Techniques for removing root canal posts: an vitro study / Técnicas para remoção de pinos intrarradiculares: um estudo in vitro

Objetivo: O objetivo deste estudo foi responder qual é a melhor técnica para remoção de pinos de fibra de vidro e pinos metálicos fundidos considerando tempo, preservação da estrutura dentária e custos. Métodos: Foi realizado um estudo in vitro, randomizado e cego. Sessenta dentes tratados endodonticamente foram randomizados em dois grupos de acordo com o tipo de pino. Uma segunda randomização foi realizada para cada tipo de técnica de remoção (ultrassom, broca ou combinada; n=10). One-way ANOVA foi usado para comparar o tempo de remoção do pino, teste t pareado comparou a quantidade de estrutura dentária removida e Kruskal Wallis seguido pelo teste post hoc de Mann-Whitney foram usados para análise de custo (P = 0,05). Resultados: Não houve diferença no tempo de remoção do pino considerando o tipo ou técnica do pino (P=0,630). A perda média de estrutura dentária na região cervical foi superior a 30% quando apenas uma ponta diamantada foi usada para remover pino de fibra de vidro (P<0,00001) e pino metálico fundido (P=0,008). Conclusão: De acordo com os resultados deste estudo, podemos concluir que a seleção da técnica de remoção dependerá da habilidade do operador, e sempre ocorrerá alguma perda de estrutura dentária, embora seja esperada uma perda maior quando apenas pontas diamantadas são usadas para este fim.(AU)

Objective: The aim of this study was to answer which is the best technique to removing glass fiber post and cast metal post considering time, preservation of tooth structure, and costs. Methods: An in vitro, randomized, blinded study was conducted. Sixty endodontically treated teeth were randomized into two groups according to post type. A second randomization was performed for each type of removal technique (ultrasound, drill, or combined; n=10). One-way ANOVA was used to compare the time to post removal, paired t-test compared the amount of tooth structure removed and Kruskal Wallis followed by post hoc Mann-Whitney test were used for cost analysis (P=0.05). Results: There was no difference in post removal time considering post type or technique (P=0.630). The average loss of tooth structure in the cervical region was greater than 30% when only a diamond bur was used to remove fiber glass post (P<0.00001) and cast metal post (P=0.008). Conclusion: According to the results of this study, we can conclude that the selection of the removal technique will depend on the skill of the operator, and some loss of tooth structure will always occur, although greater loss is expected when only diamond burs are used for this purpose.(AU)

Clinical follow-up evaluation of Dalbo®-Rotex® retention elements in the private practice

The aim of this retrospective study was to investigate the clinical outcome of Dalbo®-Rotex® retention elements in a private practice. The majority of the retention elements was fixed with self-adhesive composite cement, and in almost 40% the exposed root surface was additionally covered with composite. The success rate of 96.3% after 24 months in a total of 50 included patients (response rate 48.5%) demonstrated that a simple and cost-effective fixation of removable dentures using prefabricated, chair-side inserted retention elements is feasible. Maintenance care comprised single or repeated replacement and activation of the female part in 12.3% and 39.4% of the cases, respectively. Fractures were rare, occurring in 3.4% of the cases and more likely in patients with parafunctional habits. Frequent oral hygiene correlated with probing depths up to 3 mm at the maxi- mum, while the risk of greater probing depths associated with less frequent oral hygiene increased by a factor of 2.4. Patients' assessment of the parameters handling and wearing comfort, chewing ability and prosthesis retention was predominantly positive. Based on the findings of the study, covering of exposed dentin areas with composite resin and regular recall comprising professional cleaning, fluoride application and oral hygiene instruction are recommended.

Cost-effectiveness of Different Post-retained Restorations.

OBJECTIVES: Dentists can choose between metal and fiber post systems to provide post-retained restorations. The risk of tooth loss and other complications differs between different post systems, as do the initial treatment costs. We aimed to assess the cost-effectiveness of (1) cast metal (MC), (2) preformed metal (MP), (3) glass fiber (GF), and (4) carbon fiber (CF) post-retained restorations. METHODS: A mixed public-private payer's perspective within German healthcare was taken. Risks of complications were extracted from systematic reviews. Costs were estimated by using fee items and 2016 material costs. A Markov model was constructed to follow up an endodontically treated molar receiving a post-retained crown in an initially 50-year-old patient during his lifetime. Monte Carlo microsimulations were performed to assess lifetime costs and tooth retention time. RESULTS: MPs were least costly (€692€), retaining teeth for 26.7 years. GFs were more costly (€745€), retaining teeth for 27.6 years. MCs were minimally more effective but also more costly than GFs (€774€). CFs were less effective and most expensive (€825€, 26.7 years). For payers willing to invest more than €60€ per tooth retention year, GF was cost-effective. Payers willing to invest an additional €670€ found MC to be cost-effective. These findings were found robust in sensitivity analyses. CONCLUSIONS: For payers not willing to invest additional money for longer tooth retention, MP seemed most suitable to retain restorations. For payers with additional willingness to pay, GF seemed suitable, retaining teeth for longer. MC was only cost-effective under very high willingness to pay. CF is not recommendable on the basis of their cost-effectiveness.

Cost-effectiveness of endodontic molar retreatment compared with fixed partial dentures and single-tooth implant alternatives.

INTRODUCTION: One of the most challenging situations in dentistry is a failed root canal treatment case. Should a failed root canal-treated tooth be retreated nonsurgically or surgically, or should the tooth be extracted and replaced with an implant-supported restoration or fixed partial denture? These four treatment alternatives were compared from the perspective of cost-effectiveness on the basis of the current best available evidence. METHODS: The costs of the four major treatment modalities were calculated using the national fee averages from the 2009 American Dental Association survey of dental fees. The outcome data of all treatment modalities were retrieved from meta-analyses after electronic and manual searches were undertaken in the database from MEDLINE, Cochrane, ISI Web of Knowledge, and Scopus up to April 2010. The treatment strategy model was built and run with TreeAge decision analysis software (TreeAge Software, Inc, Williamstown, MA). RESULTS: Endodontic microsurgery was the most cost-effective approach followed by nonsurgical retreatment and crown, then extraction and fixed partial denture, and finally extraction and single implant-supported restoration. CONCLUSIONS: The cost-effectiveness analysis showed that endodontic microsurgery was the most cost-effective among all the treatment modalities for a failed endodontically treated first molar. A single implant-supported restoration, despite its high survival rate, was shown to be the least cost-effective treatment option based on current fees.

Evaluation of the cost-effectiveness of root canal treatment using conventional approaches versus replacement with an implant.

AIM: To evaluate the cost-effectiveness of root canal treatment for a maxillary incisor tooth with a pulp infection, in comparison with extraction and replacement with a bridge, denture or implant supported restoration. METHODOLOGY: A Markov model was built to simulate the lifetime path of restorations placed on the maxillary incisor following the initial treatment decision. It was assumed that the goal of treatment was the preservation of a fixed platform support for a crown without involving the adjacent teeth. Consequently, the model estimates the lifetime costs and the total longevity of tooth and implant supported crowns at the maxillary incisor site. The model considers the initial treatment decisions, and the various subsequent treatment decisions that might be taken if initial restorations fail. RESULTS: Root canal treatment extended the life of the tooth at an additional cost of pound5-8 per year of tooth life. Provision of orthograde re-treatment, if the root canal treatment fails returns further extension of the expected life of the tooth at a cost of pound12-15 per year. Surgical re-treatment is not cost-effective; it is cheaper, per year, to extend the life of the crown by replacement with a single implant restoration if orthograde endodontic treatment fails. CONCLUSION: Modelling the available clinical and cost data indicates that, root canal treatment is highly cost-effective as a first line intervention. Orthograde re-treatment is also cost-effective, if a root treatment subsequently fails, but surgical re-treatment is not. Implants may have a role as a third line intervention if re-treatment fails.

SEM observation of the bond integrity of fiber-reinforced composite posts cemented into root canals.

OBJECTIVES: To test the null hypothesis that continuity of resin cement/dentin interfaces is not affected by location along the root canal walls or water storage for 3 months when bonding fiber posts into root canals. METHODS: Fiber posts were luted to bovine incisors using four resinous luting systems: Multilink, Variolink II, Enforce Dual and Enforce PV. After cementation, roots were longitudinally sectioned and epoxy resin replicas were prepared for SEM analysis (baseline). The original halves were immersed in solvent, replicated and evaluated. After 3 months water storage and a second solvent immersion, a new set of replicas were made and analyzed. The ratio (%) between the length (mm) of available bonding interface and the actual extension of bonded cement/dentin interface was calculated. RESULTS: Significant lower percent values of bond integrity were found for Multilink (8.25%) and Variolink II (10.08%) when compared to Enforce Dual (25.11%) and Enforce PV (27.0%) at baseline analysis. The same trend was observed after immersion in solvent, with no significant changes. However, bond integrity was significantly reduced after 3 months water storage and a second solvent immersion to values below 5% (Multilink=3.31%, Variolink=1.87%, Enforce Dual=1.20%, and Enforce PV=0.75%). The majority of gaps were depicted at the apical and middle thirds at baseline and after immersion in solvent. After 3 months, gaps were also detected at the cervical third. SIGNIFICANCE: Bond integrity at the cement/dentin interface was surprisingly low after cementation of fiber posts to root canals with all resin cements. That was not significantly altered after immersion in solvent, but was further compromised after 3 months water storage. Gaps were mainly seen at middle and apical thirds throughout the experiment and extended to the cervical third after water storage for 3 months. Bond integrity of fiber posts luted to root canals was affected both by location and water storage.

Posts and cores: state of the art.

Post-and-core placement using prefabricated posts and composite resin is an everyday procedure in most general practices. Such posts are easily placed, strong, relatively inexpensive and predictable. The most popular techniques and materials have been described. It is anticipated that post-and-core use will continue to increase because of the current trend to retain natural teeth into the mature years of life.

Practical considerations and technical procedures for post-retained restorations.

Post-retained restorations are a practical and dependable treatment option for restoring teeth with insufficient coronal tooth structure. Manufactured post patterns combined with an effective clinical procedure will provide a simple, reliable, and economic method to produce restorations with a cast tapered post. The cast tapered post can be used for all clinical applications in which a post-retained restoration is indicated.