Restoration of Teeth with Severely Compromised Tooth Structure using Digital Planning Combined with Orthodontic Magnetic Extrusion-A Report of 2 Cases.

This report outlines 2 digitally planned cases in which the teeth underwent magnetic extrusion to preserve the supracrestal tissue attachment and regain the ferrule, followed by their restoration. Case 1: A 42-year-old man with the chief concern of a fractured right maxillary second premolar. Following the completion of root canal treatment, the remaining tooth structure was insufficient to create a ferrule for tooth restoration. For this scenario, a rapid magnetic extrusion technique was performed on tooth #4 to obtain an approximate 3-mm ferrule. The condition of both the dentition and the restorative margin was acceptable 18 months following treatment. Case 2: A 62-year-old man with the chief complaint of mobility on both sides of the maxillary arch in relation to a tooth-supported fixed partial denture (FPD). Following removal of the FPD, multiple extractions were carried out and tooth #6 was subjected to magnetic extrusion in 3 stages to a maximum of 4 mm to obtain a ferrule. At the 18-month and 3-year follow-up appointments, the tooth had no symptoms and the gingiva around the restorations had optimal architecture and margins. The 3-dimensional digital planning was helpful in precisely positioning the magnets within the tooth and the provisional restorations to facilitate axial extrusion. The extruded teeth were restored with zirconia crowns in both cases. The beneficial outcomes observed from these cases provides evidence that the integration of digital planning and magnetic extrusion holds promise as a method for reconstructing teeth with crowns that are significantly compromised.

Influence of Cementation Mode and Ferrule Design on the Fatigue Resistance of Monolithic Zirconia Endocrowns.

Background: Classic endocrowns made of dental ceramics are considered a promising alternative to traditional post-endodontic restorations. The use of circular ferrules in endocrowns is a topic of controversial discussion. Therefore, the present study aims to evaluate the effect of ferrule design and cementation mode on the fatigue resistance of zirconia endocrowns. Methods: Eighty human molars were divided into four groups (n = 20): NFC (no-ferrule, conventional cementation), NFA (no-ferrule, adhesive luting), FC (ferrule, conventional cementation) and FA (ferrule, adhesive luting). Both the classic and the modified endocrown preparation with a two-millimeter ferrule design were carried out. Endocrowns were fabricated from zirconia using the CEREC system. After thermocycling, specimens were loaded according to the step-stress test up to 1500 N. Results: Failure rate was low; 88.8% of total specimens passed the step-stress test. Fractures were distributed between all groups; no significant differences in fatigue resistance were detected for preparation design and cementation mode. Conclusions: Endocrowns appear to be a promising concept for endodontically treated molars. Ferrule and also cementation mode have only a minor influence on fatigue resistance of zirconia endocrowns. However, at very high forces, the marginal area of the ferrule represents a weak point.

Structurally compromised teeth. Part I: Clinical considerations and novel classification proposal.

OBJECTIVE: A comprehensive classification of structurally compromised teeth (SCT) was introduced. CLINICAL CONSIDERATIONS: Dental injuries or operative mismanagement undermine the structural integrity of the tooth abutment, reducing its biomechanical strength and rendering restorative procedures challenging. To standardize the overall pre-operative evaluations and determine the biological and mechanical features, a classification of the coronal and cervical tooth defects, as well as an attentive analysis of the most apical location of the residual cervical tooth structure along the whole perimeter and the most coronal location of the bucco/lingual residual structure was presented. Considering the residual cervical structure, five possible clinical scenarios were individuated with respect to the gingival margin, gingival sulcus, supracrestal tissue attachment and bone crest (BC). The latter prevents the isolation procedures rendering the adhesive restorations unfeasible. Instead, the location of the most apical portion of residual cervical structure within subgingival/intrasulcular depth (>1.5 mm above BC) can be considered restorable. CONCLUSIONS: This classification is threefold: to enclose all the possible clinically encountered tooth defects, to identify the apical problems of SCT to appropriately manage the perio-restorative interfaces, and to evaluate the tooth resistance capacity of SCT, as to plan and perform the most adequate biomechanical restorative approach. CLINICAL SIGNIFICANCE: The present classification is proposed to provide a complete perspective of structurally compromised teeth to standardize the biologic and biomechanical evaluations during planning of restorative procedures.

Retrospective Assessment of Endodontically Treated Teeth Replaced by Dental Implants.

INTRODUCTION: This study investigated endodontically treated teeth that were replaced by dental implants at the University of North Carolina (UNC) at Chapel Hill School of Dentistry. The primary objective of this study was to determine the reasons leading to the extraction of endodontically treated teeth and their subsequent replacement with dental implants. The secondary objective was to evaluate the proportion of these teeth that, according to experienced endodontists, could have been preserved. METHODS: The UNC-Chapel Hill's dental electronic health records between 2004 and 2019 were probed for implant placement that replaced root canal-treated teeth. Preextraction radiographs and clinical charts were examined to ascertain the primary reason related to the extraction and to compile a profile for each case. In cases in which endodontic failure was the primary reason for extraction, radiographs and clinical findings were evaluated by 2experienced endodontists to assess potential treatment options. RESULTS: Between 2004 and 2019, 29.3% (1564 of 5229) of teeth replaced by dental implants at UNC School of Dentistry had undergone root canal treatment, with the mandibular first molar being the most commonly replaced tooth. The leading reasons for extraction were recurrent caries associated with defective restoration (26.6%), fracture of coronal structure (21.5%), vertical root fracture (20.9%), compromised periodontal condition (13.8%), and endodontic failure (2.4%). Two experienced endodontists evaluated extractions due to endodontic failure and concluded that 61.7% of them could have been candidates for endodontic retreatment. CONCLUSION: Substantial loss of tooth structure was the leading cause of extraction of root canal-treated teeth, followed by vertical root fracture and periodontal disease. Although endodontic failure constituted a minor portion of the reasons for extraction, a considerable number of teeth were extracted due to vertical root fractures following root canal treatment. A significant proportion of the extracted teeth due to endodontic failure could have been considered as potential candidates for endodontic retreatment.

A 65-Year-Old Man with Recent History of Radiation Therapy to the Head and Neck Reporting for Treatment of a Non-restorable Tooth.

Patients with a history of head and neck radiation involving or adjacent to tooth-bearing areas are at increased risk of developing osteonecrosis following dental procedures. The dental provider should thus aim to preserve the patient's dentition after radiation therapy. Root canal therapy with coronectomy may be an option for a nonrestorable tooth, whereas atraumatic extraction can be considered if retaining the tooth is impossible. When treating a patient with a history of head and neck radiation, it is recommended that the dental provider reviews the patient's radiation records and consults with the patient's radiation oncologist to better stratify treatment risks.

The effect of different ferrule heights and crown-to-root ratios on fracture resistance of endodontically-treated mandibular premolars restored with fiber post or cast metal post system: an in vitro study.

BACKGROUND: This study aimed to investigate the effects of different ferrule heights and crown-to-root ratios on the fracture resistance of endodontically-treated premolars restored with fiber post or cast metal post system. METHODS: Eighty extracted human mandibular first premolars with single root canal were treated endodontically and cut from 2.0 mm above the buccal cemento-enamel junction, to create horizontal residual roots. The roots were randomly divided into two groups. The roots in group FP were restored with a fiber post-and-core system, while the roots in group MP were restored with a cast metal post-and-core system. Each group was divided into five subgroups with different ferrule heights (0: no ferrule; 1: 1.0 mm ferrule; 2: 2.0 mm ferrule; 3: 3.0 mm ferrule; 4: 4.0 mm ferrule). All specimens were subsequently restored with metal crowns and embedded in acrylic resin blocks. The crown-to-root ratios of the specimens were controlled at approximately 0.6, 0.8, 0.9, 1.1, and 1.3 of the five subgroups, respectively. Fracture strengths and fracture patterns of the specimens were tested and recorded by a universal mechanical machine. RESULTS: Mean fracture strengths (mean ± standard deviation (kN)) of FP/0 to FP/4 and MP/0 to MP/4 were: 0.54 ± 0.09, 1.03 ± 0.11, 1.06 ± 0.17, 0.85 ± 0.11; 0.57 ± 0.10, 0.55 ± 0.09, 0.88 ± 0.13, 1.08 ± 0.17, 1.05 ± 0.18 and 0.49 ± 0.09, respectively. Two-way ANOVA revealed significant effects of different ferrule heights and crown-to-root ratios on the fracture resistance (P < 0.001), but no difference in fracture resistance between two post-and-core systems (P = 0.973). The highest fracture strengths of the specimen were found with the ferrule length of 1.92 mm in group FP and 2.07 mm in group MP, the crown-to-root ratio of which in 0.90 and 0.92 respectively., there is a significant difference in fracture patterns among the groups(P < 0.05). CONCLUSIONS: When a certain height of ferrule is prepared and a cast metal or fiber post-and-core system is restored for the residual root, the clinical crown-to-root ratio of the tooth after restoration should be kept within 0.90 to 0.92, so as to improve the fracture resistance of endodontically-treated mandibular first premolars.

Forced surgical extrusion using an axial tooth extraction system as a practicable technique for preserving severely destroyed teeth? - Clinical outcomes up to 4.8 years.

OBJECTIVE: Several extrusion techniques have been described to restore teeth with insufficient coronal tooth structure and to avoid their extraction. Still, there is little evidence for a treatment concept combining surgical extrusion using an atraumatic axial extraction system. MATERIALS AND METHODS: A total of nine patients, each with an iso- or subgingival fractured tooth, were retrospectively examined. Treatment of the damaged tooth comprised an atraumatic forced surgical extrusion performed with an axial tooth extraction system and a more coronal positioning within the socket. The teeth were initially splinted and subsequently restored. The follow-up period was up to 57.1 months and averaged 36.5 (SD: ±13.5) months. RESULTS: All nine teeth were still in situ, without signs of inflammation. During the period of the provisional restoration, six prosthetic complications occurred, which were resolved with little effort, whereas, success rate for the definitive restoration was 100%. No biological complications were observed concerning the root apex or soft tissue. The radiographically measured mean extrusion distance was 3.4 (SD: ±1.0) mm, so that a sufficient prosthetic ferrule could be reestablished. CONCLUSIONS: Surgical extrusions using an axial tooth extraction system demonstrate low biological and prosthetic complications rates over observation time. CLINICAL SIGNIFICANCE: The presented extrusion approach preserves soft and hard tissue and is an efficient treatment option for severely destroyed teeth. Saving hopeless teeth by this relatively predictable and feasible procedure has hardly any disadvantages for patients, and in case of failure, an implant or fixed partial denture are still an option.

Crosslinking of Bovine Gelatin Gels by Genipin Revisited Using Ferrule-Top Micro-Indentation.

(1) Background: Gelatin is widely used in food science, bioengineering, and as a sealant. However, for most of those applications, the mechanical properties of gelatin gels need to be improved by means of physical or chemical crosslinking. Among the used chemical agents, genipin allows low cytotoxicity in addition to improved Young's modulus. However, the mechanical properties of gelatin-genipin gels have only been investigated at the macroscale, and there is no knowledge of the influence of the genipin concentration on the surface homogeneity of Young's modulus. (2) Methods: To this aim, the influence of genipin concentration on Young's modulus of gelatin gels was investigated by means of ferrule-top micro-indentation. The data were compared with storage moduli obtained by shear rheology data. (3) Results: Ferrule-top indentation measurements allowed us to show that Young's moduli of gelatin-genipin gels increase up to a plateau value after approximately 12 mg/mL in genipin and 4 h of crosslinking. Young's moduli distribute with high homogeneity over 80 µm × 80 µm surface areas and are consistent with the storage moduli obtained by shear rheology. (4) Conclusions: It has been shown that ferrule-top indentation data fitted with the Hertz model yield Young's moduli of gelatin-genipin gels which are consistent with the storage moduli obtained by characterization at the macroscale using shear rheometry. In addition, Young's moduli are homogenously distributed (with some irregularities at the highest genipin concentrations) and can be increased by two orders of magnitude with respect to the uncrosslinked gel.

Effect of partial ferrule on fracture resistance of endodontically treated teeth: A meta-analysis of in-vitro studies.

PURPOSE: The present meta-analysis aimed to answer the following research question: In endodontically treated teeth (ETT), what is the effect of partial ferrule (PF) on fracture resistance compared to complete ferrule (CF) and/or no ferrule (NF)? STUDY SELECTION: PubMed, Scopus, Web of Science, and Google Scholar were searched for relevant studies published until May 20, 2022. In vitro studies that compared the effect of partial ferrule with that of complete ferrule and/or no ferrule on fracture resistance of ETT were included. The studies were assessed for risk of bias, and a meta-analysis was performed. RESULTS: Seventeen in vitro studies comprising 807 teeth were included. Nine studies were at a high risk of bias and eight presented a moderate risk of bias. Overall, the results showed that CF was superior to PF in increasing fracture resistance (SMD= 0.93, CI95%= 0.57-1.29, P< 0.0001), with no change in the effect based on the type of teeth (P< 0.001). However, the subgroup analysis found that PF 2 mm buccal, lingual, and buccal and lingual ferrule were comparable to CF (P= 0.06). Additionally, the PF group showed significantly higher fracture resistance than the NF group (SMD= 2.02, CI95%= 1.54-2.49, P< 0.00001). CONCLUSIONS: Although CF design provided the highest fracture resistance to restored ETT, PF can still be a viable option for restoring ETT in cases where CF is not feasible.

Influence of presence or absence of posts on the failure rates of post endodontic restorations: A systematic review and meta-analysis.

Aim: The study was designed to evaluate the existing evidence on the failure rates of post-endodontic restorations retained with and without post in endodontically treated teeth (ETT). Settings and Design: Preferred Reporting Items for Systematic Reviews and Meta-Analyses- Protocol (PRISMA-P) guidelines were used to formulate the review. Materials and Methods: Randomized controlled trials (RCT's) and prospective clinical studies comparing post endodontic restorations retained with and without post were included. PubMed/Medline, Embase, Cochrane Library and Scopus databases were searched to recognize relevant full-text articles in English language. The quality of the RCT's were evaluated using the Cochrane collaboration tool to assess the risk of bias and reported as having high, low or unclear risk. Random-effects model at a 95% confidence interval was used for the meta-analysis. Statistical Analysis Used: Meta-analyses was performed using the Mantel -Haenszel method31 and risk ratio, with a 95% confidence interval (CI), was estimated for dichotomous data. Random effects model32 was used as the pooling method and 95% confident interval (α = .05 for RR values) in Review Manager (RevMan) [Computer program]. Version 5.4. The Cochrane Collaboration, 2020). Results: Four studies comparing post retained and post free restorations in ETT with a total of 916 restorations were included in the analysis. The total risk ratio was 2.16, (95% CI:1.25 to 3.72). Conclusion: ETT with post retained restorations exhibited significantly lower failure rates compared to restorations without post. Well-designed RCT's are warranted to develop a clinical protocol with respect to post-retained restorations.

Ferrule effect and its importance in restorative dentistry: A literature Review.

This review aims to report the current literature on the status of ferrule in root-filled teeth, classify the different types of ferrules, highlight the biomechanical failures due to inadequate ferrule effect, and discuss the current restorative concepts according to the ferrule design principles.

Rehabilitación de dientes con pronóstico imposible mediante extrusión quirúrgica: a propósito de un caso / Surgical extrusion for restoring impossible prognosis teeth: case report

La extrusión quirúrgica es una alternativa terapéutica que persigue el desplazamiento coronal de aquellos dientes con márgenes subgingivales y limitada estructura remanente. El correcto diag nóstico de cada caso y la aplicación de una técnica mínimamente traumática serán clave en el éxito del tratamiento. En la presente revisión, a propósito de un caso con 12 meses de seguimiento, se analizan los factores críticos del procedi miento (AU)

Surgical extrusion is a therapeutic alternative that pursues the coronal displacement of those teeth with subgingival margins and limited remaining structure. The correct diagnosis of each case and the application of a minimally traumatic technique will be key to the success of the treatment. In this review, about a case with 12 months of follow-up, the critical factors of the procedure are analyzed (AU)

Effect of surface treatment, ferrule height, and luting agent type on pull-out bond strength of monolithic zirconia endocrowns.

PURPOSE: To evaluate the effect of different surface treatments, ferrule heights, and luting agents on the pull-out bond strength (PBS) of computer-aided design/computer-aided manufacturing (CAD-CAM) monolithic endocrowns. METHODS: After endodontic treatment and preparation for two endocrown designs (ferrule height 0 mm or 2 mm), CAD-CAM monolithic zirconia endocrowns were fabricated for 80 mandibular molars. Each endocrown design group was then divided on the basis of surface treatment into two groups: half were air-abraded and half were air-abraded/laser-irradiated. Then, all treated groups were further divided into two subgroups (n = 10) and cemented to teeth with either a 10-methacryloyloxydecyl dihydrogen phosphate (MDP)-containing resin luting agent (Panavia SA) or a combination of MDP-containing primer and MDP-free resin luting agent (Monobond Plus/Multilink Automix). PBS was measured with a universal test machine after simulated chewing and thermocycling. Three-way ANOVA and the post-hoc Bonferroni test were used for statistical analysis. RESULTS: PBS was significantly associated with type of surface treatment, type of luting agent, and ferrule height. Air-abraded/laser-irradiated endocrowns with a 2-mm ferrule that were cemented with Monobond Plus/Multilink Automix had the highest PBS (P < 0.05). CONCLUSION: Surface treatment with air abrasion/laser irradiation, presence of a ferrule, and priming with an MDP-containing primer increased the PBS of monolithic zirconia endocrowns.

Prosthetic restoration after atraumatic surgical extrusion: a report of two cases.

Preservation and restoration of teeth with little coronal tooth structure due to crown-root fractures or caries lesions, ensuring restoration margins do not encroach on the biologic width, constitute a challenge. Available treatment options include surgical crown lengthening and orthodontic or surgical extrusion. This report presents two patients in which teeth were restored by surgical extrusion with an atraumatic extraction system and prosthetic therapy.

Physical and Numerical Simulations on Mechanical Properties of a Prefabricated Underground Utility Tunnel.

The "U-shaped ferrule joint bars connections" have a stable mechanical property, requiring a low level of construction accuracy and a relatively simple connection process, which significantly increase the construction speed. Based on the "U-shaped ferrule joint bars connections" technology, a new type of prefabricated concrete underground utility tunnel was proposed. This prefabricated technology realizes a formwork-free construction and vertical support-free assembly of the top plate on site. Through the full-scale model static test and numerical analyses, the mechanical properties, i.e., the crack development law and bearing capacity, were systematically investigated to validate the effectiveness of the "U-shaped ferrule joint bars connections". The test results indicated that the performance of the "U-shaped ferrule joint bars connections" is reliable. During the loading process, the prefabricated utility tunnel experienced three stages, i.e., cracking, stiffness degradation, and ultimate failure. The numerical analysis results correlated with the test results well. The simulation results showed that the bearing capacities of the prefabricated underground utility tunnel and the cast-in-place utility tunnel were similar. The longitudinal joint connections of the prefabricated utility tunnel allow the structure as an integration to maintain favourable mechanical properties.

Effect of bone defect width and a ferrule on the fracture characteristics of vertically fractured teeth reattached with adhesive resin cement: An in vitro study.

This study aimed to clarify the effects of vertical bone defect width and a ferrule on fracture of the fragments of fractured tooth reattached with adhesive resin cement (reattached tooth). The reattached tooth was built up by a fiber post and composite resin core for abutment and formed to the abutment with or without a ferrule. The vertical bone defect was fabricated with a V-shaped defect in different widths. The fracture load was evaluated using a universal testing machine. The vertical bone defect did not affect the fracture load, but a ferrule increased the root fracture load. For the specimens without a ferrule, debonding between the composite resin core and the root at the coronal loading side and fractures at the apical side of the root were found. In conclusion, the ferrule at abutment could affect fracture load and modes, and the bone defect width did not.

Fracture Resistance in Non-Vital Teeth: Absence of Interproximal Ferrule and Influence of Preparation Depth in CAD/CAM Endocrown Overlays-An In Vitro Study.

There is ample evidence to support the use of endocrowns to restore endodontic teeth. However, the influence of the position of the interproximal margins on fracture strength has not yet been studied. The aim was to determine the relationship between the apicocoronal position of the interproximal restorative margins and fracture resistance in nonvital teeth restored with CAD/CAM endocrown overlays. Forty extracted human maxillary premolars were prepared for endocrown overlay restorations without ferrule on the interproximal aspects and classified according to the position of the interproximal restoration margins in relation to the alveolar crest: 2 mm (group A), 1 mm (group B), 0.5 mm (group C), and 0 mm (group D). Fracture strength was measured using a universal testing machine applying a compressive force to the longitudinal tooth axis. Group A had a mean fracture resistance of 859.61 (±267.951) N, group B 1053.9 (±333.985) N, group C 1124.6 (±291.172) N, and group D 780.67 (±183.269) N, with statistical differences between groups. Group C had the highest values for fracture strength compared to the other groups (p < 0.05). The location of the interproximal margins appears to influence the fracture resistance of CAD/CAM endocrown overlays. A distance of 0.5 mm between the interproximal margin and the alveolar crest was associated with increased fracture resistance.

Fracture resistance of thin wall endodontically treated teeth without ferrules restored with various techniques.

OBJECTIVE: To evaluate the fracture resistance and failure characteristics of simulated thin wall endodontically treated teeth without ferrules restored with various techniques. MATERIALS AND METHODS: Forty-eight human mandibular single-root canal premolars were decoronated and endodontically treated. The 1 mm thick remaining root canal dentin was prepared. The roots were randomly divided into four groups of 12 roots according to the following post and core reconstruction techniques: direct resin composite post and core (CP), multiple fiber posts and resin composite core (FP), CAD/CAM anatomical post and core (AP), and metal cast post and core (MP). Full metal crowns were cemented to the cores. All specimens were subjected to thermocycling for 5000 cycles and submitted to axial compression until failure at a 45°angle using a universal testing machine. The failures were classified into one of the followings: post and/or core fractures, root fractures, and root fractures combined with post and/or core fractures. RESULTS: Average failure loads of groups CP, FP, AP, and MP were 360.0, 655.2, 402.7, and 856.1 N, respectively. MP provided the highest failure load, which was significantly higher than those of the other groups (p < 0.05). FP was second, being inferior to MP with a significance level of p = 0.039. CP exhibited the least failure load, and it was not significantly different from the AP group (p > 0.05). Root fractures were the major failure mode for most of the specimens except the CP group, in which composite fractures at the cervical level were commonly observed. CONCLUSION: Metal cast post and core provided the highest fracture resistance for reconstruction of a thin wall in endodontically treated teeth without ferrules, followed by multiple fiber posts and resin composite core. The milled anatomical post and core and a direct resin composite post and core provided significantly lower fracture resistance. CLINICAL SIGNIFICANCE: Metal cast posts and core and multiple fiber posts with resin composite core techniques were effective for restoring severely compromised endodontically treated teeth.

Periodontal and Periapical Outcomes of Surgical Extrusion: A Prospective Clinical Volumetric Study.

INTRODUCTION: Outcome predictors for the restoration of endodontically treated teeth mainly include cavity wall integrity and the presence of a 1.5-2 mm ferrule. However, in some clinical situations, the aforementioned predictors cannot be achieved. Three different techniques have been proposed to obtain an adequate ferrule respecting the supracrestal tissue attachment: surgical crown lengthening, orthodontic forced eruption, and surgical extrusion. There are little published prospective data evaluating periodontal changes after surgical extrusion. Therefore, the aims of this study were to report the outcome of surgical extrusion in single-rooted teeth, to digitally evaluate soft tissue volumetric changes after surgical extrusion, and to observe patient satisfaction regarding the treatment after a minimum of 1 year. METHODS: This prospective clinical study was performed between 2017 and 2020. Thirteen patients referred for surgical extrusion met the following inclusion criteria: nonsmokers; systemically healthy with at least 1 straight, single-rooted tooth with an insufficient ferrule; a favorable tooth crown-to-root ratio, and no periodontal pathology. Preoperative clinical variables included patient age, sex and phenotype, tooth number, tooth mobility, crown-to-root ratio, gingival index (GI), probing pocket depths at 6 sites, bleeding on probing (BOP), and mesial and distal interproximal papillae volume. Surgical extrusion was performed by a single operator who completed the root canal treatment/retreatment and restored the teeth with a crown. One year later, all patients were controlled, and the following variables were recorded: tooth mobility, crown-to-root ratio, GI, pocket depth, BOP, interproximal papillae aspect, soft tissue rebound, periapical healing, marginal bone loss, and patient-reported outcome measures of the treatment. All variables were analyzed using a descriptive method (mean, %). The Wilcoxon test was used to evaluate pre- and postoperative clinical parameters at a significance level of .05. RESULTS: At a mean follow-up period of 18.8 months, no teeth were extracted. Compared with preoperative GI and BOP, a significant reduction was observed at 1 year after surgery. Likewise, no significant differences in probing depths were shown, and only 1 tooth presented a type 2 mobility. The mean soft tissue rebound was -0.46 ± 0.69 mm. Overall, no significant interproximal papillae height loss was observed.Apical lesions were completely healed after surgery. The tooth crown-to-root ratio was favorable in all cases before extrusion, whereas in 3 cases it was appropriate (1 = 1), and only 1 case presented >25% of marginal bone loss during the follow-up period. The reported success rate was 92.3%, and patients were generally satisfied with the outcome. CONCLUSIONS: Surgical extrusion of single-rooted teeth was successful with minimal or no soft tissue loss, and patients were satisfied with the surgical procedure and the esthetic result.

Influência da férula na resistência à fratura de restaurações com utilização ou não de retentores intrarradiculares em dentes tratados endodonticamente: uma revisão da literatura / Influence of the ferrule on the fracture resistance of restorations with or without the use of intraradicular posts in endodontically treated teeth: a literature review

Objetivo: realizar uma revisão de literatura narrativa sobre a importância e a influência do efeito férula na resistência à fratura de restaurações em dentes tratados endodonticamente com utilização ou não de retentores intrarradiculares. Metodologia: Foram utilizados os seguintes descritores indexados no DeCS (Descritores em Ciências da Saúde): "Férula", Prótese Dentária", "Falha da Restauração Dentária", "Técnica de Retentor Intrarradicular" e "Pinos de Retenção Dentária" para busca nas bases de dados PubMed, Embase, Lilacs, Web of Science, Scopus e Cochrane Library. Resultados: Os dados da maioria dos estudos in vitro ou in vivo incluídos nesta revisão sugerem o uso da férula para aumento da resistência à fratura e longevidade dos dentes tratados endodonticamente. Tem sido recomendada a confecção de uma férula com altura uniforme de 2 mm e espessura superior a 1,5 mm. Conclusão: O uso de retentores radiculares foi indicado pela maioria dos trabalhos, sendo geralmente recomendados os pinos de fibra de vidro ao invés de núcleos metálicos fundidos para minimizar os riscos de fratura radicular em razão do módulo de elasticidade semelhante à dentina, além de possibilidade de retratamentos em casos de falhas adesivas. Apesar disso, ainda são necessários estudos clínicos com acompanhamento a longo prazo para avaliar a longevidade das restaurações de dentes tratados endodonticamente utilizando pinos de fibra de vidro sem ou com a presença de férula em diferentes espessuras e alturas.

Objective: This study aimed to conduct a narrative literature review on the importance and influence of the ferrule effect on the fracture resistance of restorations in endodon-tically treated teeth with or without the use of intraradicular posts. Methodology: The following descriptors indexed in the DeCS (Health Sciences Descriptors) were used: "Ferrule", Dental Prosthesis", "Dental Restoration Failure", "Post and Core Technique", and "Dental Posts", to search on the databases of PubMed, Embase, Lilacs, Web of Science, Scopus, and Cochrane Library data. Results: Data from most of the in vitro or in vivo studies included in this review suggest the use of the ferrule to increase fracture resistance and longevity of endodontically treated teeth. It has been recommended to make a ferrule with a uniform height of 2 mm and a thickness greater than 1.5 mm. Conclusion: The use of intraradicular posts was indicated by most studies, and fiberglass posts are generally recommended instead of cast metal cores to minimize the risk of root fracture due to the modulus of elasticity similar to dentin, in addition to the possibility of retreatments in ad-hesive failure cases. Despite this, clinical studies with a long-term follow-up are essential to evaluating the longevity of restorations of endodontically treated teeth using fiberglass posts without or with the presence of ferrule in different thicknesses and heights.