Effects of minimally invasive endodontic access cavity in molar teeth on polymerization, porosity and fracture resistance.

Minimally invasive access cavities have been proposed in the last decade to reduce tooth tissue loss during endodontic treatment and mitigate compromised fracture resistance of endodontically treated teeth. Fracture resistance of molars with different types of access cavity design may be affected by restorative materials and aging. Insufficient literature data exist on the effect of cavity design and type of restorative materials on restorative aspects such as material adaptation or photo-polymerization in restricted access cavities. This study analyses quality of polymerization, material adaptation and fracture resistance of molars with different types of access cavities restored with glass-ionomer, high-viscosity fiber-reinforced bulk-fill and nanofilled resin composite. Plastic molar teeth with truss (TREC) and traditional endodontic access cavity (TEC) were restored with nanofilled composite (Filtek Supreme), glass-ionomer Fuji IX and Filtek or fiber-reinforced everX Posterior and Filtek. Porosity was determined using microcomputer tomography and the degree of conversion of resin-based materals using micro-Raman spectroscopy. Human molars prepared and restored in the same way were used for fracture resistance testing at baseline and after thermocycling. The results demonstrate that high-viscosity fiber-reinforced composite was difficult to adapt in TREC cavity leading to greater porosity than Filtek or Fuji. TREC design did not affect composite polymerization and led to higher fracture resistance of restored molars compared to TEC but also more unrestorable fractures.

Clinical application of Er:YAG laser and traditional dental turbine in caries removal in children.

This study compares the clinical efficacy of erbium-doped:yttrium-aluminium-garnet (Er:YAG) laser and traditional dental turbine in caries removal in children. The study cohort comprised 78 children aged 5 to 10 years with caries in two symmetrical maxillary molars. Different carious sides of the same child were randomly divided into control and observed sides. For each child, the caries on the control side were treated with a traditional dental turbine, while the observed side was treated with an Er:YAG laser. The study evaluated the use of anesthetics, pain levels, tooth hypersensitivity and the occurrence and severity of tooth fractures during caries removal with different methods. Additionally, the clinical anxiety and cooperative behavior of the children were observed. The time required for caries removal and cavity preparation by both methods was recorded, and the success rate of treatment was assessed after one year of follow-up. The results indicated a significant reduction in the use of anesthetics, pain and the incidence and severity of tooth hypersensitivity with the use of Er:YAG laser (p < 0.05). No significant difference was found in the occurrence of tooth fractures between the two groups (p > 0.05). The children treated with Er:YAG laser demonstrated better clinical anxiety levels and cooperative behavior. However, the time required for cavity preparation was longer with the use of Er:YAG laser (p < 0.05). After a 12-month follow-up, there was no significant difference in the success rate of treatment between the two groups (p > 0.05). In conclusion, compared to the traditional dental turbine, the use of Er:YAG laser improves treatment comfort and cooperation in children with caries and reduces the need for intraoperative anesthetics.

Effect of temperature on rehydration and fracture resistance of reattached tooth fragments after crown fracture: An in vitro study.

BACKGROUND: Uncomplicated crown fractures of maxillary anterior teeth are common dental injuries, and the bonding of fractured fragments is recommended for management. Rehydration of fragments improves bonding and fracture resistance. Therefore, the aim of this study was to compare the fracture resistance of the reattached tooth fragment of the incisor crown after rehydration using either a steamer or a humidifier. MATERIALS AND METHODS: Bovine teeth were used as a model. Fractured fragments were divided into three groups: Group I (no rehydration), Group II (rehydration by humidifier), and Group III (rehydration by steamer). Fragments were reattached using a standard bonding protocol. Fracture resistance was tested using a universal testing machine. Statistical analysis was performed using analysis of variance and Chi-square tests. RESULTS: The force required to fracture the reattached fragments was significantly higher in Group II (humidifier) compared to Group I (no rehydration) (P = 0.005). Group III (steamer) had a force value similar to Group I, indicating no significant improvement in fracture resistance with steamer rehydration. The temperature inside the steam-based chamber reached an average of 95.7°C with 95% humidity, whereas the conventional humidification chamber had an average temperature of 39.2°C and 84% humidity. CONCLUSION: Within the limitations of the present study, the rehydration protocol using a steam-based chamber was found to have a significantly lower force required to fracture the reattached fragments as compared to humidifier-based chamber. This was not significantly different from the fragments which were reattached without rehydration.

[Impact of GuttaFlow Bioseal sealer on the vertical fracture resistance of oval-shaped canals].

PURPOSE: To investigate the effect of GuttaFlow Bioseal root canal sealer on the vertical root fracture resistance of oval-shaped root canals. METHODS: Sixty orthodontically subtracted maxillary and mandibular single-rooted premolar teeth were scanned with CBCT. Oval canals were eligible when the buccolingual diameter of the canal was greater than or equal to two times the mesiodistal diameter at a distance of 5 mm from the root apex. Thirty single-rooted premolars with oval-shaped root canals were prepared to F2 using the Protaper system and then randomly divided into the GuttaFlow Bioseal filling group and iRoot SP filling group. Each group was further divided for root canal filling using warm vertical compression, cold lateral condensation and single cone techniques. Five single-rooted premolars was chosen as a negative control group. After 30 days of storage in a constant thermotank at 37 ℃ and 100% humidity, the filled roots were vertically placed into a cylindrical model of self-polymerizing acrylic resin. Subsequently, the samples were fixed on the lower plate of a universal testing machine, and a ball of 4 mm in diameter was applied vertically with a downward pressure at a speed of 1 mm/min until fracture occurred. The load values were recorded in Newtons. The data were analyzed using SPSS 29.0 software package. Fracture patterns were examined under microscope. RESULTS: T test results showed no significant difference between the GuttaFlow Bioseal-filled and iRoot SP-filled groups (P=0.321). One-way ANOVA showed a significant difference in vertical fracture resistance between the groups(P＜0.05), and LSD analysis showed that the GuttaFlow Bioseal-filled sample teeth were significantly more resistant to vertical fracture than the iRoot SP when using the thermal vertical compression filling method and the single-tip method(P＜0.05). In contrast, the GuttaFlow BIoseal-filled group was significantly less resistant to vertical fracture than the iRoot SP group when using the cold lateral compression filling method(P＜0.05). CONCLUISIONS: GuttaFlow Bioseal has the potential to improve root resistance to vertical fracture when filling root canals using the thermal vertical pressurization method and the single-tip method, but more clinical trials are needed to validate this result and its long-term prognosis.

Influence of Cavity Designs on Fracture Resistance: Analysis of the Role of Different Access Techniques to the Endodontic Cavity in the Onset of Fractures: Narrative Review.

Objectives: In recent years, new endodontic access techniques have been proposed with the aim of preserving as much dental tissue as possible for subsequent prosthetic rehabilitation. It has indeed been demonstrated that the success of this therapy is essential and dependent on the proper execution of endodontic cavity access. The main objective is to provide a comprehensive and up-to-date overview of the new access techniques in endodontics in order to guide clinical practice toward a more precise and qualitative approach. As of today, there is still no universally standardized and recognized taxonomy for the different access cavity designs described in the literature. It has been observed that there are various nomenclatures in the literature. The cavity access designs described mainly in the literature can be categorized into six groups: Traditional Access Cavity (TradAC), Conservative Access Cavity (ConsAC), Ultra-Conservative Access Cavity (UltraAC), Truss Access Cavity (TrussAC), Caries-Guided Access Cavity (CariesAC), and Restoration-Guided Access Cavity (RestoAC). Materials and Methods: The drafting of this narrative review followed the indications of the SANRA (Scale for the Assessment of Narrative Review Articles). A search for scientific articles was conducted on the PubMed and SCOPUS databases, using the following search query: ((truss) OR (conservative) OR (ninja) OR (traditional)) AND access AND endodontic. Results: The initial search yielded a total of 941 articles. After removing duplicates using EndNote X8 software, the number of articles decreased to 785. By applying the inclusion and exclusion criteria, a total of 64 articles were obtained. Among these, 20 articles were finally selected for the purposes of this review, 11 literature reviews and 9 ex-vivo studies. Conclusion: Studies on fracture resistance have yielded heterogeneous results. For anterior teeth, studies do not find a significant relationship between different endodontic access cavities and fracture resistance. However, in the posterior sector, there is more discrepancy and many positive results for minimally invasive access cavities seem to relate to molars. Therefore, it can be concluded that the evidence supporting the influence of endodontic preparations on dental fracture resistance is still limited. Research on new endodontic access techniques holds significant clinical relevance in contemporary endodontics. The evolution of dental technologies, including cone beam computed tomography (CBCT) and computer-guided cavity preparation, has ushered in the era of minimally invasive endodontics. This shift aims to enhance the precision and quality of endodontic treatments while preserving maximum healthy dental tissue for subsequent prosthetic rehabilitation. The success of endodontic therapy is closely tied to the proper execution of access to the endodontium, influencing all phases of endodontic treatment and playing a role in determining fracture resistance for subsequent rehabilitation phases. The dichotomy between traditional and minimally invasive approaches has spurred clinical investigations. Specifically, within the scientific community, doubts have been raised about the potential limitations of minimally invasive access cavities. Concerns include their impact on canal orifice localization and raise questions about their influence on the overall success of endodontic treatment. This review holds clinical significance as it sheds light on the evolving landscape of endodontic access techniques, analyzing the anatomical trajectory, carefully examines the transition to minimally invasive approaches, and critically assesses existing scientific evidence and concerns surrounding these developments, contributing to an informed decision-making process in clinical practice.

[The use of mineral trioxide aggregate for treatment of children with complications of dental trauma]. / Primenenie mineral trioksid agregata dlya lecheniya detei s oslozhneniyami travmy postoyannykh zubov.

THE AIM: Jf the study was to assess the efficacy of mineral trioxide aggregate for treatment of children with complicated permanent teeth trauma. MATERIAL AND METHODS: The study comprised 29 children aged 6-13 years (mean age 8.6±1.7 years) with 36 injured constant teeth, from which 30 had immature roots, 27 (75%) teeth had necrotic pulp at baseline examination, 12 (33.3%) teeth showed radiological signs of external imflammatory root resorbtion, 2 teeth were diagnosed with of the root fracture (5.6%). MTA was used for pulp regeneration procedure in 25 (69.5%) teeth, external closure of resorbtion site in 3 (8.3%) teeth, root canal filling in 4 (11.1%) teeth, apical plug creation in 4 teeth (11.1%). The patients were folowed up for 1 to 9 years. RESULTS: From 36 teeth only one was extracted 9 years after regenerative endodontic procedure because of cervical root fracture. In 2 teeth with external imflammatory resorbtion progession of replacement resorption took place, in 1 tooth necrosis of regenerated pulp tissue occurred 2 years after the procedure because of restoration marginal seal failure. In 25 teeth favorable outcome was registered with stabilisation of external root resorbtion, continous root growth in 24 teeth and radioluscent lesions healing in 6 teeht showing them at baseline examination. Change of external imflammator root resorbtion to replacement resorption was detected in 1 teeth from 3 with external closure of resorbtion site. Root calan filling with MTA was performed in 3 avulsed teeth with replantation delayed for more than 1 day and in 1 tooth with root fracture. All teeth were clinically asymptomatic during more than 5 years follow-up. Favorable outcome was received in all cases of apicl plug formation. CONCLUSION: MTA is highly effective for preservation of constant teeth in children with clinically complicated situations. In many cases with hopeless long-term prognosis for a teeth MTA allows stabilization of dental tissue level with the teeth being an object for guided tissue regeneration.

Evaluation of colour change, marginal adaptation, fracture strength, and failure type in maxillary and mandibular premolar zirconia endo-crowns.

OBJECTIVES: The objective of this in vitro study was to evaluate the effects of different preparation designs on the mean colour change (ΔE*), marginal adaptation, fracture resistance, and fracture types of maxillary and mandibular premolar endocrowns (ECs). METHODOLOGY: A total of 40 extracted maxillary and mandibular premolars were treated endodontically, and each type was subdivided according to the remaining axial height (remaining walls on all surfaces; 2-4 mm) and 2 mm inside the pulp chamber. Specimens were immersed in coffee for 14 days, ΔE* was determined, marginal adaptation was observed, fracture forces test was conducted, and the samples were examined visually at 10× magnification to evaluate failure type and identify fracture origin. The data were entered and analyzed using Statistical Package for Social Sciences, and significance between and within groups was evaluated through ANOVA. The p-value ≤ 0.05 was considered statistically significant. RESULTS: The ΔE* values of the maxillary premolar with 2 mm axial height were the highest (6.8 ± 0.89 units), whereas the lowest value was observed in the mandibular premolar with 4 mm axial height (2.9 ± 0.53 units). Significant differences (p < 0.05) in teeth and design were observed. The marginal adaptation of the mandibular premolar with 4 mm axial height was the highest (30.20 ± 1.53 µm), whereas the lowest marginal adaptation was observed in the maxillary premolar with 2 mm axial height (14.38 ± 0.99 µm), and the difference was statistically significant (p < 0.05). The maximum fracture force was observed in maxillary premolars with 2 mm axial height (2248.15 ± 134.74 N), and no statistically significant difference (p = 0.07) was observed between maxillary and mandibular premolars at 4 mm axial height. CONCLUSION: The recorded ΔE* values of the ECs were within clinically acceptable values or slightly higher, and the marginal adaption values were within acceptable and recommended clinical values in µm. EC preparation with 2 mm axial height in both arches recorded the highest fracture forces. Type III (split fracture) failure was recorded as the highest in the maxillary and mandibular premolar ECs with different axial wall heights.

Management of oblique root fracture in the middle third of two maxillary immature central incisors with severe caries in mixed dentitions: a case report.

Mid-root fractures are rare injuries in young permanent teeth and tend to have poor prognoses. This study presents a case of oblique root fracture of both maxillary immature central incisors in the middle third accompanied by delayed dental visit and severe caries of all primary teeth. After restoring all the primary and permanent teeth that needed stabilization, the coronal fragments were repositioned and stabilized with a flexible splint consisting of orthodontic wire and composite resin. A comprehensive and sequential dental treatment for other oral diseases and oral hygiene instructions were provided. A 16-month follow-up revealed that the two injured young permanent incisors were healed, surrounded by hard tissues and continued to grow both in length of the root and thickness of the root canal wall, with significant improvement in oral hygiene. Based on the outcome of this case, initial stabilization without endodontic therapy could be considered a successful treatment modality for young permanent teeth with oblique root fracture due to the growth of fractured teeth with vital pulp and the maintenance of natural dentition.

Effect of continuous vs sequential chelation on the mechanical properties of root dentin: An ex vivo study.

OBJECTIVES: To evaluate the mechanical properties of root canal dentin treated with sodium hypochlorite (NaOCl) in combination with hydroxyethylidene diphosphonic acid (HEDP) or ethylenediaminetetraacetic acid (EDTA). METHODS: For testing fracture resistance, 45 single-rooted teeth were instrumented and irrigated with NaOCl/HEDP, NaOCl/EDTA, or distilled water. Fifteen untreated teeth served as control. After obturation, specimens from the experimental groups were thermocycled, dynamically-loaded, and then statically-loaded in a universal testing machine until failure. For flexural strength analysis, 15 teeth were instrumented and irrigated with NaOCl/HEDP or NaOCl/EDTA. Root segments were sectioned into dentin bars and tested for flexural strength using a universal testing machine. For microhardness evaluation, 20 teeth were instrumented and irrigated with NaOCl/HEDP or NaOCl/EDTA. Dentin disks from the coronal-third of each root segment were prepared, one before and one after irrigation, for microhardness testing with a Knoop hardness tester. RESULTS: The highest fracture resistance was recorded in the untreated group, and the lowest in the EDTA group. Although the HEDP group had higher fracture resistance than the EDTA group, the distilled water group demonstrated even greater fracture resistance than the HEDP group. Specimens treated with HEDP had significantly higher flexural strength and microhardness values when compared with those treated with EDTA. CONCLUSION: The fracture resistance, flexural strength, and microhardness of root canal dentin were higher when root canals were irrigated with NaOCl/HEDP, when compared with NaOCl/EDTA. CLINICAL SIGNIFICANCE: Irrigating root canals with NaOCl combined with HEDP significantly improves the mechanical integrity of root canal dentin compared to the use of NaOCl with EDTA.

A protocol for a comparative evaluation of the fracture resistance of endodontically treated teeth reinforced with Cention N, resin-modified glass ionomer cement (RMGIC) and short fiber reinforced flowable composite as an intraorifice barrier.

Background: Endodontic treatment is the most common method for resolving pulpal and periapical pathology. However, various studies have reported that almost 11%-13% of all teeth that undergo extraction after endodontic treatment show the presence of cracks, craze lines, and vertical root fractures. Teeth with inadequate post endodontic restoration are more prone to fracture and coronal leakage, resulting in the diffusion of oral fluids, bacteria, bacterial products, and possibly root canal treatment failure. Furthermore, studies have advocated the use of endodontically treated teeth with restorative materials that have a similar or higher elastic modulus than the tooth for providing stiffness against forces that cause root fracture. Intraorifice barriers made of restorative materials that can bond to radicular dentin could thus be used to reinforce the radicular dentin while also preventing coronal microleakage. Although the sealing ability of intraorifice barriers has been widely compared in the literature, there have been few studies on the strengthening effect of the materials used in the study as intraorifice barriers when placed into the root canal. As a result, the current in vitro study aims to assess the effect of various materials as intraorifice barriers (Cention N, Resin modified glass ionomer cement, and short fiber reinforced flowable composite) on the force required fracture teeth after root canal treatment. Methods: This in vitro study will be done on extracted human mandibular premolars with single root canal where after doing root canal treatment 2-3 mm obturating material would be replaced by intra orifice barriers (Cention N, resin modified glass ionomer cement [RMGIC], and short fiber reinforced flowable composite). The force required to fracture teeth will be calculated using universal testing machine.

Influence of remaining coronal tooth morphology with resin abutment and fiber post on static and dynamic fracture resistances.

This study aimed to clarify the fracture resistance of resin abutments built on endodontically treated roots with the remaining coronal teeth via static and cyclic loading tests. Endodontically treated bovine roots, which had a remaining coronal tooth covered with an occupied area for a quarter and half of the circumference at the tensile side or covered the circumference at both the tensile and compressive sides, were fabricated to build up to the resin abutment. Fracture resistance was evaluated via static and cyclic loading tests by applying a load of 30° to the tooth axis. Half of the circumference of the remaining coronal tooth showed a significantly higher static fracture load and survival rate. The remaining coronal tooth on the compressive side improved the dynamic fracture resistance associated with severe fractures. The occupied area and location of the remaining coronal tooth affected the static and dynamic fracture resistances.

Effect of preparation design on the fracture resistance and fracture patterns of 3D printed one-piece endodontic crowns.

STATEMENT OF PROBLEM: The impact of various preparation designs on the fracture resistance and fracture type of mandibular premolars restored with 3 dimensionally (3D) printed, 1-piece endodontic crowns remains unclear. PURPOSE: The purpose of this study was to investigate the effect of different preparation designs on the fracture resistance and fracture patterns of mandibular premolars restored with 3D printed 1-piece endodontic crowns after thermal aging. MATERIAL AND METHODS: Forty-five freshly extracted mandibular premolars received 3 different preparation designs: with at least 2 intact cuspal walls (2CW), with only 1 intact cuspal wall (1CW), and no cuspal wall present (NoCW). One-piece endodontic crowns were designed by using a computer-aided design (CAD) software program, 3D printed, cemented to the prepared teeth with self-adhesive resin cement, and thermocycled between 5 °C and 55 °C in artificial saliva. Subsequently, all specimens were subjected to a fracture test. The results were statistically analyzed using 1-way ANOVA (α=.05), and fracture types of all specimens were examined using a light microscope. RESULTS: The analysis of fracture resistance values across separate designs revealed no statistically significant differences (P>.05). Mean fracture resistance values were 724.5 N in 2CW, 713 N in 1CW, and 861 N in NoCW. In 2CW and 1CW, the 1-piece endodontic crowns mostly displayed Type III fractures, whereas those in NoCW exhibited a combination of Type II and Type III fractures. CONCLUSIONS: The mandibular premolar 1-piece endodontic crowns tested in this study exhibited similar fracture resistance and type of fracture with different preparation designs.

Developing evidence-based clinical imaging guidelines for the diagnosis of vertically fractured teeth.

OBJECTIVES: This study aimed to develop an evidence-based clinical imaging guideline for teeth suspected with vertical root fractures. METHODS: An adaptation methodology based on the Korean Clinical Imaging Guidelines (K-CIG) was used in the guideline development process. After searching for guidelines using major databases such as Ovid-Medline, Elsevier-Embase, National Guideline Clearinghouse, and Guideline International Network, as well as domestic databases such as KoreaMed, KMbase, and KoMGI, two reviewers analyzed the retrieved articles. The retrieved articles were included in this review using well-established inclusion criteria. RESULTS: Twenty articles were identified through an online search, of which three were selected for guideline development. Based on these three guidelines, this study developed specific recommendations concerning the optimal imaging modality for diagnosing teeth suspected of vertical root fractures. CONCLUSIONS: Periapical radiography is the preferred method for assessing teeth with mastication-related pain and suspected vertical root fractures. However, if intraoral radiographs do not provide sufficient information about root fractures, a small FOV CBCT may be considered. However, the use of CBCT in endodontically treated teeth is significantly constrained by the presence of artificial shading.

Modeling fracture in multilayered teeth using the finite volume-based phase field method.

The present work, utilizing the finite volume-based phase field method (FV-based PFM), aims to investigate the initiation and propagation of cracks in the second molar of the left mandible under occlusal loading. By reconstructing cone beam computed tomography scans of the patient, the true morphology and internal mesostructure of the entire tooth are implemented into numerical simulations, including both 2D slice models and a realistic 3D model. Weibull functions are introduced to represent the tooth's heterogeneity, enabling the stochastic distribution characteristics of mechanical parameters. The results indicate that stronger heterogeneity leads to greater crack tortuosity, uneven damage distribution, and lower fracture stress. Additionally, different cusp angles (50° and 70°) and pre-existing fissure morphologies (i.e., U-shape, V-shape, IK-shape, I-shape, and IY-shape) also significantly affect the mechanical performance of the tooth. The study reveals that different cusp angles affect the location of crack initiation. Overall, this work demonstrates the utility of the FV-based PFM framework in capturing the complex fracture behavior of teeth, which can contribute to improved clinical treatment and prevention of tooth fractures. The insights gained from this study can inform the design of dental crown restorations and the optimization of cusp inclination and contact during clinical occlusal adjustments.

Fracture Resistance and Failure Mode of Polyethylene Fiber-reinforced Resin-based Restorations in Structurally Compromised Premolars: an in Vitro Study.

OBJECTIVE: To evaluate the effect of polyethylene fiber-reinforcement on the fracture resistance and fracture mode of extensive resin-based composite (RBC) restorations in structurally compromised maxillary premolars. METHODS AND MATERIALS: Maxillary premolars (54) with specific dimensions and extracted for orthodontic reasons were used. Following mesio-occluso-distal (MOD) cavity preparation and endodontic access, teeth were randomly assigned to one of three restorative protocols (n=18): RBC applied incrementally (I) or reinforced with woven polyethylene fibers (Ribbond) placed horizontally (H) or U-shaped (U). Restored teeth were stored for 45 days in distilled water at 37°C and then loaded monotonically until fracture. Half of the specimens in each group received axial loading (A) and the other half was loaded paraxially (PA). Fracture load data was assessed using two-way analysis of variance and Tukey's post hoc test for multiple comparisons (α=0.05). The fracture initiation and propagation path were analyzed using stereomicroscopy and scanning-electron microscopy. RESULTS: No significant differences were observed for the fracture strength among loading configurations, except for groups IA (825 N) and HA (553 N). Fracture initiated and propagated mainly at and through the RBC restoration in the I group, whereas a shift to the interface was observed in both polyethylene fiber-reinforced groups. Blocking and bridging of cracks were identified around the fibers, especially in specimens of group U. CONCLUSIONS: Incorporation of woven polyethylene fibers to reinforce extensive MOD resin-based composite restorations on endodontically treated premolars reduced the occurrence of cohesive fractures in the restorative material but was unable to increase the fracture resistance of the affected teeth.

Long-term complications and management of dental trauma in the adult patient - Part 1: fractured teeth, pulpal complications and resorption.

Dental trauma is one of the most common injuries encountered in the younger population. This can have a long-term impact on the patient's overall quality of life as they may have to deal with the sequelae of these injuries for years to come. Young boys experience dental trauma more frequently than young girls and one of the most common outcomes of these injuries are fractured teeth. This first paper in a two-part review series aims to provide an overview of dental trauma followed by a discussion on management of fractured teeth, associated pulpal complications and resorption. These can be uncomplicated fractures involving enamel and/or dentine, or complicated fractures involving enamel, dentine and pulp. They can involve the crown, the crown and root together, or present solely as root fractures. Pulpal complications can lead to pulp necrosis or pulp canal obliteration. Resorption can be internal or external, inflammatory, or replacement type. The management of each of these injuries begins with a thorough assessment followed by initiating emergency treatment to stabilise the presenting condition. This is followed by a long-term treatment plan which aims to address the patients' aesthetic and functional requirements and provide the patient with the most suitable treatment outcome in the hope to improve their sense of wellbeing and overall quality of life.

Impact of Pericervical Dentin on Fracture Resistance of Endodontically Treated Posterior Permanent Teeth: A Systematic Review and Meta-analysis.

OBJECTIVE: The main aim of this present systematic review is to evaluate if the preservation of pericervical dentin (PCD) increases the fracture resistance of endodontically treated permanent posterior teeth. MATERIALS AND METHODS: Two independent reviewers conducted a comprehensive review of all published studies from 2007 (1/1/2007) to 2023 (31/5/23) since the concept of PCD first appeared in the literature in 2007. Searches were conducted in multiple electronic database engines: PubMed, Scopus, EBSCO (Dentistry and oral health sciences), Web of Sciences (WOS), Cochrane, Google Scholar and Open Grey, Ovid and Shodhganga, in addition to cross-references and hand search. Articles were chosen according to a certain inclusion and exclusion criteria, which, in brief, are laboratory-based studies published in English that assess the impact of PCD on fracture resistance of endodontically treated permanent posterior teeth. Using domains, such as sample size, sample dimensions, and control group as quality assessment criteria, evaluated the selected articles and classified them according to their risk of bias into low, moderate, and high. A meta-analysis was conducted using random effects modeling at a significance level of p < 0.05. RESULTS: A total of studies 6,043 were retrieved from 10 different electronic search databases and hand searches, but only 12 laboratory-based studies were selected after removing duplicates and applying the eligibility criteria. Of the included 12 studies, nine studies showed low risk of bias and three studies showed moderate risk of bias. Two studies showed related data for meta-analysis, the difference observed between the two studies is statistically non-significant. CONCLUSION: Based on the results of the study, there is evidence to support that PCD preservation offers fracture resistance to the endodontically treated posterior teeth. CLINICAL SIGNIFICANCE: The practice of conservative cavity preparation and avoiding the usage of instruments with high taper increases the fracture resistance of the tooth by retaining the PCD. How to cite this article: Haridoss S, Rajendran M, Swaminathan K, et al. Impact of Pericervical Dentin on Fracture Resistance of Endodontically Treated Posterior Permanent Teeth: A Systematic Review and Meta-analysis. J Contemp Dent Pract 2024;25(4):372-385.

Pre-Sealing of Endodontic Access Cavities for the Preservation of Anterior Teeth Fracture Resistance.

OBJECTIVE: Sodium hypochlorite solution (NaOCl) is an effective canal irrigant but interferes with the mechanical features of dentin and the bonding capability of adhesives when restoring endodontically treated teeth. This study evaluated whether access cavity resin sealing before using canal irrigant would augment the resistance of endodontically treated anterior teeth against fracture. METHODS: Sixty maxillary incisors underwent endodontic treatment in five groups (n = 12). Irrigation with 5.25% NaOCl and 17% ethylenediaminetetraacetic acid (EDTA) was performed in all groups except for Group 5. After root canal obturation, in Group 1, the access cavity was kept unrestored. In Group 2, immediate restoration after obturation was achieved. For Group 3, delayed restoration after 1 week was provided. In Group 4 (pre-sealed), before canal irrigation, the dentin surface of access cavities was sealed using self-adhesive composite resin (Vertise Flow) and then restored after obturation. In Group 5, which was saline irrigated, immediate restoration was performed. After storage and thermal cycling for 5000 cycles at 5°C-55°C with a dwell time of 15 s and a transfer time of 5 s, teeth were statically loaded by a universal testing machine until a fracture occurred. Data were collected as the fracture resistance (FR) and analyzed using the one-way analysis of variance and Tukey's tests. RESULTS: FR significantly differed between all groups (p < 0.001). The lowest FR was recorded in the unrestored group (284 ± 86 N), which was not statistically different from the immediately restored group (p = 0.065). The pre-sealed group exhibited the highest FR value (810 ± 127 N, p ≤ 0.02 vs. other groups). The FR of the saline-irrigated and delayed restored groups was almost similar (p = 0.13). CONCLUSIONS: NaOCl/EDTA irrigation resulted in an adverse effect on FR. Delayed restoration could reduce this adverse effect. Access cavity pre-sealing with flowable composites led to a higher FR than conventional methods and may be considered an effective step during treatment procedures.

Traumatic dental injuries and molar incisor hypomineralization: a cross-sectional study of schoolchildren from southern Brazil.

PURPOSE: To describe the prevalence and the variables associated with TDIs in schoolchildren aged 8 to 14 years in Estância Velha city in southern Brazil, placing emphasis on molar incisor hypomineralization. METHODS: Students enrolled in public schools of a medium-sized city in the southern Brazil were selected using cluster random sampling. Clinical examinations assessed molar incisor hypomineralization-MIH (European Academy of Pediatric Dentistry criteria), dental caries (DMFT index), and TDIs (O'Brien's criteria). Socioeconomic and demographic variables were assessed using a standardized questionnaire. Prevalence ratios were estimated using Poisson regression (p < 0.05). RESULTS: 513 students (54.8% female), with a mean age of 11.6 (± 1.9) years, participated in the study. The prevalence of TDIs was 11.3%, with enamel fracture representing 90.4%. The high prevalence of traumatic dental injuries was associated with MIH (PR: 2.22 CI: 1.27; 3.87; p < 0.01) and overjet > 3 mm (PR: 2.03 CI 1.19; 3.45; p < 0.01). CONCLUSION: The sample of schoolchildren from southern Brazil had a low prevalence of traumatic dental injuries. Molar incisor hypomineralization and increased overjet were associated with the higher prevalence of traumatic dental injuries.

The effect of ferrule and core material on fracture resistance of endodontically treated anterior teeth restored with ceramic crowns after artificial aging.

OBJECTIVES: To assess the influence of ferrule and core type on the fracture strength of endodontically treated anterior teeth (ETAT) and identify the failure mode type and distribution across different core types and ferrule conditions. METHODS: Sixty extracted human central incisors were endodontically treated, decoronated and divided into two main groups (F=with ferrule, NF=no ferrule). Each main group was further subdivided into three subgroups according to the core material used: direct composite cores (DC), Ribbond fibre-reinforced composite cores (RIB-DC), and glass fibre post (GFP) with direct composite cores (GFP-DC). All specimens received E.max crowns and underwent thermal cycling and cyclic loading. Subsequently, the fracture resistance was tested with static loads applied to the crown restoration. Two-Way ANOVA and Chi square tests identified significant differences among the groups (p < 0.05). RESULTS: The means and standard deviations (SD) of fracture loads in Newtons (N) for specimens in the F subgroups were RIB-DC: 465.0 (104.20), GFP-DC: 367.6 (79.59), DC: 275.8 (68.48), and in NF subgroups were RIB-DC: 110.8 (24.33), GFP-DC: 95.6 (25.47), DC: 67.4 (7.46). Specimens with ferrule yielded significantly higher fracture loads than those without ferrule (p = 0.0054). In the F groups, fracture loads of specimens with RIB-DC cores were significantly higher than those with GFP-DC (p = 0.0019) and those with DC (p = 0.0001). Moreover, fracture loads for the GFP-DC were significantly higher than those for the DC (p = 0.0026). The GFP-DC specimens showed the highest incidence of catastrophic failures (p = 0.0420). CONCLUSIONS: Using fibre-reinforced composite (FRC) cores significantly increased fracture resistance in ETAT with ferrule. The failure modes repairable and possibly repairable were dominant in most specimens. CLINICAL SIGNIFICANCE: When restoring ETAT with insufficient coronal tooth structure, preserving 2 mm of tooth structure ferrule and preparing cores with FRC can increase fracture resistance and reduce the incidence of non-repairable catastrophic fractures of teeth.