Restoration of the root canal treated tooth

Opinions of UK General Dental Practitioners on the Restoration of Posterior Root Filled Teeth: a Vignette Survey

OBJECTIVE

To investigate factors which influence UK general dental practitioners (GDPs) when restoring posterior root filled teeth.

METHOD

An electronic survey was designed to explore current strategies of treatment of posterior root filled teeth by UK-based GDPs working in primary care. Three vignette cases included in the questionnaire explored a variety of tooth, patient, and financial factors. The survey was distributed by email and social media platforms between December 2018 and February 2019.

RESULTS

A total of 528 valid responses were collected. The majority of participants (84.1%) regularly restored posterior root filled teeth with an indirect restoration. Presence of persistent symptoms post root canal treatment (RCT) completion would impact the management of 85% of the surveyed respondents. Referral to a specialist, deferral of provision of the definitive restoration, and fear of litigation were reported by the GDPs as influencing factors.

CONCLUSION

This survey highlights that decision making regarding restoration of root filled teeth is a multifactorial process. Tooth, patient, and financial factors were all shown to influence the restorative management of the posterior root filled teeth.

Influence of restorative materials on the mechanical properties of maxillary first molars with different degrees of cryptic fractures and defects: A finite element analysis

This study aimed to apply finite element analysis to evaluate the effects of pile materials with different elastic moduli and cement materials on the stress distribution between the remaining tooth tissue and cryptic fracture defects. A three-dimensional finite element model was established for 20 maxillary first molars with hidden fissures and mesial tongue-tip defects. Two levels of hidden cracks and three types of pile and adhesive materials were used in the design. The stress distribution and maximum stress peak in the remaining tooth tissue and crack defects were determined by simulating the normal bite, maximum bite, and lateral movement forces. When titanium posts, zinc phosphate binders, and porcelain crowns were used to repair the two types of deep cracked teeth, the maximum principal stress at the crack and dentin was the smallest. As the crack depth increased, the maximum principal stress of the residual dentin and crack defects increased.

Special considerations in paediatric dental trauma

Traumatic dental injuries (TDIs) in the paediatric population are common and frequently seen in general dental practice. The management of TDIs can be challenging and, in most cases, the General Dental Practitioner is tasked with the initial assessment and emergency treatment. Patients and their families typically attend with elevated levels of distress, which is complicated by the limited dental experience of some children. Behaviour management is essential and helps prepare patients for dental care at both their emergency and follow-up appointments. Early and accurate diagnosis in combination with appropriate treatment contributes to favourable outcomes for traumatised teeth. Early discussions with or referral to paediatric dental teams for management of complex TDIs is encouraged, however shared follow-up care is beneficial over the long-term. In specific cases, initial dental treatment can be delayed by a few days to a subsequent appointment, allowing the dental team to book sufficient time for the treatment and for the patient and their families to prepare. Education of the patients and adults with parental responsibility is essential to manage expectations, explain likely complications and encourage attendance for long-term follow-up visits. This paper discusses the management of paediatric patients to aid the primary care practitioner in providing effective immediate and long-term care.

A narrative review of cracks in teeth: Aetiology, microstructure and diagnostic challenges

OBJECTIVES

To summarize the available evidence of crack formation in teeth and to discuss the limitations of the current clinical diagnostic modalities for crack detection in teeth.

BACKGROUND

Cracks are a common clinical finding in teeth and yet clinicians still struggle to identify the full extent and orientation of cracks for their appropriate timely management. The biomechanics of crack development can be due to multiple factors and can differ from an unrestored tooth to a restored or endodontically treated tooth.

DATA & SOURCES

This narrative review has been designed following the guidelines published by Green et al. 2006 [1] Published literature in the English language that addresses the objectives of this review up to July 2022 was sourced from online databases and reference lists. The relevance of the papers was assessed and discussed by two reviewers. A total of 101 publications were included in this narrative review.

CONCLUSIONS

The initiation and development of cracks in teeth are likely linked to an interplay between the masticatory forces and fracture resistance of the remaining tooth structure. From the identified literature, the quality and quantity of remaining tooth structure in a restored or endodontically-treated tooth affects the biomechanics of crack development compared to an unrestored tooth. The extent, orientation, and size of the cracks do affect a clinician's ability to detect cracks in teeth. There is still a need to develop reliable diagnostic tools that will accurately identify cracks in teeth beneath restorations to enable effective monitoring of their propagation and provide appropriate interventions.

CLINICAL SIGNIFICANCE

The development and propagation of cracks in an unrestored tooth differ greatly from a restored and endodontically treated tooth; mainly linked to the quantity and quality of the remaining tooth structure and the forces acting on them. Identifying the extent of cracks in teeth remains challenging for early clinical intervention.

Effect of Ferrule Location on Fracture Resistance of Maxillary Premolars: An In Vitro Study

Objectives

The present study aimed to assess the effect of ferrule location on fracture resistance of maxillary premolars.

Materials and Methods

A total of 72 extracted human maxillary premolars were selected and randomly assigned to six groups (n = 12 in each) considering ferrule location: circumferential ferrule (CF), without ferrule (WF), buccal ferrule (BF), lingual ferrule (LF), mesial ferrule (MF), and buccal-lingual ferrule (BLF). Cast posts were cemented into the prepared post spaces. Following conventional impression, Ni-Cr crowns were cemented to the specimens. After thermocycling (5,000 cycles, 5-55°C), the specimens were loaded at 45° in a universal testing machine until fracture. Data were analyzed with one-way ANOVA, Kolmogorov-Smirnov, and Tamhane tests.

Results

The maximum and minimum mean fracture resistance were related to the CF (1,143.84 N) and WF (514.89 N) groups, respectively, (P = 0.039). Fracture resistance in the BF (933.67 N) and BLF (874.01 N) groups was significantly higher than in the MF group (617.54 N) (P = 0.001). There was no significant difference between the MF, LF (722.89 N), and WF groups in terms of fracture resistance (P > 0.05).

Conclusion

Teeth with CF showed maximum fracture resistance. The location of the ferrule effects on the fracture resistance of maxillary premolars and also the mode of failure.

Effect of Dental Glass Fiber Posts on Root Stresses and Fracture Behavior of Endodontically Treated Maxillary Central Incisors: A Finite Element Analysis Study

OBJECTIVE

 In this work, the influence of glass fiber posts with different designs on the root stress that had endodontic treatment was examined using the finite element method.

METHOD

 Using two distinct materials (metal and glass fiber) and two different prototypes (tapered and parallel-sided), four three-dimensional (3D) finite element models of an upper central incisor were made and studied. Each 3D model received an oblique loading of 100 N. All forces were dispatched as distributed pressure to the aforementioned region. There were no considerations made for potential stresses when performing the endodontic procedure. The endodontic treatment was conducted without taking into account any potential stressors. The root stresses were then recorded.

RESULTS

The largest tensile stress is often focused at the apical third of the post and post/cement contact, as well as at the coronal third of the root on both the labial and palatal sides of the root, independent of the post's design and material. Restoration of endodontically treated maxillary central incisors with glass fiber posts has been shown to have less stress concentration than titanium posts. Regardless of the post materials employed, the tapered post design generated a higher tensile stress distribution than the parallel side design.

CONCLUSIONS

 Prefabricated fiber posts used in model restoration resulted in more evenly distributed stress and less concentrated stress on the root. Reduction in modulus of elasticity of post materials used generally shows less stress concentration.

Clinical decision-making in complex endodontic cases between postgraduate students across dental specialties at a UK dental school: A pilot study

INTRODUCTION

Treatment decisions for a heavily restored endodontically treated tooth vary amongst clinicians owing to multitude of factors. This phenomenon not only often poses dilemmas to clinicians of different clinical backgrounds, but also exerts a degree of treatment difficulty to the treating clinician. Previous studies indicated that specialty training and clinical experience significantly impacted clinical decision-making process.

MATERIALS AND METHODS

Master of Science postgraduate students in endodontics, prosthodontics, periodontics, oral surgery and implantology participated in a questionnaire-based cross-sectional study. The dental specialties were further categorised into restorative and surgical dentistry. A multiple-choice questionnaire with three clinical cases was distributed to the students. Data were analysed for trends using descriptive statistics.

RESULTS

There was a 44% response rate; the majority of respondents were from restorative dentistry specialties. Cases 1 and 2 were rated as moderate to high difficulty, and Case 3 was predominantly rated as high difficulty with procedure predictability being the main factor affecting their clinical decision-making in three cases. Endodontic retreatment was selected as the preferred treatment in Cases 1 and 2 and periradicular surgery in Case 3. The students were fairly confident in managing Cases 1 and 2, but not in Case 3. Referral patterns were consistent in Cases 1 and 2 with endodontists being the first choice of referral except for Case 3 where 48% preferred to refer to oral surgeons and 35% choosing endodontists. Some indication of differences between specialties were noted throughout. Years in practice appeared to be related to the importance of predictability in Case 3 only.

CONCLUSION

Considerable inter-clinician variability was noted whereby specialty postgraduate training impacted on clinical decision-making. Overall, procedural predictability, technical difficulty, risk of damage to the tooth and patient preference were the most highly ranked factors affecting clinical decision-making. Evidence-based treatment guidelines and dental curricula should be reviewed to enhance inter-clinician agreement in clinical decision-making, ultimately improving patient care.

Tissue Engineering with Stem Cell from Human Exfoliated Deciduous Teeth (SHED) and Collagen Matrix, Regulated by Growth Factor in Regenerating the Dental Pulp

Maintaining dental pulp vitality and preventing tooth loss are two challenges in endodontic treatment. A tooth lacking a viable pulp loses its defense mechanism and regenerative ability, making it more vulnerable to severe damage and eventually necessitating extraction. The tissue engineering approach has drawn attention as an alternative therapy as it can regenerate dentin-pulp complex structures and functions. Stem cells or progenitor cells, extracellular matrix, and signaling molecules are triad components of this approach. Stem cells from human exfoliated deciduous teeth (SHED) are a promising, noninvasive source of stem cells for tissue regeneration. Not only can SHEDs regenerate dentin-pulp tissues (comprised of fibroblasts, odontoblasts, endothelial cells, and nerve cells), but SHEDs also possess immunomodulatory and immunosuppressive properties. The collagen matrix is a material of choice to provide structural and microenvironmental support for SHED-to-dentin pulp tissue differentiation. Growth factors regulate cell proliferation, migration, and differentiation into specific phenotypes via signal-transduction pathways. This review provides current concepts and applications of the tissue engineering approach, especially SHEDs, in endodontic treatment.

Patterns of Post-Endodontic Restoration: A Nationwide Survey of Dentists in Turkey

Developments in materials and techniques, geographical locations, age, specialty, and affiliations of dental practitioners affect the preference of post-endodontic restoration. Thus, this survey aimed to evaluate the trends of dentists in Turkey in terms of post-endodontic restorations. An anonymous survey containing 10 questions regarding demographics, post-endodontic restoration patterns, and factors affecting restoration selection was electronically delivered to the dentists registered in the database of the Turkish Dental Association. The data were analyzed using by a chi-square test and ordinal logistic regression analysis. A total of 1093 surveys from 20,564 participants were collected with a response rate of 5.3%. Half of the participants (52%) preferred composite resins for post-endodontic restorations. Usage of posts was less prevalent amongst prosthodontists and dentists with clinical experience of more than 20 years compared to endodontists (p < 0.001) and dentists with clinical experience of less than 5 years (p = 0.004). More than half of the participants (56%) utilized fiber posts. Composite resins and fiber posts were the most common preferences in post-endodontic restoration. Endodontists had a higher tendency to use posts than prosthodontists and general dental practitioners.

Periodontal Tissue Reaction Consecutive Implantation of Endodontic Materials and Subsequent Integration of Complex Oral Rehabilitation Treatments

Oral rehabilitation is a main branch of dentistry focused on diagnosing the patient’s problem and creating a treatment plan to restore aesthetics, recondition morphologically all components, and recover the functionality of the oral cavity. Biological compatibility of the materials used has a major importance, due to the direct contact with essential tissues, such as the soft and hard tissue of the periodontium and the potential influence on the outcome of the treatment. The present material aims to assess the inflammatory response after subcutaneous implantation of three materials frequently used in endodontics (Mineral Trioxide Aggregate—MTA, DiaRoot BioAggregate, and Sealapex). The evaluation of the reparative tissue reaction after 7, 30, and 60 days, respectively, subsequent to in vivo implantation, was carried out through electron microscopy imaging. Moreover, evaluation of the dynamics of the osteogenesis process was an indicator for the maintenance of internal homeostasis in the context of complex intraoral rehabilitation treatments that include fixed prosthodontics correlated with the particular periodontal-aesthetic aspects and completed by cranio-mandibular repositioning. Our study showed increased absolute values of alkaline phosphatase in all material-implanted cases (more pronounced in MTA and Bio Aggregate), highlighting that this enzyme could be an effective indicator of bone formation, which takes place after the material implantation, with the most significant elevated values at 30 days postoperatively.

Post-Fatigue Fracture and Marginal Behavior of Endodontically Treated Teeth: Partial Crown vs. Full Crown vs. Endocrown vs. Fiber-Reinforced Resin Composite

Objectives: To investigate in vitro post-fatigue fracture behavior of endodontically treated molars having been differently restored. Methods: A total of 120 extracted human molars were used. A total of 120 specimens in 14 test groups and one control group (n = 8) were root canal treated. After postendodontic sealing and build-up (AdheSE Universal, SDR), additional MOD preparations were cut. Postendodontic restorations were: Direct restorations (Tetric EvoCeram BulkFill bonded with AdheSE Universal and EverX Posterior/Essentia bonded with G-Premio Bond; as filling (F) or direct partial crown (DPC) after reducing the cusps 2 mm; indirect adhesive restorations (partial crown/PC vs. full crown/FC): e.max CAD, Celtra Duo, both luted with Variolink Esthetic; indirect zirconia restorations (partial crown/PC vs. full crown/FC), luted with RelyX Unicem 2; indirect non-bonded cast gold restorations (partial crown/PC vs. full crown/FC; Degunorm), luted with Ketac Cem. Before and after 300,000 thermocycles (5/55 °C) and 1.2 Mio. A total of 100 N load cycles, replicas were analyzed under a SEM for marginal quality in enamel and dentin (where applicable) and finally, specimens were loaded until fracture. Results: In direct groups, there was no difference between RC and FRC in fracture strength (p > 0.05); however, direct partial crowns showed higher post-fatigue fracture resistance. Regarding marginal quality, intracoronal FRC restorations exhibited more gap-free margins in enamel than RC. In the indirect groups, there was no significant difference between partial and full crowns in any of the adhesively luted ceramic groups regarding post-fatigue fracture resistance. Zirconia partial crowns exhibited significantly lower marginal quality in enamel. Indirect groups performed significantly better than direct groups in fracture resistance. Within the indirect restorations, both cast gold groups and zirconia full crowns exhibited the highest fracture resistance being superior to control teeth. Significances: Within the limits of this in vitro investigation, it can be concluded that any kind of indirect restoration with cusp replacement is suitable for ETT restoration when a certain cavity extension is exceeded. All indirect restorations, i.e., endocrowns, partial crowns, and full crowns showed a promising performance after in vitro fatigue-loading.

Restorative Treatment Patterns After Root Canal Obturation in Public Hospitals in Riyadh

AIM

This study aims to describe the pattern of coronal restoration use among different dental specialties after root canal obturation in two governmental hospitals in Riyadh.

MATERIALS AND METHODS

Electronic dental records at King Abdul-Aziz Medical City and University Dental Hospital were reviewed. Teeth that underwent initial root canal treatment on a permanent tooth for obturation using gutta-percha between April 2019 and June 2019 were included. The collected data included the type of material used for coronal restoration after RCT, immediate post-space preparation, cotton pellet placement, the clinical title and specialty of the treating physician, and the center where treatment was performed. Excel was used for data collection. IBM SPSS was used for descriptive and interferential analyses.

RESULTS

A total of 763 patients were included in the study, in which the double seal technique was used in 56% of the patients, followed by Cavit, which was used in approximately 17% of the patients. Post space was prepared immediately after root canal treatment in 49 patients, and only 17 teeth received the final post, whereas post space was temporized for the rest of the prepared teeth and received the final post at the following visits. Significant relations were found between the type of material used and the clinical title of the treating physician and between the material of choice and the specialty of the dentist. The double seal was the technique of choice among endodontists and restorative dentists, whereas advanced general dentists frequently used Cavit. The least used materials were IRM, amalgam, and Ketac Silver.

CONCLUSION

The double seal technique was found to be the most commonly used method to achieve a coronal seal, followed by Cavit. Other materials used after RCT, in sequential order based on the frequency of use, were GIC, temporary crowns, resin composite, RMGIC, prefabricated post with composite buildup, IRM, amalgam, and Ketac Silver.

Survival of root filled teeth in general dentistry in a Swedish county: a 6-year follow-up study

OBJECTIVE

The purpose of the present study was to investigate the survival rate of root filled teeth in general dentistry in a Swedish county and to identify risk predictors with a significant influence on the survival rate.

MATERIALS AND METHODS

This is a retrospective 6-year follow-up study on 1642 recall patients with 1720 teeth root filled in general dentistry in the Public Dental Service in the county of Stockholm, Sweden. Background variables were collected from the database at baseline as potential predictors of tooth loss. The outcome variables were extraction during the 6-year follow-up period and the reason for the extraction. Stepwise Cox regression analysis was adopted in order to investigate the influence of the potential risk predictors on the risk for tooth extraction.

RESULTS

Nine percent of the root filled teeth were lost after 6 years. The most frequent reason for tooth loss was fracture and/or cracks (58%). The survival rate of the root filled teeth increased significantly for younger patients, root filled teeth with metal crowns (96%) and high quality of the root filling (93%). The survival rate differed significantly between tooth groups with the lowest survival for molars (83%). Composite fillings were significantly associated with lower quality of the root fillings.

CONCLUSIONS

Ninety-one percent of the root filled teeth survived after 6 years. The survival rate was significantly higher for teeth with root-fillings of high quality and metal crowns as well as for root filled teeth in younger patients. The lowest survival rate was found for molars.

The restoration of root filled teeth: a review of the clinical literature

Clinicians often face dilemmas regarding the most appropriate way to restore a tooth following root canal treatment. Whilst there is established consensus on the importance of the ferrule effect on the predictable restoration of root filled teeth, other factors, such as residual tooth volume, tooth location, number of proximal contacts, timing of the definitive restoration and the presence of cracks, have been reported to influence restoration and tooth survival. The continued evolution of dental materials and techniques, combined with a trend towards more conservative endodontic-restorative procedures, prompts re-evaluation of the scientific literature. The aim of this literature review was to provide an updated overview of the existing clinical literature relating to the restoration of root filled teeth. An electronic literature search of the PubMed, Ovid (via EMBASE) and MEDLINE (via EMBASE) databases up to July 2020 was performed to identify articles that related the survival of root filled teeth and/or restoration type. The following and other terms were searched: restoration, crown, onlay, root canal, root filled, post, clinical, survival, success. Wherever possible, only clinical studies were selected for the literature review. Full texts of the identified articles were independently screened by two reviewers according to pre-defined criteria. This review identifies the main clinical factors influencing the survival of teeth and restorations following root canal treatment in vivo and discusses the data related to specific restoration type on clinical survival.

Effect of Fiber Posts on Stress Distribution of Endodontically Treated Upper Premolars: Finite Element Analysis

By means of a finite element method (FEM), the present study evaluated the effect of fiber post (FP) placement on the stress distribution occurring in endodontically treated upper first premolars (UFPs) with mesial–occlusal–distal (MOD) nanohybrid composite restorations under subcritical static load. FEM models were created to simulate four different clinical situations involving endodontically treated UFPs with MOD cavities restored with one of the following: composite resin; composite and one FP in the palatal root; composite and one FP in the buccal root; or composite and two FPs. As control, the model of an intact UFP was included. A simulated load of 150 N was applied. Stress distribution was observed on each model surface, on the mid buccal–palatal plane, and on two horizontal planes (at cervical and root-furcation levels); the maximum Von Mises stress values were calculated. All analyses were replicated three times, using the mechanical parameters from three different nanohybrid resin composite restorative materials. In the presence of FPs, the maximum stress values recorded on dentin (in cervical and root-furcation areas) appeared slightly reduced, compared to the endodontically treated tooth restored with no post; in the same areas, the overall Von Mises maps revealed more favorable stress distributions. FPs in maxillary premolars with MOD cavities can lead to a positive redistribution of potentially dangerous stress concentrations away from the cervical and the root-furcation dentin.

Knowledge and practices of decontamination during root canal treatment by dentists in Jeddah

Background

The periapical area is healed through disinfection of root canal system and reduction of microbial infection after root canal.

Purpose

To assess the knowledge of dental practitioners about decontamination during root canal treatment and the techniques used in the government and private sectors of Jeddah, Saudi Arabia.

Methods

103 dental practitioners and interns from private and governmental sectors performing root canal treatment were included. To extract information, a questionnaire assessing knowledge and preferred techniques used in decontamination during root canals treatment was distributed. The association of variables was investigated using chi-square tests.

Results

The findings reflected that 82.5% of subjects used rubber dam for isolation with significantly more practitioner in the governmental (95.2%) as compared to the private sector (27.8%). Chelating agents were used by 13.3% of the practitioners in government sector and 1% practitioners in private sector (1%). The most commonly used irrigant was sodium hypochlorite. Calcium hydroxide was used more frequently in the governmental sector (29.8%) than in the private sector (11.8%), as intracanal medicament. Mechanical irrigation devices were used by 2.4% of practitioners in the governmental sector only.

Conclusions

There is a significant difference in practicing root canal disinfection techniques among dentists in governmental and private sectors but no difference in degree of knowledge.

An insight into patient's perceptions regarding root canal treatment: A questionnaire-based survey

Background:

A key setback of root canal treatment (RCT) is that most patients lack adequate knowledge about it. Understanding and identifying the factors that hinder or discourage patients from undergoing RCT is necessary to adequately address the issue. The review of literature shows that there is a paucity of data about the awareness and acceptance of RCT among patients in Indian population. Thus, the study was conducted with aim to assess patients’ awareness of RCT among patients reporting in Desh Bhagat Dental College and Hospital, Mandi Gobindgarh. By surveying the patients, a broad patient perspective on the issue was sought.

Materials and Methods:

This survey was conducted with the help of prestructured questionnaire consisting of 15 questions, distributed to random 450 patients coming to the outpatient department of Conservative dentistry and Endodontics in Desh Bhagat Dental College and Hospital. The completed questionnaires were then analyzed to assess patients’ experiences, concerns, and perceptions about RCT.

Results:

There is a lack of awareness among patients regarding RCT.

Conclusion:

It is important to create more awareness among the populace of our country about the significance of maintaining a healthy dentition and attendant sequel if not done so. More patients would consider having endodontic procedures if properly made aware of.

Development and characterization of a novel bulk-fill elastomeric temporary restorative composite

Objectives:

This study investigated the physical and mechanical properties, antibacterial effect and biocompatibility of novel elastomeric temporary resin-based filling materials (TFMs) containing zinc methacrylate (ZM).

Material and Methods:

Experimental TFMs were prepared by mixing the zinc methacrylate with monomer, co-monomer, photoinitiator and fillers. A ZM concentration of 0 (control), 0.5% (Z0.5); 1% (Z1), 2% (Z2), or 5% (ZM5) wt% was added to the TFMs. Fermit-N (F) was used for comparison with the experimental material. Microleakage, water sorption/solubility, degree of conversion, depth of cure, ultimate tensile strength, and hardness were determined and compared. A modified direct contact test (DCT) with Enterococcus faecalis and a Streptococcus mutans’ biofilm accumulation assay was carried out to evaluate the antimicrobial effect and cytotoxicity of the assay. Statistical comparisons were performed (α=5%).

Results:

The results showed that the physical and mechanical properties of the experimental TFMs with ZM are comparable with the properties of the commercial reference and some properties were improved, such as lower microleakage and water sorption, and higher ultimate tensile strength values. TFMs with ZM killed E. faecalis only after 1 h. Biofilm development of S. mutans was not affected by the inclusion of ZM in the experimental TFMs.

Conclusions:

The present findings suggest that the physical, mechanical and biological properties of the experimental TFMs with ZM are comparable with the properties of the commercial reference. However, some properties were improved, such as lower microleakage and water sorption, and higher ultimate tensile strength values.

Demographic factors in the choice of coronal restoration after root canal treatment in the Swedish adult population

BACKGROUND

After root canal treatment, a choice is made between different coronal restorations which in the long run could affect the survival of the tooth.

OBJECTIVE

To compare demographic characteristics between individuals choosing an indirect coronal restoration (crown, inlay/onlay) and individuals choosing other restorations after completion of a root filling.

METHODS

The cohort consisted of all root-filled upper first molars that were reported to the tax-funded Swedish Social Insurance Agency (SSIA) during 2009. After registration of the root filling, any subsequent coronal restorations within 2 years were identified. The crown group consisted of individuals registered with an indirect coronal restoration and the restoration group was the remaining individuals with a direct coronal restoration or lacking registration. Demographic data (gender, disposable income, age, educational level, civil status and country of birth) were received from Statistics Sweden or the SSIA. Statistical analyses included chi-square test, t test and logistic regression analysis. P < 0.05 was considered statistically significant.

RESULTS

An indirect coronal restoration was received by 7806 individuals (21.9%), and 27 886 individuals (78.1%) received a direct restoration. All demographic variables except gender differed significantly between groups. Logistic regression analysis found significant associations for all demographic variables and the registration of an indirect restoration except for country of birth and gender.

CONCLUSIONS

The identified demographic differences between individuals choosing to restore their newly root-filled teeth with an indirect restoration compared to those receiving other restorations may indicate that the tax-funded Swedish dental insurance fails to provide dental care on equal terms for Swedish citizens.

Complications of an Ageing Dentition Part 2: Restorative Management Options

This is the second-part of this three-part series. The first paper discussed the occlusal and cracked tooth aetiological factors which may be responsible for restoration failure. This paper will outline the restorative options for cracked and root canal-treated teeth. It will also briefly give an overview of some of the potential endodontic complications commonly associated with failed restorations. The third, and final, part of the series will provide an overview of the previous papers and conclude with a case report. Clinical relevance: Failure of amalgam restorations is a commonly encountered clinical problem in general practice and no one case presents in the same way. Therefore, a competent endodontic diagnosis and implementation of the most appropriate, minimally invasive restorative option requires an adequate knowledge of the current literature.

Complications of an Ageing Dentition Part 1: Occlusal Trauma and Cracked Teeth

A growing problem in dentistry is complications associated with failing amalgam restorations that have been in place for many years. At present, there is a wide variety of treatment options available in the clinician’s armamentarium when this situation arises, however, without the correct diagnosis, the prognosis for the tooth may quickly diminish, despite the clinician’s best efforts. A confusing array of symptoms and failures may confound even the most experienced dentist, which will inevitably lead to invasive and time consuming approaches in a desperate attempt to rectify the initial problem. This paper, the first part of a three-part series, discusses the possible aetiological factors responsible for restoration failure, including occlusal issues and cracks within the tooth structure. The second part of the series will focus on restorative options and root-treated teeth. The third, and final, part of the series will provide an overview of the previous papers and conclude with a case report. Clinical relevance: Failure of amalgam restorations is a commonly encountered clinical problem in general practice and no one case presents in the same way. A competent diagnosis regarding the occlusion and tooth structure, followed with implementation of the most appropriate, minimally invasive treatment option, requires an adequate knowledge of current literature.

Failure of single-unit restorations on root filled posterior teeth: a systematic review

This systematic review investigated the failure rate of conventional single-unit restorations in root filled posterior permanent teeth. Two reviewers independently applied eligibility criteria, extracted data and assessed the quality of the evidence of each included study according to the Cochrane Collaboration's procedures for randomized control trials (RCTs) and the STROBE criteria for observational studies. The MEDLINE (via Ovid), EMBASE (via Ovid), Cochrane Oral Health Group Trials Register and CENTRAL (via Cochrane Library) databases were searched electronically (January 1993 to week 1, February 2015). This was complemented by an additional hand search of selected journals and the references of relevant studies. Clinical studies published on root filled single-unit restorative treatments with a mean follow-up period of at least 3 years were selected. The outcome measured was clinical or radiological failure. Overall, the four RCTs and the single observational study included were of low and high quality, respectively. Therefore, a meta-analysis was not possible. The pooled mean failure rates were reported according to the type of treatment and remaining coronal tooth structure. The current evidence suggested that the failure rates of the treatments may depend on the amount of remaining tooth structure and type of treatment. Post-retained crowns were associated with the most favourable outcome in teeth with one to two remaining coronal tooth wall(s), whereas post-free crowns were superior when greater tooth structure was available. Restorations in teeth without ferrules had such a high rate of failure that other treatment options should be considered.

Carious Exposure versus Mechanical Exposure for MTA Pulpotomy in Primary Teeth

Introduction. The etiology of exposure determines pulpal response, making it crucial to distinguish between mechanical and carious exposure. This study clinically and radiographically evaluated the success of MTA pulpotomies conducted to treat carious and mechanical pulp exposure. Materials and Methods. This study was conducted with 50 mandibular primary molar teeth. Teeth were divided into 2 groups according to status of the exposure site, with teeth surrounded by carious dentin placed in a carious exposure group and those surrounded by sound dentin in a mechanical exposure group. MTA pulpotomies were performed for both groups. Treatment was followed up clinically and radiographically for 18 months. Results. Clinical and radiographic success rates at 18 months were 100% for both groups. Success rates did not vary significantly between the groups (p = 1.000). Pulp canal obliteration was only seen in the carious exposure group, observed in 2 teeth (8.3%). Conclusion. The long term success rates achieved in this study indicate that MTA can be used as a vital pulpotomy material for the long term success in primary teeth with either mechanical or carious exposure. The findings of the present study highlight the fact that treatment prognosis is dependent upon diagnosis and selection of the appropriate materials for treatment.

Annual review of selected scientific literature: Report of the committee on scientific investigation of the American Academy of Restorative Dentistry

STATEMENT OF PROBLEM

It is clear the contemporary dentist is confronted with a blizzard of information regarding materials and techniques from journal articles, advertisements, newsletters, the internet, and continuing education events. While some of that information is sound and helpful, much of it is misleading at best.

PURPOSE

This review identifies and discusses the most important scientific findings regarding outcomes of dental treatment to assist the practitioner in making evidence-based choices. This review was conducted to assist the busy dentist in keeping abreast of the latest scientific information regarding the clinical practice of dentistry.

MATERIAL AND METHODS

Each of the authors, who are considered experts in their disciplines, was asked to peruse the scientific literature published in 2015 in their discipline and review the articles for important information that may have an impact on treatment decisions. Comments on experimental methodology, statistical evaluation, and overall validity of the conclusions are included in many of the reviews.

RESULTS

The reviews are not meant to stand alone but are intended to inform the interested reader about what has been discovered in the past year. The readers are then invited to go to the source if they wish more detail.

CONCLUSIONS

Analysis of the scientific literature published in 2015 is divided into 7 sections, dental materials, periodontics, prosthodontics, occlusion and temporomandibular disorders, sleep-disordered breathing, cariology, and implant dentistry.

Effect of endodontic sealers on bond strength of restorative systems to primary tooth pulp chamber

Background/purpose

Although current literature suggests that root canal sealers affect the bonding ability of restorative systems to pulp chamber dentin of permanent teeth, primary teeth have not been investigated. This study intended to evaluate the microtensile bond strength (μTBS) of three restorative systems to pulp chamber dentin in primary teeth and to determine the effect of two different root canal sealers on the μTBS.

Materials and methods

Ninety primary molars were used in this study. The teeth were randomly divided into three main groups according to canal sealers: (1) control (without sealer); (2) Metapex; and (3) zinc-oxide eugenol. The main groups were further divided into three subgroups depending on the coronal restorative system: (1) compomer (Prime Bond NT + Dyract EXTRA); (2) composite (Clearfil Tri-S Bond + Clearfil Photo Posterior); and (3) resin-modified glass ionomer (Fuji II LC). After restoration, the buccal wall of the pulp chamber was sectioned to obtain sticks (1 mm × 1 mm). The μTBS was then measured. Data were analyzed with two-way analysis of variance, followed by a posthoc test. The interfacial morphology of the bonded space was evaluated using scanning electron microscopy.

Results

In the control group, a significant difference was observed only for the μTBS of the composite (P < 0.05). Compared with the control groups, Metapex and zinc-oxide eugenol significantly reduced the μTBS of restorative systems (P < 0.05).

Conclusion

Composite materials seemed to bond to pulp chamber dentin in primary teeth with a higher strength than compomer and resin-modified glass ionomer. Metapex and zinc-oxide eugenol canal filling materials reduced the bond strength of all three restorative systems.

Stability of endodontically treated teeth with differently invasive restorations: Adhesive vs. non-adhesive cusp stabilization

OBJECTIVES

Aim of the present study was to evaluate fracture strength of endodontically treated molars with different preparations/restorations after thermomechanical loading in vitro.

METHODS

264 extracted human third molars were used. Beside the control group, 256 teeth in 32 test groups (n=8) received root canal treatment (MTwo #40/.6) and root canal obturation with AH Plus and Guttapercha. After postendodontic sealing and build-up (Syntac, SDR), specimens were additionally prepared MO or MOD. Postendodontic restorations were: Direct restorations (Tetric EvoCeram Bulk Fill bonded with Syntac; as filling or direct partial crown (PC) after reducing the cusps 3mm; amalgam as filling or direct pin-retained partial crown (PC)), vs. indirect adhesive restorations (I: Inlay vs. PC; IPS Empress I/PC; Celtra Duo I/PC; e.max CAD I/PC; Lava Ultimate I/PC; Enamic I/PC - all inserted with Syntac/Variolink) vs. cemented cast gold I/PC. After 300,000 thermocycles (5/55°C) and 1.2 Mio. 100N load cycles, specimens were loaded until fracture.

RESULTS

Whereas IPS Empress showed no difference between I and PC (p>0.05), in all other groups PC were significantly more stable than fillings/inlays (p<0.05), this effect was more pronounced after MOD preparations. Cast gold PC exhibited the highest fracture strengths (p<0.05), inlays the lowest (p<0.05). IPS Empress was generally inferior to the other bonded materials under investigation (p<0.05) which as PC almost reached the level of control specimens. Amalgam fillings showed the worst outcome (p<0.05).

SIGNIFICANCES

Less invasive preparation designs were not beneficial for the stability of postendodontic restorations. Except for IPS Empress, PC were generally more successful in restabilization of weakened cusps after endodontic treatment and preparation. Cast gold PC remain the ultimate stabilization tool for ETT in terms of fracture resistance.