[Need for dentists with post-graduate training in endodontology according to members of the Swiss Dental Association].

This questionary-based study was financed by the Swiss Society for Endodontology (SSE). At the time of this survey (2022) there were merely 20 board-certified endodontists in Switzerland, and 239 other members of the SSE, i.e. general practitioners with some form of post-graduate endodontic training or a keen interest in the field. The aim of this investigation was to evaluate the need for a higher number of trained endodontists as viewed by the general population of dentists in Switzerland. An electronic questionary in either German, French, or Italian was sent to all 4072 active members of the Swiss Dental Association (SSO). The questionnaire focused on the background of the surveyed dentists, their willingness to refer endodontic cases to a specialist or colleague with a focus on endodontics, their propensity to do so, and their perceived need for endodontists in their region. The response rate was 21%, and was similar between the different regions and cantons. Seventy-nine (9%) of the dentists participating in the survey were members of the SSE, while 16 (2%) were board-certified. Merely 7% of the participants received endodontic referrals themselves, while 81% referred cases in some instances. However, only 13% of participants referred endodontic cases always or regularly. The main reason for not referring was the belief by the surveyed dentists that they could perform the endodontic treatments themselves. Long distance to the next endodontic specialist or expert was the second most frequently given reason not to refer cases. A total of 58% of the participants believed that there were enough endodontists in Switzerland to cover the encountered clinical problems.

The Impact of Changing from First- to Fifth-Generation Nickel-Titanium Rotaries on Root-Filling Quality in a Clinical Undergraduate Course

In this retrospective study, it was investigated whether the use of a fifth-generation rotary system (ProTaper Next) resulted in improved radiological root filling quality compared to a first-generation counterpart (ProFile) in a controlled student course setting. Cases treated by fourth-year dental students in the 2020/21 academic year were collected and compared to those treated in 2019/20. Root canals in the former group were all instrumented using the ProTaper Next system, and the latter using the ProFile system. All other clinical parameters were similar between the two academic years, including the time of pre-clinical teaching, hands-on course hours, endodontic auxiliaries, and chemicals used for treatment. After excluding patients who were not available or refused to give their informed consent to this study (n = 20), and excluding teeth with missing or poor radiographs (n = 16), the fillings in 178 roots could be assessed by two calibrated observers blinded to the system that was used. The primary outcome was the radiographic quality of the root fillings according to the five-scale modified MOLANDER score. The secondary outcome was the number of separated rotary instruments by group. Both instrumenting systems resulted in a similar number of "excellent" root fillings (score I), 59 % in the ProTaper Next group and 60% in the ProFile group, with no statistically significant difference in outcome scores between groups (Probability > ChiSquare = 0.70). Furthermore, there was merely one separated instrument in the ProTaper Next group, and none in the ProFile group (Fisher's exact test, p = 1.00).

What happened to our former students five to six years after graduation? An endodontic teacher's perspective.

Endodontic teaching follows common concepts in the four Swiss dental schools. The aim of this survey was to ask former Swiss dental students how they adopted these endodontic concepts in clinical practice. All the graduates of the years 2012 and 2013 (n = 196) were targeted in 2018 using an internet-based anonymous questionnaire, which was based on five initial questions. One hundred forty-one individuals (participants) filled in these questions on their work situation and referral concepts (72% response rate). Those 111 participants who performed root canal treatments themselves were the focus group. They answered an additional 11 questions. Their affinity towards performing endodontic treatments was investigated. The use of rubber dam isolation served as a surrogate to see if biological principles were respected. Furthermore, it was asked which instrumentation systems they used in daily practice, and how they perceived the impact of their superior/employer on these choices. Of the 141 survey participants 55 were men and 86 women. Thirty-eight of these (27%) reported to refer difficult endodontic cases. Individuals in the focus group had an overall positive attitude towards endodontics. There was very little variance in the responses between the four Swiss dental schools. The vast majority (86.5%) reported to use rubber dam routinely. More than half in the focus group used reciprocating systems, and only a few (22.5%) would still use the rotary system they were taught at university. There was a significantly (p < 0.05) higher perceived impact of the employer on choice of instrumenting system versus the use of rubber dam.

Treatment options for permanent teeth with deep caries.

The goal of this narrative review was to summarize and compare treatment options for permanent teeth carious lesions that are radiographically close to the pulp chamber. Thanks to adhesive restorative materials, minimally invasive approaches are possible. In this context, the old question arises as to whether caries must be excavated completely, i.e., down to hard dentin, or whether it could be advantageous to leave some soft dentin, or even merely seal the whole lesion. To answer this question, the microbiological aspects of the lesion must be considered, along with the immunological response in the dental pulp, with the concurrent possible negative outcomes for the patient. Both aspects are considered in this review, and clinical studies comparing different treatment modalities are discussed. Situations in which calcium silicate cements could be advantageous over the gold standard calcium hydroxide preparations for covering the dentin/pulp wound are also discussed.

Stabilizing sodium hypochlorite at high pH: effects on soft tissue and dentin.

INTRODUCTION: When sodium hypochlorite solutions react with tissue, their pH drops and tissue sorption decreases. We studied whether stabilizing a NaOCl solution at a high pH would increase its soft-tissue dissolution capacity and effects on the dentin matrix compared with a standard NaOCl solution of the same concentration and similar initial pH. METHODS: NaOCl solutions were prepared by mixing (1:1) a 10% stock solution with water (standard) or 2 mol/L NaOH (stabilized). Physiological saline and 1 mol/L NaOH served as the controls. Chlorine content and alkaline capacity of NaOCl solutions were determined. Standardized porcine palatal soft-tissue specimens and human root dentin bars were exposed to test and control solutions. Weight loss percentage was assessed in the soft-tissue dissolution assay. Three-point bending tests were performed on the root dentin bars to determine the modulus of elasticity and flexural strength. Values between groups were compared using one-way analysis of variance with the Bonferroni correction for multiple testing (α < .05). RESULTS: Both solutions contained 5% NaOCl. One milliliter of the standard and the stabilized solution consumed 4.0 mL and 13.7 mL of a 0.1-mol/L HCl solution before they reached a pH level of 7.5, respectively. The stabilized NaOCl dissolved significantly more soft tissue than the standard solution, and the pH remained high. It also caused a higher loss in elastic modulus and flexure strength (P < .05) than the control solutions, whereas the standard solution did not. CONCLUSIONS: NaOH-stabilized NaOCl solutions have a higher alkaline capacity and are thus more proteolytic than standard counterparts.

Comparative assessment of time-related bioactive glass and calcium hydroxide effects on mechanical properties of human root dentin.

Suspensions of micro- or nanoparticulate SiO(2)-Na(2)O-CaO-P(2)O(5) bioactive glasses could potentially be used as dressings in traumatized front teeth with open apices as an alternative to Ca(OH)(2). These materials have a disinfecting capacity similar to Ca(OH)(2), but bear the advantage of bioactivity. However, because bioactive glasses initially act as alkaline biocides just as Ca(OH)(2) does, they may also negatively affect mechanical dentin properties over time. This was assessed in the current study using standardized human root dentin bars. Specimens were immersed in 1:20 (wt vol(-1)) suspensions of nanometric bioactive glass 45S5 or calcium hydroxide for 1, 10, or 30 days. Control specimens were immersed in pure saline for 30 days (n = 20 per group). Subsequently, modulus of elasticity (E) and flexural strength (FS) of the specimens were determined. Results were compared between groups using one-way anova and Scheffé's post-hoc test. Ca(OH)(2) caused a significant (P < 0.001) 35% drop in mean flexural strength values compared to the control treatment after 10 days. No further change was observed between 10 days and 30 days. Bioactive glass caused a 20% drop in mean flexural strength as compared to the control after 10 days. However, this difference did not reach statistical significance (P > 0.05). No effects of either material on dentin modulus of elasticity values were observed. It was concluded that the calcium hydroxide suspension affected the dentin more than the bioactive glass counterpart; however, the effect was self-limiting and probably restricted to superficial dentin layers, as suggested by the mere decrease in flexural strength but not in modulus of elasticity values.

Impact of irrigant sequence on mechanical properties of human root dentin.

To get the root canal system free of organic debris and the smear layer, it has been recommended to irrigate with a NaOCl solution during instrumentation, followed by a rinse with a chelating agent such as ethylenediaminetetraacetic acid (EDTA) and a final irrigation with NaOCl. However, both hypochlorite and EDTA weaken dentin through dissolution of its organic and inorganic components, respectively. EDTA exposes the organic dentin matrix, which could then be attacked more easily by hypochlorite. It was the aim of this study to assess the impact of different irrigation sequences of NaOCl (2.5% w/v; total exposure time, 24 minutes) and EDTA (17%; 3 minutes) on the elastic modulus and flexure strength of standardized human root dentin bars (n = 11 per group). Exposures to solely EDTA (3 minutes), NaOCl (24 minutes), and water were used as control treatments. Specimens were subjected to 3-point bending tests; modulus of elasticity and flexure strength values were compared between groups with one-way analysis of variance followed by Fisher probable least-squares difference test. The alpha-type error was set at .05. The 24-minute exposure to the hypochlorite solution caused a significant drop in flexure strength compared with water- or EDTA-treated controls (P < .05), whereas the elastic modulus remained unaffected. In contrast, the short exposure to EDTA as is clinically recommended did not affect the mechanical dentin parameters under investigation, regardless of the irrigant sequence that was used.

Factors affecting the outcome of orthograde root canal therapy in a general dentistry hospital practice.

OBJECTIVE: The goal of this study was to weigh the impact of patient-related, tooth-related, and treatment-related factors on therapy outcome in a series of consecutive patients. STUDY DESIGN: Eighty-four patients were included. Of these, 66 (79%) were available for recall after > or = 30 months (mean = 46 months). Root canal treatments were performed using a standard protocol. At recall, teeth were scored by means of the periapical index (PAI), which was the dependent variable (dichotomized to sound/ unsound). Explanatory variables were patient age, integrity of the nonspecific immune system, smoking status, dichotomized PAI score before treatment, initial treatment versus retreatment, prior exposition of the root canal to saliva, stainless-steel hand versus NiTi rotary instrumentation, and quality of root filling. Unit of observation was the patient-individual. Data were analyzed using univariate tests and backward stepwise logistic regression analysis. RESULTS: After 5 steps with elimination of the least significant independent variable, status of the immune system (P = .05), initial PAI (P = .04), and root filling quality (P = .01) were found to be the indispensable predictors for treatment outcome. Using these 3 explanatory variables, the logistic regression model had a predictive value of 87%, compared to 91% with all 8 variables. Success rate at recall (PAI < or = 2 without symptoms) was 88% (95% CI = 78, 94). CONCLUSION: The integrity of a patient's nonspecific immune system, which has been neglected in earlier investigations, is a significant predictor for endodontic treatment outcome, and should receive more attention in future studies.