What is new in the 2023 European Society of Endodontology S3-level clinical practice guidelines?

BACKGROUND: The European Society of Endodontology published in 2023, the S3-level clinical practice guidelines, which supersede the Quality Guidelines for Endodontic Treatment published in 2006. OBJECTIVES: This review aims to summarize and compare the above guidelines to support their dissemination. METHOD: A narrative synthesis of the main differences alongside tabulation according to the main themes. RESULTS: Three tables were prepared according to the following themes: diagnosis of pulpal and apical condition; treatment of pulpitis; and treatment of nonvital pulp and apical periodontitis. CONCLUSIONS: A compared and simplified message regarding the most recent clinical practice guidelines has been prepared. REGISTRATION: Not applicable as a narrative review.

Assessing the impact of obturation techniques, kinematics and irrigation protocols on apical debris extrusion and time required in endodontic retreatment.

The aim of the study was to evaluate the impact of kinematics and irrigation protocols on the extrusion of apical debris during removal of different obturation techniques. A total of 144 single-rooted teeth were instrumented and obturated with Thermafil+AH Plus, Thermafil+AH Plus Bioceramic and single gutta-percha cone+AH Plus Bioceramic. Samples were divided according to the retreatment kinematics: continuous rotation or Jeni motion. Each sub-group was subjected to conventional irrigation or irrigation activated by EDDY. Extruded debris was collected in Eppendorf tubes, weighted and retreatment time was digitally recorded. Data were analysed with two-way ANOVA (p < 0.05). Debris extrusion was not significantly different between all groups. EDDY activation system and CanalPro Jeni required significantly longer time compared with other groups to remove Thermafil+AH Plus and single cone+AH Plus Bioceramic. Within current limitations, obturation technique, irrigation protocol and kinematics tested had no influence on apical extrusion debris, while they significantly impacted the retreatment time.

Effectiveness of root canal filling materials and techniques for treatment of apical periodontitis: A systematic review.

BACKGROUND: Apical periodontitis (AP) is an inflammatory disease of the apical periodontium as sequelae of pulp death. It is managed by disinfection and filling of the root canal space. OBJECTIVES: The aim of this systematic review was to investigate whether obturation techniques and materials used for root canal filling led to the management of AP. METHODS: A systematic review protocol was written following the preferred reporting items for systematic reviews and meta-analyses (PRISMA) checklist and registered on the international prospective register of systematic reviews (PROSPERO; CRD42021260275) including two populations, interventions, comparisons, outcomes and time (PICOT) for the research questions querying the effectiveness of obturation techniques (PICOT 1) and materials (PICOT 2) for the management of AP. Electronic searches were conducted on PubMed, ScienceDirect, Scopus and Embase search engines. Searches on International Endodontic Journal, Journal of Endodontics, Clinical Oral Investigations, Journal of Dental Research and Journal of Dentistry websites were also conducted, until May 2021. Both primary (tooth survival) and secondary outcomes were evaluated. The risk of bias was assessed by Cochrane RoB2 for the randomized and ROBINS-I for the nonrandomized trials. RESULTS: The search strategy identified 1652 studies, with 1600 excluded on the title and abstract screening, leaving 52 studies for full-text screening. In total, 10 studies met the inclusion criteria. The obturation technique and materials used did not affect the outcome of AP. Vertical compaction resulted in faster resolution of periapical lesions. The oral health-related quality of life of patients treated with lateral condensation exhibited poorer outcomes compared with single matched cone after 6 months of recall. DISCUSSION: The inclusion and exclusion criteria used for this systematic review enabled the capture of all the literature available on the effect of obturation techniques and materials on the outcome of AP. The data were heterogenous, and a number of articles investigating obturation techniques had no information on the materials and techniques used as they looked at the quality of fill. CONCLUSIONS: Included studies did not find any difference between different procedures (PICOT 1) and materials (PICOT 2). The risk of bias was high, thus the findings should be interpreted with caution. REGISTRATION: PROSPERO registration number: CRD42021260275.

Evaluation of the root filling quality with experimental carrier-based obturators: a CLSM and FEG-SEM analysis.

This study evaluated tubule penetration of GuttaFlow Bioseal with cold single cone or carrier-based technique, under confocal laser scanning microscopy (CLSM). Twenty straight single-rooted teeth were instrumented with Hyflex CM and divided in two groups (n = 10) according to the obturation method: single cold gutta-percha cones; experimental carrier-based obturators. GuttaFlow Bioseal, labelled with Rhodamine B dye, was used as sealer in both groups. Teeth transversally sectioned were observed under CLSM. Percentage of sealer penetration and integrity of sealer layer perimeter were measured. Surface and microstructural characteristics of obturators and gutta-percha cones were compared by FEG-SEM and EDX analysis. No significant differences were found between groups for each examined parameter. Significant differences (P < 0.05) were reported mainly within groups. Integrity was similar among and within groups. FEG-SEM/EDX analysis of obturators revealed the presence of Ba and Zn. Carrier-based obturation technique associated with GuttaFlow Bioseal does not seem to affect sealer penetration into dentinal tubules.

Efficacy of four local anaesthesia protocols for mandibular first molars with symptomatic irreversible pulpitis: A randomized clinical trial.

AIM: To examine the efficacy rate of four anaesthetic protocols in mandibular first molars with symptomatic irreversible pulpitis (SIP). METHODOLOGY: One hundred and sixty patients with a diagnosis of SIP were included in this randomized clinical trial. Patients were randomly allocated into four treatment groups (N = 40) according to the administered technique: Group 1 (IANB): standard inferior alveolar nerve block (IANB) injection; Group 2 (IANB + IO): standard IANB followed by a supplemental intraosseous infusion (IO) injection; Group 3 (IANB + PDL): standard IANB followed by a supplemental periodontal ligament (PDL) injection; Group 4 (IANB + BI): standard IANB followed by a supplemental buccal infiltration. Patients rated pain intensity using a verbal rating scale when the root canal treatment procedure was initiated, that is, during caries removal, access preparation and pulpectomy. Heart rate changes were recorded before, during and after each injection. The anaesthetic efficacy rates were analysed using chi-square tests, age differences using one-way anova, gender differences using Fischer Exact tests whilst heart rate changes were analysed using Kruskal-Wallis tests. Statistical significances were set at p < .05 level. RESULTS: All the included patients were analysed. No differences in the efficacy rate were found in relation to the age or gender of the participants amongst the study groups (p > .05). IANB + IO injections had a significantly higher efficacy rate (92.5%) when compared to other techniques (p < .05), followed by IANB + PDL injections (72.5%), IANB + BI injections (65.0%), with no significant differences between the IANB + PDL or IANB + BI injections (p > .05). IANB injection alone had a significantly lower rate (40%) compared to the other techniques (p < .05). A transient but significant rise in the heart rate was recorded in 60% (24/40) of patients who received the IANB + IO injection compared to other groups (p < .05). CONCLUSIONS: Inferior alveolar nerve block injection alone did not reliably permit pain-free treatment for mandibular molars with SIP. The use of an additional IO supplemental injection provided the most effective anaesthesia for patients requiring emergency root canal treatment for SIP in mandibular posterior teeth.

Retreatment of Experimental Carrier-Based Obturators with the Remover NiTi Instrument: Evaluation of Apical Extrusion and Effects of New Kinematics.

The objective of this study is to evaluate the retreatment time and weight of apically extruded debris yielded by two different kinematics during the removal of different root canal filling materials. Forty straight single-rooted extracted teeth were instrumented with HyFlex CM files and obturated with two different techniques: 25.04 HyFlex experimental carrier-based obturators (Coltène/Whaledent, Altstätten, Switzerland) (group 1) or 25.04 single gutta-percha cones (Roeko Coltène/Whaledent, Altstätten, Switzerland) (group 2) and Guttaflow Bioseal as the sealer. Samples were divided into four subgroups (n = 10) according to the used kinematics for the removal of root canal filling materials: continuous rotation (A) or retreatment motion (B) with a Remover and HyFlex EDM Nickel-Titanium instruments activated with a CanalPro Jeni micromotor (Coltène/Whaledent, Altstätten, Switzerland). Time for retreatment was digitally recorded, and debris extruded from the apex was collected in Eppendorf tubes and weighted with an analytical balance. Data on retreatment time and apical extrusion were statistically analyzed with the Kruskal-Wallis test (p < 0.05). Working length was achieved in all the retreated samples. The removal of root filling material resulted significantly faster with the Jeni mode (p < 0.001), and the difference was significant for the removal of both filling materials (p < 0.05). No significant differences on debris extrusion between single cone and experimental obturators groups were noted (p > 0.05), and no significant differences between kinematics (continuous rotation vs. Jeni motion) were observed (p > 0.05). All the tested retreatment strategies lead to an extrusion of material from the apex, and the weight of apically extruded debris was similar. The use of the innovative CanalPro Jeni kinematics accelerates the time for the removal of root filling materials.

In-Depth Metallurgical and Microstructural Analysis of Oneshape and Heat Treated Onecurve Instruments.

OBJECTIVE: To define surface, mechanical, microstructural and metallurgical features of conventional One-Shape (OShape) and heat-treated OneCurve (OCurve) nickel-titanium instruments. METHODS: Instruments were analysed by scanning electron microscopy (SEM) on new instruments and after simulated clinical use (SCU). Cyclic fatigue testing was performed and the number of cycles to fracture (NCF) and the length of the fractured instruments were measured (Mann-Whitney test). Fractured instruments during cyclic fatigue testing were then inspected by SEM fractographic analysis. Field emission gun scanning scanning electron microscopy (FEG-SEM), energy-dispersive X-ray spectroscopy (EDX) and micro-Raman spectroscopy were used to assess alloy surface chemistry. Focused ion beam (FIB) was performed to analyse the oxide layer on the surface of OCurve before and after SCU. X-Ray diffraction (XRD), metallographic evaluation and differential scanning calorimetry (DSC) were used to determine martensitic/austenitic phase transformation temperatures. RESULTS: SEM observations on new instruments revealed a smooth regular surface with flattened milling grooves. No wear features were detected after SCU. OCurve exhibited a higher cyclic fatigue resistance (P<0.05), slower crack propagation and a surface layer of TiO2. Metallographic analysis and XRD showed the prevalence of martensitic grains on OCurve instruments that were stable at body temperature as confirmed by DSC analysis. Furthermore, DSC demonstrated a shift in the temperature transformation ranges suggesting an increase of martensite phase in autoclaved OCurve instruments. CONCLUSION: Heat treatment processes were confirmed as a valid enhancement of the properties of the new generation NiTi instruments. OCurve presented a significant improvement over OShape regarding both mechanical and metallurgical characteristics.

Combining apical torsional load and cyclic fatigue resistance of NiTi instruments: New approach to determine the effective lifespan of rotary instruments.

In the described proof-of-principle experiments, we introduced a novel testing device to investigate how different concurrent torsional loads influence the cyclic fatigue (CF) resistance of a nickel-titanium (NiTi) instrument. The device was designed to test CF resistance of NiTi files with a standardized load on the apical 5 mm; a movable cylinder controlled by a lever provided a uniform real-time load. Thirty-three NiTi instruments 25.04 (F360, Komet, Lemgo, Germany) were rotated until fracture at 30° curvature under three different torsional loads (n = 11 each); Group A: 2.5 Ncm; Group B: 5 Ncm; Group C: 10 Ncm. anova, multiple comparisons Tamhane tests, regression and Kaplan-Meyer analysis were performed to contrast means. Resistance to cyclic fatigue differed significantly among groups (P = 0.0001). Increased torsional loads led to a decrease in time to failure. An inverse correlation (r = -0.721, P = 0.001) was observed between time and torsional load, with higher torsional loads correlated to shorter times to fracture.

Factors Affecting Soft and Hard Tissues Around Two-Piece Transmucosal Implants: A 3-Year Prospective Cohort Study.

PURPOSE: This 3-year study aimed to evaluate hard and soft tissue modification around a two-piece implant characterized by a transmucosal hyperbolic neck in healthy consecutive patients with a need for single-tooth replacement. MATERIALS AND METHODS: Two-piece implants (n = 66) were placed with a flapless technique in 56 patients (27 men; 29 women; mean age 55 ± 9 years): 16 immediately after root extraction (immediate group), 20 after 8 to 12 weeks (early group), and 30 after 10 or more months (delayed group). The transmucosal hyperbolic neck was exposed 1 to 1.5 mm above gingival level. Customized abutments were positioned 3 months later with the implant-abutment connection located approximately 1 to 1.5 mm above soft tissue level. Provisional cemented resin crowns were designed with the finishing line at the hyperbolic neck and then positioned to avoid excessive compression of soft tissue, to guide gingival contours. Twenty days later, a definitive metal-ceramic crown was cemented. In all patients, the gingival biotype (thin or thick) was also evaluated. The primary outcomes were as follows: 36-month implant survival rate, peri-implant marginal bone level (MBL, in mm) changes observed in single-blind on radiographs at 1, 3, 6, 12, 24, and 36 months (T1, T3, T6, T12, T24, and T36), and pink esthetic score (PES) at T6, T12, and T36 to analyze soft tissue adaptation after loading and crown application. The secondary outcomes were as follows: plaque score and bleeding on probing (BOP). Linear regression models and multilevel mixed logistic regression were used to detect any statistical difference of MBL according to operative parameters. Kruskal-Wallis one-way analysis of variance (ANOVA) on ranks was performed to assess statistical differences of PES at T6, T12, and T36. RESULTS: The survival rate was 100%. The dropout rate was 1.79%. No infections, mucositis, or peri-implantitis were reported. Implants placed in thick-biotype tissues showed a statistically different lower bone loss at 36 months with respect to the thin biotype (P < .05). At 36 months, the early group showed lower bone loss compared with the delayed group (P < .05). Multilevel mixed logistic regression revealed that gingival biotype was the parameter that was most related to MBL variations (P = .025). The PES value (mean ± SD) at T6 was 10.76 ± 1.19 (median: 11; range: 8 to 13; IQR: 10 to 12). The values statistically increased at T12 and T36, where the mean values were 11.76 ± 1.10 (median: 12; range: 9 to 13; IQR: 11 to 12) and 11.83 ± 1.03 (median: 12; range: 9 to 14; IQR: 11 to 13). CONCLUSION: MBL and soft tissue clinical parameters measured around two-piece hyperbolic-neck implants were stable during the 3-year follow-up and free from complications. The exposure of the hyperbolic neck for 1.0 to 1.5 mm allowed a flapless one-stage surgery, which supported fast adaptation of the soft tissues, evidenced by high PES values and low percentages of BOP. The results from the study imply a new simple approach in the clinical management of gingival and bone tissue.

Secondary Root Canal Treatment with Reciproc Blue and K-File: Radiographic and ESEM-EDX Analysis of Dentin and Root Canal Filling Remnants.

Secondary root canal treatment requires the complete removal of filling materials with different chemical-physical properties. A newly developed single-use NiTi instrument (Reciproc Blue, RB) may be more effective in root canal retreatment. The aim of the present study was to evaluate morphology and composition of remnants after retreatment with RB compared to traditional K-File technique, in canals obturated with Thermafil/AH Plus. Twenty-four single-rooted human teeth were shaped with NiTi obturated with AH-Plus/Thermafil and retreated using RB NiTi instruments or manual K-Files. Radiographs were taken to evaluate endodontic space and radiopacity of residual filling-material before/after procedures. After retreatment, samples were longitudinally split and observed by environmental scanning electron microscopy connected to energy dispersive X-Ray spectroscopy (ESEM-EDX) to analyze the debris/remnant position, microchemistry, and dentinal surface morphology. Time for retreatments was recorded and compared using one-way ANOVA (p-value = 0.05). Radiopaque filling residuals were found in both groups. RB system resulted statistically faster than manual K-File in retreatment procedure (p < 0.001). Root canal space radiographic appearance obtained after retreatment with RB was wider than K-File (p < 0.05). ESEM-EDX revealed 4 different morphological dentin area. Area-1: debris-free with typical Ca, P, and N composition of dentin and detected in 70% of the surface. Area-2: presence of deproteinized smear layer free from N and debris in 15% of the surface. Area-3: a thick packed smear layer N-free and with fine debris consisting of trace elements from sealer in 10% of the surface. Area-4: packed with debris and trace elements. No difference was observed between both instruments regarding root canal space appearance and ESEM-EDX analysis. Both systems were able to remove filling material but created a dentine morphology composed of packed debris and filling materials embedded into the smear layer. Dentin surface composition resulted in collagen depleted by irrigation procedures. The reciprocating system required less time to complete retreatment.

A Multilevel Analysis of Platform-Switching Flapless Implants Placed at Tissue Level: 4-year Prospective Cohort Study.

PURPOSE: To evaluate the factors affecting peri-implant marginal bone level of single platform-switched implants with a smooth neck placed at gingival level (tissue level) using a flapless technique. MATERIALS AND METHODS: Consecutive healthy patients requiring dental implant rehabilitations were enrolled in this study. Titanium implants with a zirconium-oxide-blasted surface and a platform-switch neck tulip configuration were used. Loading was performed 3 months after insertion with a provisional resin crown and after approximately 15 days with a definitive ceramic crown. Peri-implant marginal bone level (MBL) was measured on periapical radiographs at 1, 3, 6, 12, 24, 36, and 48 months by a blinded assessor. The following parameters were evaluated: location (maxillary/mandibular), position (anterior/posterior), sex (male/female), smoke (yes/no), implant placement timing (immediate, early, delayed), gingival thickness (thin/thick), endodontically treated adjacent teeth (yes/no), and diameter (3.8/4.25/5.0 mm). Multilevel analyses exploring factors associated with MBL at 36 and 48 months were performed. RESULTS: A total of 76 patients (42 women, 34 men; mean age: 55.6 ± 10.7 years) received 128 implant rehabilitations. The survival rate was 98.4%. MBL displayed an initial increase during the first months from insertion (preload period). Cumulative mean MBL at T48 was 0.99 ± 0.68, which was not statistically significant from the values at T24 to T36 (P > .05). Mandibular location, delayed implants, and presence of adjacent endodontically treated teeth showed higher bone loss at 36 months (P < .05). Interestingly, at 48 months, only implant placement timing showed statistically significant differences. Delayed implants showed increased bone loss compared with both early and immediate groups (P < .05). Multilevel analysis confirmed the statistical significance of implant location (P = .031; 95% CI: 0.031 to 0.659), endodontically treated adjacent teeth (P = .001; 95% CI: -1.228 to 0.859), and implant placement (P = .045; 95% CI: 0.003 to 0.337) as factors affecting MBL at 36 months. All the investigated parameters, with the only exception being the implant placement group (P = .020; 95% CI: 0.334 to 1.432), were not statistically significant at 48 months (P > .05). CONCLUSION: Platform-switched implants placed nonsubmerged with a flapless approach showed a reduced bone loss progression in the first 4 years, as MBL remained stable at longer times (36 and 48 months). Implants placed with early and immediate timing showed reduced bone loss compared with delayed implants.

Maryland-bridge application as a suitable technique to preserve marginal bone level of not-submerged supracrestal implants.

BACKGROUND: One to 6 months after implant placement is a critical time/period responsible for crestal bone loss that may affect implant osseointegration. The study aims to explore the effectiveness of provisional adhesive Maryland-bridge (AMB) applied to prevent marginal bone level (MBL) around implants placed in edentulous crestal bone in posterior area during osseointegration period. METHODS: Healthy, non-smoker patients (N.=18) were included in the study. Titanium implants were placed nonsubmerged (i.e. tissue-level) with cover screws at gingival level in edentulous crestal bone with flapless technique. Nine patients randomly received an AMB, while 9 patients did not receive any AMB. Each AMB remained in place for 3 months and removed before impression. After 3 months abutments were applied, and provisional resin crowns cemented and definitive metal-ceramic crowns were cemented after 2-3 months. Periapical Rx were taken using paralleling technique before and after implant insertion, at 1, 3 months (pre-loading time) and after 6 months (post-loading time). MBL was evaluated in double-blind on scanned periapical radiographs and assessed at mesial and distal side of implants (M-MBL and D-MBL). Area of bone loss on mesial and distal side of implants (Area-M and Area-D) and Cervical Enamel Junction migration of mesial and distal adjacent teeth were also measured (CEJ-M and CEJ-D). Linear regression models were fitted to evaluate the existence of any significant difference. RESULTS: Two drop-out was observed in AMB group. A total of 16 patients completed the study. After 6 months, all implants were safe and free from complications. AMB group showed the most stable MBL at 1-6 months, statistically different from non-AMB and resulted in a reduced crestal bone loss from baseline compared to Non AMB group. Area-M and Area-D were not statistically different between the groups. CEJ-M and CEJ-D were stable in both groups. CONCLUSIONS: The use of Adhesive Maryland Bridge to protect non-submerged post-extractive implants is a safe procedure that prevents bone loss around implants and preserve the 3D architecture of crestal bone ridge.

Rehabilitation of anterior maxilla with a novel hyperbolic profile transmucosal implant in elderly patients.

BACKGROUND: This study aims to evaluate soft and hard tissues response of a two-piece implant placed nonsubmerged in elderly patients' anterior maxilla. Marginal bone level and Pink Esthetic Score (PES) were evaluated up to 24 months. METHODS: Twelve healthy consecutive patients (mean age 65.8±5 years; 65.5 median) were included in the study. Implants were inserted with flapless technique after 3 months or immediately after extraction. The smooth machined neck of the implant was characterized by a hyperbolic neck which follows biologically oriented preparation technique (BOPT) principles. A customized abutment and a provisional resin crown was positioned with care to avoid excessive soft tissue compression after 3 months, according with BOPT technique. A definitive ceramic crown was positioned after approx. 4 months. RESULTS: After 24 months all implants were stable and osseointegrated. PES improved at 6 and 12 months recalls, remaining stable at 24 months, indicating a healthy soft and hard tissue response. No complications were observed. Impression procedures and provisional/definitive crown cementation resulted simple and free from complications. The hyperbolic profile allowed the preparation of prosthetic crown free from any gingival tissue pressure to create the adequate soft tissue contour. CONCLUSIONS: The use of hyperbolic profile implant associated with the transmucosal (not-submerged) technique is a safe procedure that allow the preservation of soft and hard tissue also in elderly patients.

Correction to: The fate of root canals obturated with Thermafil: 10-year data for patients treated in a master's program.

The author names in the original version of this article were inadvertently interchange. Correct presentation of author names is reflected here.

Impact of a modified motion on the fatigue life of NiTi reciprocating instruments: a Weibull analysis.

OBJECTIVES: To evaluate the impact of a modified motion on the fatigue life of four brands of nickel-titanium (NiTi) reciprocating instruments. MATERIALS AND METHODS: Cyclic fatigue (CF) resistance of 160 instruments was evaluated in an artificial stainless-steel canal (90° angle, 5-mm radius of curvature). WaveOne and WaveOne Gold (Denstply Maillefer, Baillagues, Switzerland) and Reciproc and Reciproc Blue (VDW, Munich, Germany) were tested with two different motions: (1) X-Smart Plus (Denstply Maillefer) endodontic motor and (2) a 4:1 contra-angle with an experimental motion (EVO) with different rotation angles and based on a sinusoidal acceleration. Motions with X-Smart Plus and EVO were recorded and analyzed at a reduced speed with VLC Media Player software for a more accurate analysis. Mean half-life, beta, and eta Weibull parameters were determined and compared. RESULTS: Reciproc Blue resulted the most resistant instruments either with EVO or X-Smart. WaveOne Gold lasted significantly longer than WaveOne with EVO (probability of 91%) while no significant differences were found with X-Smart. Considering NCF, Reciproc, WaveOne Gold, and Reciproc Blue lasted significantly longer with EVO (probabilities of 66%, 80%, and 89% respectively). WaveOne Gold showed the highest beta parameter. CONCLUSIONS: The experimental motion was found to have a positive impact on fatigue lifetime of reciprocating instruments. CLINICAL RELEVANCE: Current findings provide insight for future improvements in the clinical use of reciprocating files. Experimental motions may be considered when searching for additional strategies in order to increase the safer use of NiTi files during endodontic procedures.

The fate of root canals obturated with Thermafil: 10-year data for patients treated in a master's program.

OBJECTIVES: Retrospective description of the 10-year success rate of endodontic treatments with Thermafil (TF). MATERIALS AND METHODS: Patients treated by postgraduate students in an Endodontics Master's Program (2006-2008) were enrolled. All treated root canals were filled with TF and AH Plus. Teeth satisfying the inclusion criteria (206 teeth in 89 patients) were reexamined clinically and radiographically to estimate a 10-year survival and periapical health. Demographic and medical data were registered; collected information included pre-, intra-, and postoperative variables. Teeth were classified as "healthy" (PAI ≤ 2 in absence of signs/symptoms), "endodontically diseased" (presenting at least one of the following: PAI ≥ 3, signs/symptoms, retreated in the course of the follow-up, or extracted for endodontic reasons), or "non-endodontically diseased" (extracted for non-restorable fractures or periodontal disease). For teeth lost during the 10-year follow-up, details and reason of extraction were analyzed. Two PAI-calibrated examiners assessed outcomes blinded to preoperative status. Bivariate and multilevel analyses were performed (α level set at 0.05). RESULTS: At 10 years, 179 (87%) teeth survived and 27 were extracted: 20 for non-endodontic reasons (excluded from success analysis) and 7 for endodontic reasons (considered "endodontically diseased"). Multilevel analysis revealed that the probability of extraction was increased by the presence of preoperative pain (odds ratio = 6.720; 95% confidence interval, 1.483-30.448) and by maxillary location (odds ratio = 2.950; 95% confidence interval, 1.043-8.347). Concerning periapical status, 159/186 teeth (85%) were assessed as "healthy." Multilevel analysis confirmed that maxillary location (odds ratio = 3.908; 95% confidence interval, 1.370-11.146), presence of flare up (odds ratio = 9.914; 95% confidence interval, 2.388-41.163), and fracture occurrence (odds ratio = 35.412; 95% confidence interval, 3.366-372.555) decreased the odds of healing, respectively. CONCLUSIONS: After 10 years, teeth filled with Thermafil in a specialist master's program presented a survival and a periapical health comparable to cohorts where root canals were filled with other obturation techniques. CLINICAL RELEVANCE: Carrier-based techniques provide time savings for clinicians while satisfying clinical quality criteria for the root filling and consequently the clinical outcome.

Outcome of secondary root canal treatment filled with Thermafil: a 5-year follow-up of retrospective cohort study.

OBJECTIVES: The aim of the present retrospective cohort study was to assess the 5-year outcome and survival of secondary root canal treatments (2°RCT), exploring the influence of pre-, intra-, and post-operative variables. MATERIALS AND METHODS: One hundred thirty-two endodontically retreated teeth were radiographically and clinically re-examined after 5 years. 2°RCT had been performed during a Masters program following standardized protocols and filled with AH Plus/Thermafil (TF). Pre-, intra-, and post-operative data were collected. The 5-year outcome was blindly evaluated and categorized as healed/diseased on the basis of the periapical index. Bivariate analysis and chi-square test evaluated the association between outcome and 31 demographic/clinical parameters. Multilevel analysis was performed at both patient and tooth level. Statistical significance was calculated at 5% level. RESULTS: At 5-year evaluation, survival rate was 80% with 7.5% lost for endodontic reasons. Eighty-three percent of the teeth were classified as healed. Multilevel analysis identified significant predictors of increased survival: female gender (p = 0.012), absence of a pre-operative metal post (p = 0.017), conservative apical preparation (diameter size < #35) (p = 0.039), teeth restored with a crown (p = 0.009), and final PAI (after 5 years) ≤ 2 (p = 0.001). Multilevel analysis identified as predictor healing: not being a smoker (p = 0.048) and conservative apical preparation < size #35 (p = 0.037). CONCLUSIONS: Outcome of 2°RCT filled with Thermafil was successful at 5 years, showing a high rate of survived and healed teeth comparable to that reported previously for other obturation techniques. CLINICAL RELEVANCE: Present findings confirm 2°RCT as a valid therapeutic option to retain natural teeth.

Immediate Early and Delayed Implants: A 2-Year Prospective Cohort Study of 131 Transmucosal Flapless Implants Placed in Sites With Different Pre-extractive Endodontic Infections.

INTRODUCTION: To evaluate clinical outcome of early, immediate, and delayed transmucosal implants placed in patients affected by acute/chronic endodontic lesions. MATERIALS AND METHODS: Eighty-five consecutive patients received 131 titanium implants with zirconium-oxide blasted surface. Pre-extractive diagnosis represented the main criteria for implant placement timing, following "best treatment" criteria. Implants were placed with flapless transmucosal technique. Hopeless teeth with chronic periapical lesions received atraumatic extraction, and an implant was immediately placed (Immediate Group, n = 29). Teeth with acute periapical lesion/abscess were extracted and implants placed after 8 to 12 weeks (Early Group, n = 29). Implants placed 10- to 12-month after extraction constituted the control group (delayed group, n = 73). Implants were loaded 3 months after insertion with provisional resin crowns and after approximately 15 days with definitive ceramic crowns. Marginal bone loss (MBL) was measured in a single-blind manner on periapical radiographs at 1, 3, 6, 12, and 24 months. RESULTS: Multilevel analysis described exploring factors associated with MBL. Survival rate was 100%. MBL after 24 months was 0.78 ± 0.70 (95% confidence interval [CI]: 0.20 to -1.37) at immediate, 0.48 ± 0.70 at early (95% CI: -0.006 to -0.961), and 1.02 ± 1.01 (95% CI: 0.61 to -1.43) at delayed groups. Implant groups (immediate/early/delayed) and location (maxillary/mandibular) showed statistically significant results. Early group showed the lowest MBL values. The immediate group demonstrated less MBL than the delayed group. CONCLUSION: Early implant placement technique preserves periimplant marginal bone level more than immediate and delayed techniques.

Long-term outcome of non-surgical root canal treatment: a retrospective analysis.

This study investigated the long-term clinical outcome of root canal treatment. 240 root-treated teeth (n = 61 patients) were initially classified on the basis of radiographic presence/absence of initial apical periodontitis (IAP) and clinical data. The final outcome measure was the periapical healing (healed/disease). The outcome at 6-9 months was correlated with the outcome at 10 years following treatment. Prognostic factors for the periapical healing were assessed. Extraction data were recorded. Univariate and multivariate logistic regression analysis was used to identify risk indicators for apical periodontitis (AP) development. Chi-square analysis was performed to evaluate a possible relationship between the 6-9 months outcome and the final outcome related to IAP. Mean observation time was 14 ± 3.7 years. Survival rate was 84.6% and healing rate was 79% (10-19 years). Predictors of outcome (p < .05) were considered statistically significant. Multivariate logistic regression analysis showed that initial pulpal and periapical status and the quality of root canal filling as assessed two-dimensionally were independent predictors of outcome. The 6-9 months evaluation appears to be an indicator for the final outcome of primary root canal treatment both in the presence and in the absence of IAP. An initial radiolucency associated with an unsatisfactory quality and extent of root canal filling significantly diminishes the possibility of achieving long-term radiographic success. For those with uncertain healing at 6-9 months (91%), clinicians should consider the high healing rate when estimating the prognosis and adjust the decision making accordingly.

Wear and metallographic analysis of WaveOne and reciproc NiTi instruments before and after three uses in root canals.

Reciprocating instruments made from M-wire alloy have been proposed to reduce the risk of fracture. No information is available on the surface alteration after single and multiple uses in root canals. Two reciprocating NiTi instruments were used on extracted teeth up to three times. ESEM/EDS analysis was conducted to determine defects, alterations, and wear features of the apical third of instruments and metallographic analysis was performed on the cross-section of new and used instruments to compare alloy properties. Topography of apical portion was evaluated by AFM before and after uses. Extracted single-rooted teeth were divided into two groups and instrumented according to the manufacturer's recommendations with: (A) WaveOne Primary and (B) Reciproc R25. Each group was divided into three subgroups according to the number of canals instrumented: 1, 2, and 3, respectively. Chi square test was performed to verify homogeneity of defects distribution and GLM to evaluate the differences of RMS at baseline and after use for both groups (α level 0.05). No instrument fractured and no spiral distortions were observed under optical microscope even when the number of uses increased. Not significant differences were found for WaveOne and Reciproc. Blades presented a wrapped portion in WaveOne group and a more symmetrical feature in Reciproc group. Metallographic analysis revealed in both groups the presence of twinned martensitic grains with isolated flat austenitic areas. Both instruments demonstrated limited alteration, such as tip deformation and wear. This study confirmed the safe clinical use of both instruments for shaping multi-rooted teeth.