Intraradicular reinforcement of traumatized immature anterior teeth after MTA apexification.

This review article describes the methods and clinical recommendations for reinforcing traumatized anterior immature teeth with pulp necrosis treated with mineral trioxide aggregate (MTA) apexification. Traumatic injury can cause pulp necrosis and incomplete root formation in immature teeth. MTA apexification is the treatment of choice for necrotic immature teeth, particularly during the middle or late stages of root development. MTA apexification has a high success rate; however, failures due to cervical or root fractures occasionally occur. The risk of fracture is higher in immature teeth with thin root dentin, particularly those with external root resorption. Furthermore, the loading force from any parafunctional habit also increases fracture risk. Therefore, intra-radicular reinforcement may be necessary after MTA apexification. In vitro, intraradicular restoration with a resin composite/core build-up material or a prefabricated fiber post demonstrated better root reinforcement than root canal obturation materials (i.e., gutta-percha and sealer). However, the root-reinforcement effect of MTA orthograde filling in the entire root canal remains unclear. In vivo, the survival of fractured teeth with intraradicular restorations (resin composite/core build-up material or prefabricated fiber posts) is extremely high. Moreover, the survival of teeth with gutta-percha/sealer obturation or MTA orthograde filling and restoration with resin composite extending into the cervical third of the root canal approximately 1-2 mm below the cemento-enamel junction is acceptably high. Based on this evidence, the remaining tooth/root structure and loading force should be carefully examined when considering intra-radicular reinforcement of immature anterior teeth treated with MTA apexification.

Influence of Different Post-endodontic Restorations on the Survival Rate Against Fracture of Endodontically Treated Anterior Teeth Affected by Cervical Lesions with Pulpal Involvement: A Retrospective Clinical Study.

OBJECTIVE: To compare the survival rate against fracture of endodontically treated anterior teeth (ETT) affected by cervical (class V) lesions with pulpal involvement restored with resin composite or a post/core and crown, and to identify the prognostic factors for fracture. METHODS: Dental records and radiographs of ETT affected by cervical lesions with pulpal involvement restored with resin composite or a post/core and crown during a recall period from 2009-2022 were selected according to the inclusion and exclusion criteria. The number of tooth fracture, the restorability after fracture and any possible risk factors were identified. The survival rate against ETT fracture were analyzed and com- pared between the two restoration groups by Kaplan-Meier survival analysis and the Tarone-Ware test. Non- proportional hazard models were used to identify the prognostic factors. The sub-analysis in each restoration group was also performed. RESULTS: The study comprised 175 ETT restored with resin composite (n=125) or a crown (n=50). With a mean recall period of 32.9+-15.8 months, the survival rate against ETT fracture with resin composite (85.6%) was not significantly different from those with a crown (88%) (p≥0.05). The most frequent mode of fracture was crown-root fracture, which accounted for 78% and 83.30% of the fractures in the resin composite and crown groups, respectively. A significant prognostic factor for ETT fracture affected by cervical lesions with pulpal involve- ment was additional tooth structure loss from a class III, class IV or another class V lesion on the opposite side (p<0.05). The ETT affected by cervical lesions with pulpal involvement combined with additional tooth structure loss had a 7.25-fold higher risk of fracture than those with single-surface affected by cervical lesions with pulpal involvement (hazard ratio [HR] = 7.25; 95% confidence interval [CI], 1.68-31.30). The sub-analysis in the crown and resin composite groups revealed that the survival rates of ETT with single-surface affected by cervical lesions with pulpal involvement was 100% and 96.15%, respectively, which were significantly higher than those of ETT with additional tooth loss at 80.65% and 78.08%, respectively (p<0.05). CONCLUSION: With a mean 33-month recall period, the survival rate against ETT fracture affected by cervical lesions with pulpal involvement restored with resin composite or crown were not significantly different. Additional tooth structure loss was a significant prognostic factor for fracture.

Current Management of Dens Evaginatus Teeth Based on Pulpal Diagnosis.

INTRODUCTION: Dens evaginatus (DE) is a dental anomaly with a supernumerary tubercle projection that typically contains dentin and pulp tissue. However, the tubercle projection can fracture, exposing the dentin and potentially the dental pulp, which induces pulpal diseases. Managing DE should be primarily based on the clinical diagnosis of the pulp. METHODS: The literature search in prevalence, prophylaxis, and management of dens evaginatus was performed in PubMed database as well as by manual search, in which the related contents were collected and descriptively analyzed. RESULTS: Of the 264 searched literatures, 62 articles were included for this scoping review. The prophylactic management of the tubercle of DE teeth with a normal pulp should be performed as early as possible by the prep-and-fill technique or the reinforcement technique to preserve tooth vitality and continued root development, with the former reported to be superior compared with the latter. Furthermore, DE teeth with reversible pulpitis should be managed with the prep-and-fill technique. For DE teeth with irreversible pulpitis, vital pulp therapy, ie, partial or full/coronal pulpotomy, should be considered when the pulpal inflammation is limited to the coronal pulp to preserve the vitality of the radicular pulp that induces apexogenesis. A pulpectomy should be performed if the pulpal inflammation has progressed into the radicular pulp. For DE teeth with pulpal necrosis (or after pulpectomy) and immature roots, mineral trioxide aggregate apexification or regenerative endodontic procedures are the treatment options. For DE teeth with pulpal necrosis and complete root formation, nonsurgical root canal treatment is the treatment of choice. A flow chart of the decision-making for managing DE teeth based on pulpal diagnosis is proposed. CONCLUSION: DE teeth should be properly managed, by prophylaxis or treatment, depending on pulpal diagnosis and related factors.

Association between Clinical/Radiographic Characteristics and Histopathological Diagnoses of Periapical Granuloma and Cyst.

OBJECTIVE: The aim of this study was to determine the association between clinical/radiographic characteristics and histopathological diagnoses of periapical granuloma and cyst obtained from the teeth treated with endodontic microsurgery. MATERIALS AND METHODS: The clinical, radiographic (periapical and cone-beam computed tomography), and histopathological data were collected from patients' dental records of endodontic microsurgery on the teeth with periapical lesions. These lesions were histopathologically diagnosed as either granuloma or cyst, at the Endodontic Clinic, Faculty of Dentistry, Mahidol University, Bangkok, Thailand, from 2016 to 2021 according to inclusion and exclusion criteria. The data were analyzed using bivariate analysis and a multinomial logistic regression at a significance level of p-value less than 0.05. RESULTS: A total of 83 patients (58 females and 25 males) with an average age of 45 to 49.5 years old met the criteria including 68 periapical granulomas (81.9%) and 15 periapical cysts (18.1%). A periapical lesion involving multiple teeth in a periapical radiograph was significantly associated with the histopathological diagnosis of periapical cyst (p < 0.05). Such periapical lesion was six times more likely to be periapical cyst than periapical granuloma. CONCLUSIONS: A significant factor for predicting periapical cyst from periapical granuloma was the presence of a periapical lesion with multiple-teeth involvement in a dental radiograph.

Shaping ability of non-adaptive and adaptive core nickel-titanium single-file systems with supplementary file in ribbon-shaped canals analysed by micro-computed tomography.

This study compared shaping ability between two single-file systems and before/after using supplementary file in untouched area, volume of removed dentin, maximum cut depth (the highest cut depth by main file) and remaining thinnest dentin (the thinnest root dentin after preparation). Ribbon-shaped distal canals of mandibular molars were prepared with non-adaptive core (WaveOne Gold) or adaptive core (XP-endo Shaper) files (n = 15/group) and additionally prepared with a supplementary file (XP-endo Finisher), and the shaping ability was investigated using micro-computed tomography. XP-endo Shaper group demonstrated significantly less overall untouched area than WaveOne Gold group (38.21 ± 6.98% vs. 47.68 ± 9.16%) (p < 0.05). No significant difference was detected between XP-endo Shaper and WaveOne Gold groups in volume of removed dentin (1.85 ± 0.53 vs. 1.66 ± 0.33 mm3 ), maximum cut depth (0.10-0.28 vs. 0.10-0.29 mm) and remaining thinnest dentin (0.66-0.80 vs. 0.78-0.88 mm). Supplementary XP-endo Finisher treatment significantly decreased untouched area (11%-23% reduction) (p < 0.05) with minimally cut root dentin (0.01-0.02 mm).

In vitro bactericidal efficacy of a new triple antibiotic paste formulation against Enterococcus faecalis biofilm.

The aim of this study was to evaluate the bactericidal efficacy on Enterococcus faecalis biofilm of a novel, low-concentration triple-antibiotic paste (TAP-L2) in propylene glycol/carboxymethylcellulose vehicle (VEH-2), a ready-to-use prototype, compared with two currently used products; a low-concentration (TAP-L1) and a high-concentration paste (TAP-H1) mixed in macrogol/propylene glycol vehicle (VEH-1). Sixty-two root canals were infected with E. faecalis biofilm, medicated with (a) TAP-L1, (b) TAP-L2, (c) TAP-H1, (d) VEH-1 or (e) VEH-2 (n = 10) and incubated for 21 days. Live/dead assays were performed using confocal laser scanning microscopy (CLSM), and dead bacteria (%) were calculated. The TAP-H1 group demonstrated the highest dead bacteria (67.54 ± 2.38%), which was significantly higher than the TAP-L2 and TAP-L1 groups (56.85 ± 7.11% and 54.23 ± 10.19%) (p < 0.05). The TAP groups demonstrated significantly higher dead bacteria than the VEH-1 and VEH-2 groups (47.51 ± 6.41% and 45.14 ± 8.28%) (p < 0.05). The ready-to-use TAP-L2 had antibacterial activity comparable to TAP-L1, both of which were lower than TAP-H1.

Gap volume and sealer penetration of C-shaped root canals obturated with cold hydraulic technique and calcium silicate sealer.

This study compared the gap volume and sealer penetration in C-shaped root canals prepared with adaptive core rotary files and obturated with cold hydraulic compaction using calcium-silicate sealer, warm vertical hybrid compaction, or lateral compaction using epoxy-resin sealer. Thirty-six extracted mandibular molars with pulpal floor configuration Types I and III were used. The teeth were prepared using XP-Shaper and XP-Finisher and obturated with: group 1: cold hydraulic compaction/calcium silicate, group 2: warm vertical hybrid compaction/epoxy resin, or group 3: lateral compaction/epoxy resin. The gap volume was evaluated using µ-CT. The sealer penetration depth and area were evaluated using confocal laser scanning microscopy. The gap volume in groups 1, 2, and 3 was 0.82%, 0.24%, 0.80%, respectively, which were not significantly different (p > 0.05). The gap volumes in the obturated C-shaped canals were not significantly different among the CHC/CSBS, WHC/ERS, or LC/ERS groups. CHC/CSBS was the most convenient technique.

Outcomes and Predisposing Factors of Two Prophylactic Treatments in Dens Evaginatus Premolars: A Retrospective Study.

INTRODUCTION: Dens evaginatus (DE) in premolars may contain a pulpal extension inside the occlusal tubercle. DE prophylaxis should be performed to prevent pulpal exposure due to tubercle fracture. The aim of this study was to compare the outcomes of 2 prophylactic treatments, that is, prep and fill (PF) and reinforcement (RF), in DE premolars based on clinical and radiographic data, and to identify the predisposing factors. Furthermore, DE prevalence was reported. METHODS: The DE premolar data were collected from dental and radiographic records at the Faculty of Dentistry, Mahidol University, and Bangkok Hospital, Thailand during 2000-2020. Their prevalence and characteristics were determined. Only DE teeth treated with PF or RF prophylaxis were included. Outcomes and possible predisposing factors of the 2 prophylactic groups were evaluated and statistically analyzed. RESULTS: Initially, 303 DE premolars from 110 patients were identified, with the highest prevalence observed in second mandibular premolars (37.21%). The prevalence of contralateral, same quadrant, and opposite arch DE premolars was 50.91%, 39.09%, and 34.55%, respectively. A total of 216 DE teeth met the criteria with an ∼82% recall rate, with 190 and 26 premolars treated by PF and RF, respectively. With mean recall periods of ∼31 and 23 months, the outcomes in the PF and RF group were 95.79% and 80.77% success, respectively, which were significantly different (P = .01). No significant predisposing factor was found. CONCLUSION: Prophylactic treatment in DE premolars with PF provided a significantly higher success rate than those treated with RF.

Comparison of the Survival Rate Against Fracture of Endodontically Treated Premolars with Exposed Cervical Lesions Restored with Crowns and Resin Composites: A Retrospective Study.

OBJECTIVE: The purpose of this study was to evaluate the effect of coronal restorations on the survival rates against fracture of endodontically treated premolars with exposed cervical lesions and to identify the prognostic factors for fracture. METHODS: Data of the endodontically treated premolars with exposed cervical lesions restored with resin composites or crowns between 2011 and 2020 were collected. The presence of a fracture was recorded, and the possible prognostic factors were recorded. Statistical analyses were performed, with a significance level of P<0.05, using a Kaplan-Meier survival analysis, log-rank tests, and Cox proportional hazard models were used to identify the prognostic factors. RESULTS: The survival rates against fracture were not significantly different between the teeth restored with crowns (93.3%) or resin composites (86%) (P≥0.05). A high frequency of non-restorable fractures was observed in both groups. Crestal bone reduction to the middle-third of the root was identified as the significant prognostic factor (P<0.05). CONCLUSION: For endodontically treated premolars with exposed cervical lesions, resin composite restorations provided a high comparable survival rate that was comparable to that of crowns. A higher risk of fracture was found in endodontically treated premolars with crestal bone loss to the middle-third of the root.

Radiopacity of Portland Cement and Calcium Silicate-Based Cement with Different Mixed Ratios of Radiopacifiers.

OBJECTIVE: The present study aimed to compare the radiopacity of Portland cement (PC) or calcium silicate-based cement (CSC) with different mixed radiopacifiers [bismuth oxide (BO)/ tantalum oxide (TO) and zirconium oxide (ZO)/barium sulfate (BS)] in a ratio of 1: 1 or 1: 2, with the 3 mm aluminium thickness (mmAl) acceptable value of ISO 6876: 2012. METHODS: PC and CSC mixed with different ratios of radiopacifiers were evaluated. One of high radiopacity radiopacifiers, BO or TO, was mixed with one of low radiopacity radiopacifiers, ZO or BS, in ratio of 1: 1 and 1: 2. PC or CSC powder, 1.6 g, was added into 0.4 g mixed radiopacifiers. Disc-shaped specimens of 1-mm thickness were prepared by mixing PC or CSC powder containing radiopacifiers with distilled water; the radiopacity was measured according to ISO 6876: 2012. One-way ANOVA/Tukey's test and Welch ANOVA/Games-Howell test were used to compare the radiopacity among the groups. The significance level was set at 0.05. RESULTS: PC groups had a higher radiopacity than CSC groups with the same radiopacifiers and ratio. BO groups showed higher radiopacity than TO groups. The groups with 1: 1 ratio provided a higher radiopacity than 1: 2 ratio groups (P>0.05). CONCLUSION: All tested radiopacifiers revealed adequate radiopacity ranging from 3.05-4.25 mmAl, except CSC with TO/BS in ratio of 1: 2.

Retrospective study of fracture survival in endodontically treated molars: the effect of single-unit crowns versus direct-resin composite restorations.

OBJECTIVES: This study was conducted to compare the post-fracture survival rate of endodontically treated molar endodontically treated teeth (molar ETT) restored with resin composites or crowns and to identify potential risk factors, using a retrospective cohort design. MATERIALS AND METHODS: Dental records of molar ETT with crowns or composite restorations (recall period, 2015-2019) were collected based on inclusion and exclusion criteria. The incidence of unrestorable fractures was identified, and molar ETT were classified according to survival. Information on potential risk factors was collected. Survival rates and potential risk factors were analyzed using the Kaplan-Meier log-rank test and Cox regression model. RESULTS: The overall survival rate of molar ETT was 87% (mean recall period, 31.73 ± 17.56 months). The survival rates of molar ETT restored with composites and crowns were 81.6% and 92.7%, reflecting a significant difference (p < 0.05). However, ETT restored with composites showed a 100% survival rate if only 1 surface was lost, which was comparable to the survival rate of ETT with crowns. The survival rates of ETT with composites and crowns were significantly different (97.6% vs. 83.7%) in the short-term (12-24 months), but not in the long-term (> 24 months) (87.8% vs. 79.5%). CONCLUSIONS: The survival rate from fracture was higher for molar ETT restored with crowns was higher than for ETT restored with composites, especially in the first 2 years after restoration. Molar ETT with limited tooth structure loss only on the occlusal surface could be successfully restored with composite restorations.

Prevalence and morphology of multiple roots, root canals and C-shaped canals in mandibular premolars from cone-beam computed tomography images in a Thai population.

BACKGROUND/PURPOSE: Variations in root and root canal morphology of mandibular premolars of Thais has not been reported, and understanding these variations enhances endodontic success. The purpose was to investigate prevalence and morphology of multiple roots, root canals and C-shaped canals in mandibular premolars in a Thai population from cone-bean computed tomography (CBCT) images. MATERIALS AND METHODS: A total of 349 first mandibular premolars and 416 second premolars from CBCT images with 0.125-mm voxel size and 60 × 60 mm field of view were evaluated. Number of roots, root canals, and C-shaped canals were recorded and statistically analyzed using chi-square test. Root canal configurations were defined according to the Vertucci's classification. Levels and distances of separated multiple canals were reported. RESULTS: Multiple roots in mandibular first premolars were found at 5.73% while none of second premolars had. Multiple root canals were found in the first premolars at 19.48% and the second premolars at 3.85%. C-shaped canals (C1/C2) were found in the first premolars at 3.72% and the second premolars at 0.48%. All parameters in the first premolars were significantly higher than in the second premolars (p < 0.01). The majority of multiple root canals were defined as Vertucci's type V (1-2 canals). Multiple root canals were frequently separated at the middle level of roots about 6.5-7.0 mm from the cementoenamel junction. CONCLUSION: Prevalence of multiple roots/root canals and C-shaped canals in mandibular first premolars were significantly higher than in mandibular second premolars. Level of separation in multiple root canals was frequently at the mid-root level.

Survival Rates of Unrestorable Fracture of Endodontically Treated Anterior Teeth Restored with Resin Composites or Crowns: A Retrospective Cohort Study.

Introduction: Current guidelines for the restoration of endodontically treated anterior teeth (ETT) are based on laboratory results and insufficient clinical findings. This retrospective cohort study aimed to compare the survival rates of ETT with unrestorable fracture restored with direct resin composite (DRC) or full coverage crown (FCC), and identify predisposing factors. Methods and Materials: Dental records and radiographs of ETT restored with DRC or FCC were collected from the dental charts of patients who received endodontic treatments and attended recall(s) from 2007 to 2019. Clinical/radiographic data and incidence of unrestorable fracture were recorded. Survival rates of ETT with unrestorable fracture treated with DRC and FCC were analyzed using Kaplan-Meier survival analysis and log-rank test, whereas predisposing factors were identified using Cox proportional-hazard model. Moreover, the survival rates of maxillary ETT with different sites of remaining cervical tooth structure were analyzed. Results: A total of 263 ETT with 157 DRC and 106 FCC were recruited. At an average recall period of 38 months, the survival rate of ETT restored with FCC was significantly higher (99.1%) than DRC (90.4%) (P<0.05). The predisposing factors of ETT with FCC were not identified; however, the identified predisposing factors of ETT with DRC were: (i) considered less than three walls of remaining cervical tooth structure, (ii) the ratio between root dentin thickness and root canal width at the cervical region was less than 1:1:1, (iii) loss of posterior-teeth support, and (iv) parafunctional habits. Maxillary ETT with complete or palatal structure had a significantly higher survival rate than those without the palatal structure (P<0.05). Conclusion: Based on the findings of the current cohort study, the survival rate of ETT with unrestorable fracture restored with FCC was significantly higher than DRC. However, ETT without predisposing factors were not susceptible to fracture and could be successfully restored with DRC.

Flexural strengths and porosities of coated or uncoated, high powder-liquid and resin-modified glass ionomer cements.

BACKGROUND/PURPOSE: No study has previously investigated and compared whether resin coating could prevent the effect of dehydration on flexural strengths and porosities of high powder-liquid and resin-modified glass ionomer cements (HPL-GIC and RM-GIC). The purpose of this study is to investigate the effect of resin coating on flexural strengths and porosities of HPL-GIC and RM-GIC under a dry condition. MATERIALS AND METHODS: HPL-GIC (Equia Forte Fil) or RM-GIC (Fuji II LC) was mixed and loaded into a mold to create a bar-shaped specimen, n = 12 of each. The specimens were randomly divided into two groups, coated and uncoated, n = 6 of each. In the coated group, a resin coating agent (Equia Forte Coat) was applied and light cured for 20 s. After 72 h, each specimen was dried and scanned to detect porosities (% volume) using micro-computed tomography. After scanning, flexural strength (MPa) of the specimen was tested using a three-point bending method. RESULTS: Porosities of HPL-GIC were significantly higher than RM-GIC, either coated or uncoated group (p < .05). Flexural strengths of coated and uncoated HPL-GIC were 41.47 ±â€¯0.89 and 15.32 ±â€¯1.15 MPa that were significantly lower than those of RM-GIC at 104.77 ±â€¯3.97 and 52.90 ±â€¯2.17 MPa (p < .05). Flexural strengths of coated GICs were significantly higher than uncoated GICs (p < .05). CONCLUSION: Resin coating increased flexural strengths of GICs under dry condition. HPL-GIC had higher porosities and lower flexural strength than RM- GIC.

Shear bond strengths of calcium silicate-based sealer to dentin and calcium silicate-impregnated gutta-percha.

AIM: To compare the shear bond strengths of a calcium silicate-based root canal sealer (CSS), to dentin or calcium silicate-impregnated gutta-percha (CSGP), with the shear bond strengths of an epoxy resin-based sealer. METHODS: For sealer/dentin testing, 40 hemisectioned roots were divided into 2 groups. Coronal root dentin discs were bonded with CSS or epoxy resin-based sealer. For sealer/core material testing, CSGP and conventional gutta-percha discs were bonded with a matching sealer (N = 20 per group). The shear bond strengths were tested using a universal testing machine. The failed modes were analyzed using stereomicroscopy and scanning electron microscopy. RESULTS: The CSS sealer had significantly higher shear bond strength to dentin than did epoxy resin-based sealer (P < .01). However, shear bond strengths of the 2 sealers to core materials did not significantly differ (P = .74). The remnants of the CSS sealer adhering to dentin or calcium silicate gutta-percha disc were observed. CONCLUSIONS: The CSS sealer had better adhesion to dentin than did epoxy resin-based sealer. However, the bond of the CSS sealer to impregnated gutta-percha was not superior to the epoxy resin-based sealer bonded to conventional gutta-percha.

Fracture resistance, gap and void formation in root-filled mandibular molars restored with bulk-fill resin composites and glass-ionomer cement base.

AIM: To evaluate fracture resistance and gap/void presence of root-filled mandibular molars restored with 2 bulk-fill and 1 conventional resin composites, with or without a glass-ionomer cement (GIC) base. METHODS: Coronal access and mesio-occlusal (MO) cavities were prepared, then root canal treatment was performed on 30 mol/L. The teeth were randomly divided, according to the cavity volume, into 6 experimental groups (N = 5) and restored with conventional/light-cured (Ceram-X), bulk-fill/light-cured (SureFil SDR) or bulk-fill/dual-cured (Core-X Flow) with/without a 2-mm thick GIC base. Gaps and voids (%) were determined using microcomputed tomography. Intact teeth and unrestored teeth were used as negative and positive controls. Fracture load (N) was determined using a universal testing machine. RESULTS: No significant difference in fracture resistance or gap/void formation was found among the 3 resin composites. GIC-base groups revealed significantly lower fracture strength than intact teeth, while fracture strengths of no GIC-base groups were not significantly different from intact teeth. GIC-base groups revealed significantly more gaps and voids in the area of the GIC than the resin composite. CONCLUSION: Conventional and bulk-fill resin composites provided similar fracture resistance and gaps/voids in root-filled molars with MO cavities. Placing a GIC base decreased fracture resistance and increased gap/void formation.

Comparison of the Effects of Intraradicular Materials on the Incidence of Fatal Root Fracture in Immature Teeth Treated with Mineral Trioxide Aggregate Apexification: A Retrospective Study.

INTRODUCTION: This study aimed to compare the incidence of root fractures that led to extraction in immature teeth endodontically treated by mineral trioxide aggregate (MTA) apexification and were restored with either reinforced (resin composite or fiber post) or nonreinforced (gutta percha or MTA) intraradicular materials. METHODS: Necrotic immature teeth treated with MTA apexification from 1996 to 2017 were selected according to the inclusion and exclusion criteria. Intraradicular materials and preoperative and treatment factors were obtained from dental charts and radiographs. The incidence of fatal root facture was identified. Kaplan-Meier survival analysis and the Cox proportional hazard model were used to show the survival rate and predisposing factors at a significance level of .05. RESULTS: The average recall period was 30 months. The incidence of root fracture in the teeth restored with the reinforced materials was 5.5%, which was not significantly different from the nonreinforced materials (8.3%). Furthermore, the fracture rates between the fiber post and resin composite groups were not significantly different. Two significant predisposing factors influencing the incidence of root fracture were detected: preoperative external inflammatory root resorption (hazard ratio = 26.86; P < .05) and patient age > 15 years (hazard ratio = 8.60, P < .05). CONCLUSIONS: Immature teeth treated with MTA apexification and restored with the reinforced or nonreinforced intraradicular materials exhibited a similar rate of root fracture. Preoperative external inflammatory root resorption and patient age > 15 years were found to be the predisposing factors that significantly increased the incidence of root fracture.

Endodontically treated posterior teeth restored with or without crown restorations: A 5-year retrospective study of survival rates from fracture.

AIM: The aim of the present study was to investigate survival rates from fracture of endodontically treated posterior teeth (ETT) restored with or without crowns with recall periods of up to 5 years. METHODS: ETT with single-unit crown or resin composite restorations were studied based on the inclusion criteria. Restoration, tooth structure loss, adjacent teeth, fracture, and restorability were recorded. Survival rates from fracture were calculated, and risk factors were identified. RESULTS: Overall, survival rate of ETT with crowns (92.2%) was significantly higher than resin composites (77.4%) (P < 0.05). ETT with one or two surface loss/es and two adjacent teeth had a high survival rate of 86.9%, which was not significantly different to ETT with crowns (P ≥ 0.05). Restoration and adjacent teeth were identified as significant factors. The majority of fractured ETT with resin composites were restorable, whereas those with crowns were unrestorable. Survival rates from unrestorable fracture were not significantly different between the crown (93.1%) and resin composite (96%) (P ≥ 0.05). CONCLUSIONS: The survival rate from the fracture of ETT restored with crowns was significantly higher than ETT restored with resin composites, but was not significantly different to ETT with one or two ETT with one or two surface loss/es and two adjacent teeth. ETT restored with resin composites had mostly restorable fracture, whereas ETT with unrestorable fracture were similar between the two restorations.

Pulpal responses after direct pulp capping with two calcium-silicate cements in a rat model.

Bioactivity of Bio-MA, a calcium chloride accerelator-containing calcium-silicate cement, as a pulp capping material was evaluated on mechanically exposed rat molar pulp. Sixty maxillary first molars from Wistar rats were mechanically exposed and assigned to two capping materials: Bio-MA or white mineral trioxide aggregate (WMTA), and three periods: 1, 7, or 30 days. Nine molars were exposed and covered with polytetrafluoroethylene tape, as positive controls. From histological examination, inflammatory cell infiltration and reparative dentin formation were evaluated using grading scores. No significant difference in pulpal responses between the two materials was observed at any period (p>0.05). At 1 day, all experimental groups showed localized mild inflammation. At 7 days, dentin bridge was partially observed at exposure sites with few inflammatory cells. At 30 days, pulp appeared normal with complete tubular dentin bridges. Bio-MA with accerelator was biocompatible similar to WMTA and could be used as a pulp-capping material.

Root Reinforcement after Obturation with Calcium Silicate-based Sealer and Modified Gutta-percha Cone.

INTRODUCTION: A root canal obturated with a calcium silicate-based sealer (bioceramic sealer [BCS]) and a modified gutta-percha cone (bioceramic cone [BCC]) might improve the fracture resistance of the root. The objective of this study was to evaluate root reinforcement of a bioceramic cone/sealer (TotalFill; FKG Dentaire SA, La Chaux-de-Fonds, Switzerland) by investigating the fracture resistance, push-out bond strength, sealer penetration, and modulus of elasticity (MOE) in comparison with gutta-percha/AH Plus (Dentsply Maillefer, Tulsa, OK) (GP/AH). METHODS: Eighty-four roots from bilateral mandibular premolars were prepared. For fracture resistance, 40 teeth were randomly divided into 4 groups (n = 10 each): intact roots (negative control), prepared roots (positive control), and the roots obturated with either BCC/BCS or GP/AH. Root canals were obturated with the matched single-cone technique and vertically loaded with a spreaderlike tip until fracture. For push-out bond strength (n = 10 each), coronal, middle, and apical root slices of BCC/BCS and GP/AH were loaded with a cylindrical plunger, and failure modes were determined. Sealer penetration of BCC/BCS and GP/AH (n = 12 each) was evaluated for the maximum depth and the circumferential and total area of penetration at the coronal, middle, and apical levels using confocal laser scanning microscopy. The MOE was investigated according to ISO 4049:2000. RESULTS: The fracture load of BCC/BCS, GP/AH, and the intact roots was not significantly different but significantly higher than the prepared, nonobturated roots. BCC/BCS provided a higher bond strength, maximum depth, and circumferential penetration at the apical root level as well as a greater sealer penetration area at all levels compared with GP/AH. The MOE of all materials was much lower than dentin. CONCLUSIONS: BCC/BCS and GP/AH bonded and reinforced the prepared roots; their fracture resistances were similar to the intact roots.