture in this ex vivo model. The indigenous flora survived incubation for 6 days, but the adverse effect of initial access would preclude testing of disinfection protocols that require two sessions.

Short-term cytotoxicity assessment of components of the epiphany resin-percha obturating system by indirect and direct contact millipore filter assays.

The Epiphany Resin-Percha Obturating System was assessed for cytotoxicity, compared with gutta-percha and AH-Plus sealer. Specimen disks (Resilon, gutta-percha), filled glass rings (sealers), or imbibed cellulose disks (primer, thinning resin) were placed over Millipore filters in direct or indirect contact with HeLa cell monolayer, incubated for 2 hours, and stained with tetrazolium blue. Cytotoxicity was rated by the surrounding unstained zone: none (0 mm), mild (12 mm). Data were analyzed with one-way ANOVA and post hoc pairwise t tests. Unstained zones indicating moderate cytotoxicity were significantly larger (p < 0.05) for Epiphany primer than for thinning resin and for freshly mixed AH-Plus than for Epiphany sealer. Set sealers (24 and 48 hours), gutta-percha, and Resilon elicited noncytotoxic responses. In conclusion, cytotoxicity of set Epiphany sealer and Resilon was comparable with that of set AH-Plus and gutta-percha. Cytotoxicity of freshly mixed Epiphany sealer, primer, and thinning resin did not exceed that of freshly mixed AH-Plus.