Endodontic Restoration Research Articles

Cumulative Effects of Successive Restorative Procedures on Anterior Crown Flexure : Intact versus Veneered Incisors

Objective When successive restorative procedures (e.g., porcelain veneers, interdental resin composite restorations, and endodontic treatment) are carried out on the same tooth, significant effects on crown flexure can be expected. Method and materials Dentin-bonded porcelain veneers (experimental group) were assessed in vitro using functional and cyclic thermal loads. They were compared to natural teeth (control group) with respect to 2 parameters: coronal flexure (investigated using experimental strain gauges) and morphology of the tooth-restoration interface (scanning electron microscopic evaluation). For both veneered and natural teeth, crown deformation was recorded at 5 sequential experimental steps: intact tooth (baseline), Class III cavities, Class III resin composite restorations, endodontic treatment, and endodontic restoration (without posts). Results No significant differences in crown flexure were found between natural and veneered incisors when compared across experimental steps. The main effect for experimental steps was highly significant. When averaged across all specimens (natural and veneered teeth), the endodontic treatment step resulted in the highest crown flexure (1.55x the baseline value). The unrestored Class III cavities and the endodontic restoration were next highest (1.30x and 1.28x the baseline value, respectively). The lowest crown flexures were found after restoration of the Class III cavities (1.13x the baseline value). No measurable microleakage or gaps were detected at the ceramic-resin, resin-enamel, or resin-dentin interfaces (Optibond FL, Kerr). Conclusion Each subsequent reduction in tooth structure resulted in a substantial increase in crown flexibility, even after restoration. Endodontic procedures were responsible for most of the loss in crown stiffness. Extensive proximal cutting and restorations seemed to minimally affect crown flexure. Porcelain veneers showed perfect biomimetic behavior, because cumulated restoration procedures had the same effect on natural and veneered incisors.

Prosthodontic treatment using vital and non vital submerged roots-two case reports.

Residual ridge resorption has been considered as an inevitable consequence after extraction of the teeth. There is a gradual loss of the alveolar bone due to the pattern of bone remodeling. In spite of the availability of newer treatment modalities like endodontic restoration and periodontic procedures for preservation of the remaining teeth they are not feasible for the patients in severe stages where restoration might not be possible. The only reliable method of preserving the remaining bone is by maintaining the functional health of the teeth. Over the years, many studies showed that roots which are fractured and left behind during extractions are retained into the alveolar bone with no evidence of pathosis. Over denture as a treatment option was developed in an effort to preserve the remaining alveolar bone by retaining the natural teeth or roots. In over denture treatment, the teeth selected as abutments are prone to caries and periodontal disease over a period of time, hence evolved the vital or non vital root submergence concept. After a thorough radiographic and clinical examination, few teeth without pathosis are retained that eventually are surgically submerged in the alveolar ridge. After healing, the over denture with reaining vital or non vital teeth preserve the integrity of the bone, making the treatment an effective and successfull preventive prosthodontic treatment.

Mechanical performance of endodontic restorations with prefabricated posts: sensitivity analysis of parameters with a 3D finite element model

Many studies have investigated the effect of different parameters of the endodontically restored tooth on its final strength, using in vitro tests and model simulations. However, the differences in the experimental set-up or modelling conditions and the limited number of parameters studied in each case prevent us from obtaining clear conclusions about the relative importance of each parameter. In this study, a validated 3D biomechanical model of the restored tooth was used for an exhaustive sensitivity analysis. The individual influence of 20 different parameters on the mechanical performance of an endodontic restoration with prefabricated posts was studied. The results bring up the remarkable importance of the loading angle on the final restoration strength. Flexural loads are more critical than compressive or tensile loads. Young's modulus of the post and its length and diameter are the most influential parameters for strength, whereas other parameters such as ferrule geometry or core and crown characteristics are less significant.

Post Endodontic Restoration: Are You Serious?

Post Endodontic Restoration: Are You Serious?

Morphological confocal laser scanning microscope evaluation of four different “etch and rinse^|^quot; adhesives in post endodontic restoration

The aim of this study was to perform a morphometric evaluation of the resin-root canal dentine interface of four "etch and rinse" adhesive systems. Forty human teeth were restored through a fiber post insertion using: Group 1: XP Bond adhesive; Group 2: Prime & Bond NT; Group 3: Surgi Prime Bond adhesive; Group 4: Scotchbond Multi-Purpose Plus. Two cross-sections (apical and coronal) were obtained and analyzed in morphological confocal laser scanning microscope. The numbers of resin tags (RT) and the thickness of the hybrid layer (HL) were evaluated. Quantitative variables were tested by a Shapiro-Wilk test. Parametric variables by an Anova test. Group 4 produced the thickest HL and Group 1 showed the thinnest. Considering RT, Group 1 produced the highest density, while Group 3 the lowest density. All the adhesives produced good results in terms of HL thickness and RT density.

Post Endodontic Restoration: Are You Serious?

After root canal obturation of sound posterior teeth, dentists are always in hurry of giving full crown. They are not serious in giving proper post endodontic restoration which results in fracture of tooth or restoration, if patient delays the full crown treatment. The inherent causes of failures are rarely evaluated. Thus, it was the purpose of this study to analyze the opinion of practicing dentist and after 24 months of clinical observation to present a logical approach to this subject as the final success of endodontic treatment is depend on the proper and timely coronal restoration.

Restoration Made Possible with Forced Orthodontic Eruption of Endodontically Treated Unrestorable Tooth: A Case Report

Post endodontic restoration in cases of grossly destructed teeth are difficult as the available tooth structure is less, margins are subgingival and of compromised prognosis because the restoration might encroach upon the periodontium affecting its status to deteriorate. Interdisciplinary approach using forced eruption or Orthodontic extrusion along with minimal surgical crown lengthening can give adequate supragingival tooth surface for proper restoration and protect its root support from getting violated. This is the case report of an unsalvageable tooth that is restored to satisfactory functional and esthetic restoration utilizing interdisciplinary approach.

Mechanical Properties of CAD/CAM Manufactured and Prefabricated Endodontic Posts

The aim of this study was to evaluate the stiffness, elastic limit and strength of CAD/CAM manufactured metal and zirconia posts in comparison to prefabricated zirconia and glass-fiber posts. Materials and methods: Four types of posts were investigated in this study (n=40). Prefabricated posts made of zirconia (Cosmopost) and glass-fiber reinforced composite (FRC Postec Plus), and Cr-Co (Magnum Lucens) and zirconia (Zirkonzahn) posts manufactured with a CAD/CAM system were used. Artificial root canals with similar diameters to those of the posts were drilled on a stainless steel metal block and the posts were cemented with a self-etch/self-adhesive dual cure resin cement (Totalcem). The posts were loaded in a universal testing device at an inclination of 135 degrees at a crosshead speed of 1mm/min. The force-deflection curves were recorded, and stiffness, elastic limit and strength of the posts were determined. Data were analyzed statistically using Mann Whitney U and Kruskall Wallis tests.Results: The difference between the strength, elastic limit and also stiffness values of the groups was statistically highly significant (p<0.01). CAD/CAM Cr-Co posts showed the highest values of strength, elastic limit and stiffness amongst all the posts investigated. CAD/CAM zirconia posts had the lowest values of strength, and FRC had the lowest values of elastic limit and stiffness. Cosmopost had higher values of elastic limit and stiffness compared to CAD/CAM zirconia posts.Conclusions: If an endodontic post restoration is required, functional load and aesthetics should be considered in addition to mechanical properties of the material selected.

A COMPARISON OF BOND STRENGTHS OF AMALGAM, COMPOSITE AND GLASS CERMET CORESWHEN RESTOREDWITH A PREFABRICATED PARALLEL POST – AN INVITRO STUDY

Dentists have come to realize that with proper endodontic therapy and adequate restoration, pulpless teeth can continue indefinitely as an integral part of the dental apparatus. And yet endodontic therapy should not be done on teeth that can not be restored. In this study 45 freshly extracted maxillary premolars were restored with prefabricated parallel post and subsequently restored with Amalgam, composite and Glass cermet. The teeth in each of the restoration groups were allocated to three different loading conditions, load at an angle of 10 0 , 45 0 and 90 0 to long axis of the specimen. It is observed that glass cermet core showed a mean failure load that was lower for all three loading conditions than those of Amalgam and composite cores. The aim of the study was to compare the bond strengths of Amalgam, composite and glass cermet cores restored with a pre-fabricated parallel post when subjected to simulated occlusal forces from varying angles.

Interpreting finite element results for brittle materials in endodontic restorations.

BackgroundFinite element simulation has been used in last years for analysing the biomechanical performance of post-core restorations in endodontics, but results of these simulations have been interpreted in most of the works using von Mises stress criterion. However, the validity of this failure criterion for brittle materials, which are present in these restorations, is questionable. The objective of the paper is to analyse how finite element results for brittle materials of endodontic restorations should be interpreted to obtain correct conclusions about the possible failure in the restoration.MethodsDifferent failure criteria (Von Mises, Rankine, Coulomb-Mohr, Modified Mohr and Christensen) and material strength data (diametral tensile strength and flexural strength) were considered in the study. Three finite element models (FEM) were developed to simulate an endodontic restoration and two typical material tests: diametral tensile test and flexural test.ResultsResults showed that the Christensen criterion predicts similar results as the Von Mises criterion for ductile components, while it predicts similar results to all other criteria for brittle components. The different criteria predict different failure points for the diametral tensile test, all of them under multi-axial stress states. All criteria except Von Mises predict failure for flexural test at the same point of the specimen, with this point under uniaxial tensile stress.ConclusionsFrom the results it is concluded that the Christensen criterion is recommended for FEM result interpretation in endodontic restorations and that the flexural test is recommended to estimate tensile strength instead of the diametral tensile test.

Post Endodontic Restoration of Severely Decayed Primary Dentition: A Challenge to Pediatric Dental Surgeon

ABSTRACT Dental caries is the single most common chronic childhood disease. In early childhood caries, there is early pulpal involvement and gross destruction of the maxillary anterior teeth. This leads to decreased masticatory efficiency, difficulty in speech, psychological problems due to compromised esthetics, development of abnormal tongue habits and subsequent malocclusion. The restoration of severely decayed primary incisors is often a procedure that presents a special challenge to dentists, particularly in an uncooperative child. This case presents the clinical sequence of rehabilitation of upper anterior primary teeth, where endodontic treatments were done chairside followed by the construction of root post using stainless steel and the fabrication of crowns composed of resin.

Gait analysis of a transfemoral amputee with a hydraulic polycentric knee prosthesis

This paper analyses the mechanical behaviour of a new reinforced anatomical post-systems (RAPS) for endodontic restoration. The composite restorative material (CRM) completely fills the root canal (as do the commonly used cast metal posts) and multiple prefabricated composite posts (PCPs) are employed as reinforcements. Numerical simulations based on 3D linearly elastic finite element models under parafunctional loads were performed in order to investigate the influence of the stiffness of the CRM and of the number of PCPs. Periodontal ligament effects were taken into account using a discretised anisotropic nonlinearly elastic spring system, and the full discrete model was validated by comparing the resulting stress fields with those obtained with conventional restorations (cast gold-alloy post, homogeneous anatomical post and cemented single PCP) and with the natural tooth. Analysis of the results shows that stresses at the cervical/middle region decrease as CRM stiffness increases and, for large and irregular root cavities that apical stress peaks disappear when multiple PCPs are used. Accordingly, from a mechanical point of view, an optimal RAPS will use multiple PCPs when CRM stiffness is equal to or at most twice that of the dentin. This restorative solution minimises stress differences with respect to the natural tooth, mechanical inhomogeneities, stress concentrations on healthy tissues, volumes subject to shrinkage phenomena, fatigue effects and risks of both root fracture and adhesive/cohesive interfacial failure.

Optimal mechanical design of anatomical post-systems for endodontic restoration

This paper analyses the mechanical behaviour of a new reinforced anatomical post-systems (RAPS) for endodontic restoration. The composite restorative material (CRM) completely fills the root canal (as do the commonly used cast metal posts) and multiple prefabricated composite posts (PCPs) are employed as reinforcements. Numerical simulations based on 3D linearly elastic finite element models under parafunctional loads were performed in order to investigate the influence of the stiffness of the CRM and of the number of PCPs. Periodontal ligament effects were taken into account using a discretised anisotropic nonlinearly elastic spring system, and the full discrete model was validated by comparing the resulting stress fields with those obtained with conventional restorations (cast gold-alloy post, homogeneous anatomical post and cemented single PCP) and with the natural tooth. Analysis of the results shows that stresses at the cervical/middle region decrease as CRM stiffness increases and, for large and irregular root cavities that apical stress peaks disappear when multiple PCPs are used. Accordingly, from a mechanical point of view, an optimal RAPS will use multiple PCPs when CRM stiffness is equal to or at most twice that of the dentin. This restorative solution minimises stress differences with respect to the natural tooth, mechanical inhomogeneities, stress concentrations on healthy tissues, volumes subject to shrinkage phenomena, fatigue effects and risks of both root fracture and adhesive/cohesive interfacial failure.

Mechanical behaviour of endodontic restorations with multiple prefabricated posts: A finite-element approach

This paper investigates some mechanical aspects of a new endodontic restoration technique, based on the idea that the root cavity can be more efficiently filled if multiple prefabricated composite posts (PCP) are employed. Multi-post technique increases bearing capacity and durability of endodontically treated teeth, as shown by numerical simulations performed through three-dimensional elastic finite-element static analyses of a lower premolar, constrained by a non-linearly elastic spring system representing the periodontal ligament, under several parafunctional loads. The influence of PCPs’ number, material and dimensions is investigated by comparison of the resulting stress fields with those obtained in cases of traditional restorations (cast metal post and cemented single-PCP) and natural tooth, highlighting the advantages of the proposed technique when standard restorative materials are considered. A risk-analysis of root-fracture and interface-failure shows that cast gold-alloy post produces high stress concentrations at post-dentin interface, whereas multi-post solution leads to a behaviour closer to the natural tooth's, exhibiting some advantages with respect to single-PCP restorations. As a matter of fact, whenever PCPs’ overall cross-section area increases, multi-post solution induces a significant reduction of stress levels into the residual dentin (and therefore the root-fracture-risk decreases) as well as of the expected polymerization shrinkage effects. Moreover, interfacial stress values in multi-post restorations can be higher than the single-PCP ones when carbon-fibre posts are considered. Nevertheless, the interfacial adhesive/cohesive failure-risk is certainly acceptable if glass-fibre posts are employed.

Dens invaginatus type II: case report with 2-year radiographic follow-up

Dens invaginatus is a malformation of teeth probably resulting from an infolding of the dental papilla during tooth development. Clinically, it is frequently characterized by unusual crown morphology. It is common to see peg- or barrel-shaped teeth. The present case describes dens invaginatus in a lateral maxillary incisor (Oehler type II) with a barrel-shaped crown of a 12-year-old female patient; endodontic treatment and adhesive restoration were performed. After two years the tooth showed no signs of pathosis.

Etiologi dan Pencegahan Kasus-Kasus Iatrogenik dalam Restorasi Perawatan Endodontikgahan Kasus-Kasus Iatrogenik dalam Perawatan Endodontik

As well as inadequate understanding of restoration procedure, previous studies showed that post endodontic restoration failures are mostly due to failure in determination of the indication. The purpose of post endodontic restoration is to preserve the functions of the tooth. To achieve that goal understanding of case selection, restoration procedure and operator skill are essential, so that iatrogenic case will be evaded.

An in vitro study of the effect endodontic access preparation and amalgam restoration have upon incisor crown retention

Endodontic access preparation leads to a significant reduction in crown retention. This study sought to determine whether this retention can be regained after access. Eighteen extracted human maxillary incisors had PFM crowns fabricated. Crowns were cemented, retention measured, recemented, access preparations cut, and retention once again measured. Then, crowns were recemented and accesses restored with dental amalgam and new retention measured. This format allowed each crown to be used as a control of itself. For crowns cemented with zinc phosphate cement and restored with amalgam, a 126% increase over original retention was measured. For crowns cemented with polycarboxylate cement and restored with amalgam, a 237% increase over original retention was measured. For crowns cemented with polycarboxylate cement and restored with amalgam, a 237% increase over original retention was measured. These results suggest that recementing crowns secondary to endodontic access and restoring the access with amalgam regains and even surpasses the original retention.

Endodontic therapy averting major surgery and avoiding keloid formation

Keloids and mandibular unfavorable fractures are reviewed. A case report of a patient with keloid diathesis, who had a mandibular unfavorable fracture, is presented. A grossly carious, abscessed first molar was in the line of fracture. This tooth was the only erupted tooth present in the proximal fragment. Endodontic therapy and restoration of normal contour enabled the surgeons to treat the fractured mandible by means of simple closed reduction. The endodontic treatment pre-empted a major surgical procedure under general anesthesia and also averted a skin incision which would have subsequently formed a disfiguring keloid.

Endodontic Therapy and Upper Canine Restoration Utilizing Dental Techniques

Endodontic Therapy and Upper Canine Restoration Utilizing Dental Techniques