Bonding of enamel-dentin crown fractures with GLUMA and resin

Influence of Root Canal Posts on the Reattachment of Fragments to Endodontically Treated Fractured Incisors: An in vitro Experimental Comparison

OBJECTIVE

The aim of this study was to establish the benefits of inserting a fiberglass post when bonding tooth fragments after complicated coronal fractures.

METHODS

Thirty bovine incisors were randomly assigned to three groups: a control group of intact teeth (A), and two experimental groups (B and C). Coronal fragments were cut from the teeth in groups B and C, which then underwent root canal treatment, inserting posts in the teeth in group C. The coronal fragments were bonded to the teeth in both experimental groups using the same materials and technique, then the specimens were submitted to mechanical loading until fracture.

RESULTS

The specimens in the experimental groups had a lower resistance to mechanical loading than the intact teeth. The mean failure load was: 352.77 (SD ± 62.22) N in group A, 151.04 (SD ± 45.76) N in group B, and 168.61 (SD ± 33.59) N in group C. The difference between group A and the other two groups was statistically significant (analysis of variance test: p < 0.0001), whereas there was no statistically significant difference in the force needed to fracture the teeth in groups B and C (Tukey's test: p = 0.34). When the failure mode under loading was examined, the fractures in group C never involved new tooth substance beneath the adhesion interface, whereas in group B, this was only true in one in two cases.

CONCLUSIONS

Inserting a post does not significantly improve the strength of restored teeth, but it may result in a more favorable fracture mode.

CLINICAL SIGNIFICANCE

Within the limitations of this in vitro study, reattaching the fragment of a fractured tooth does not seem to restore the tooth to its original load resistance. The findings of this study indicate that inserting a fiberglass post for reinforcement purposes in fractured teeth undergoing root canal treatment is unable to significantly improve their load-bearing capacity by comparison with teeth repaired without inserting a post. However, the results of the present study suggest that inserting a post may result in a more favorable fracture mode in the event of further trauma.

Biologic Foundation Restoration: A Natural Post And Core For Management

Complicated crown fractures are a common outcome of dental trauma. Various treatment options are available for consideration. The preferred choice of treatment though, is determined by multiple factors associated with the nature of trauma itself. This case report highlights the management of a cervical crown fracture by modifying the clinical technique of an existing concept of the "Biologic Post and Core" and integrating it with current advances in adhesive technology, with an intention for preservation and reinforcement of residual tooth structure. The clinical success observed during subsequent patient recall has given reason for optimism in considering the employed method as a possible alternative to address this area of prosthetic concern.

A conservative single visit reattachment of fractured crown fragment

Injury of anterior teeth is a relatively common event that mainly affects children and adolescents. Dentists are confronted with managing dental trauma and restoring fractured teeth on a regular basis. Hence the techniques that speed and simplify the treatment, restore esthetics and improve long term success rate are considered of potential value. If an intact tooth fragment is present after trauma, immediate attachment of the incisal edge is a conservative yet, simple and aesthetic alternative. Fracture reattachment possesses challenging conservative and economically viable procedure within a single visit. The authors wuld report a case of fractured maxillary central incisor using fragment reattachment.

Alternative treatment procedure in the case of fractured abutment of adhesive bridge: a clinical report

In this case report, an alternative approach was presented for treatment of coronal fracture including pulp of maxillary central incisor, one of the abutments of an adhesive bridge, by using fiber post and tooth's own fractured component. The patient was referred to our clinic with the complaint of pain from the upper right central incisor and mobility of the adhesive bridge in maxillary anterior segment. It was realized that, the upper right central incisor, one of the abutments of the adhesive bridge, had been fractured at middle thirds of the crown including the pulp chamber. After dismounting the adhesive bridge and completion of the root canal treatment, a fiber post was placed into the fractured tooth. The fractured component, adherent to adhesive bridge retainer, was concorded to the fiber post. The whole structure was cemented with adhesive resin. A 1-mm-wide groove was made along the fracture line and restored with composite resin. The patient was evaluated clinically and radiographically at 12 and 30 months after the treatment.

CLINICAL SIGNIFICANCE

Adhesive cementation of fractured component by supporting the remaining tooth structure with a fiber post is an inexpensive and conservative treatment alternative when the fractured component is compatible with the remaining tooth structure in cases of tooth fractures including the pulp chamber at anterior segment.

Fracture strength of tooth fragment reattachments with postpone bevel and overcontour reconstruction

The purpose of this study was to test the actual resistance against fracture of a crown fragment fractured and reattached using three different techniques of preparation. Forty bovine incisors were randomly assigned into four groups of which the first was the control group. The elements of the three experimental groups were all cut at a fixed distance of 3 mm for the incisal margin on the buccal surface of the crown in a plane normal to the buccal surface itself, and subsequently re-bonded using an adhesive system. After the reattachment, on the teeth of group 2, a circumferential chamfer was performed along the fracture line; on the teeth of group 3 a groove called 'overcontour' was made also along the fracture line; the teeth in group 4 received a chamfer on the buccal surface and an overcontour on the lingual surface. Finally, all the elements were encompassed in chalk blocks and the models were mounted on the 858 Mini Bionix to perform a fatigue load test. A force was applied on the buccal surface of each tooth at 1.5 mm from the incisor margin, with a velocity of 1 mm min(-1), through the use of a steel prick. All the elements of groups 2, 3 and 4 demonstrated a lower resistance to fracture in comparison with the elements of the control group. The teeth of group 2 showed a resistance to fracture equal to 36.1% of the resistance of the elements in the control group; in group 3 the resistance was equal to 50.2%, while in group 4 the resistance reached 55.9%. The difference in resistance between group 3 and group 4 did not result statistically significant (P = 0.82). Reattachment of coronal fragments does not restore the resistance to fracture to an equal level of the intact teeth, in a static test. The different techniques of preparation significantly modify the resistance to the fracture of a re-bonded fragment. The technique of the circumferential chamfer produced results that were less favourable in terms of resistance against fracture.

Fracture resistance of re-attached coronal fragments--influence of different adhesive materials and bevel preparation

The purpose of this study was to investigate the fracture resistance of re-attached coronal fragments of teeth using different materials and tooth preparations. Seventy-two recently extracted bovine incisors were selected. Eight incisors were maintained without any preparation as a control group. The incisal third of the other teeth was sectioned using a diamond saw. In one group (n = 32), a 2-mm bevel was prepared, whereas in the second group no preparation was made (n = 32). The specimens (beveled and non-beveled) were divided in four groups (n = 8) and re-attached with the following materials: a dual-cured resin cement RelyX ARC (RX); a chemically cured composite Bisfil 2B (B2); a light-cured composite Z250 (Z2); and a one-bottle adhesive Single Bond (SB). The bevel region was restored with adhesive and composite. All materials were used according to manufacturer's directions. A light-curing unit was used to polymerize the materials. Specimens were stored in saline solution for 72 h. De-bonding procedures were performed in a testing machine with cross-head speed of 0.6 mm min(-1). The load was applied in the incisal third. The resistance to fracture for control group was 70 (7) kg. The fracture resistance for non-beveled and beveled specimens were: SB, 3.3 (2.4) and 17.0 (4.1); RX, 11.5 (3.0) and 16.3 (3.1); Z2, 14.4 (4.2) and 20.5 (1.7); and B2, 19.5 (3.5) and 32.5 (7.4) kg. Analysis of variance (anova) and Fisher's protected least significant difference (PLSD) test disclosed significant influence for materials and cavity designs (P = 0.001). The highest failure loads were obtained with the B2 group and then with the Z2 with either bevel or non-bevel. RX produced lower failure loads than the restorative composites. The lowest failure load was obtained with SB in the non-beveled group. No technique studied was able to attain the fracture resistance of the control group and both materials and tooth preparation influenced the fracture resistance.

Fractured teeth bonded with dentin adhesives with and without unfilled resin

Fractured incisors were restored by reattaching the fragment to the remaining tooth structure. For this purpose, seven dentin adhesive systems were used with and without an unfilled resin (Heliobond) and the strength of the restored teeth was tested at a cross-head speed of either 1 or 500 mm/min. The hypothesis was that the strength of the reattachment would be higher when an unfilled resin was used. The dentin adhesive systems were Prime & Bond NT (PB), Excite (EX), One-Step (OS), PQ1 (PQ), SingleBond (SB), Optibond Solo Plus (OS), and an experimental adhesive (GL). Statistical analysis revealed that with all adhesives except EX, a significantly greater mean fracture strength was achieved when the adhesives were used with the resin (Heliobond). Furthermore, with all adhesives except PB, there was a significantly lower mean fracture strength when tested at 500 mm/min than at 1 mm/min. All the tested adhesives except EX should be used with an unfilled resin when restoring fractured teeth by reattachment.

Incisal edge reattachment: indications for use and clinical technique

This article presents an overview of the evolution of the incisal edge reattachment procedure. Case reports are described of patients presenting with traumatised teeth in which the reattachment procedure was performed. A review is provided of present in vivo studies detailing long-term success rates in the clinical application of this procedure. Finally, a recommended technique for diagnosis and treatment is offered to improve success in this procedure which may benefit a significant segment of the paediatric and adolescent populations.

Pulp reactions to restoration of experimentally induced crown fractures

OBJECTIVES

Reattachment of the avulsed enamel-dentine coronal fragment to the remaining tooth structure has become an accepted clinical alternative to a resin composite build-up for the restoration of crown fractured teeth. Since little knowledge exists as to the pulpal response to this procedure, this study was designed to observe the condition of the pulp following experimentally induced crown fracture and restoration in monkeys.

METHODS

Experiments were conducted in eight young green Vervet monkeys (Cercopithecus aethiops). In all, 64 fractured incisors were investigated. Light microscopic examination of pulp tissue specimens was carried out after 3 months of observation.

RESULTS

The evaluation was restricted to specimens having a fracture plane within 2 mm of the pulp and no pulpal exposure. In general, pulp tissue was well preserved irrespective of the restorative procedure. Even if the restoration or the bonded tooth fragment had been lost during the follow-up period, the pulp generally remained in good condition. Inflammatory infiltrates where seen in only a few specimens and then as clusters of mononuclear leukocytes. Hard tissue repair was frequently observed and displayed various configurations from isolated hard tissue deposits to areas of extensive hard tissue repair in the coronal portion of the pulp. Pronounced hard tissue repair and occurrence of inflammatory cell infiltrates correlated with the presence of stainable bacteria on the fractured dentine surface.

CONCLUSIONS

In the absence of direct exposure, reparative dentine is a frequent feature of the pulp's response to crown fracture and restoration with composite or reattachment of the crown fragment with dentine bonding. These restorative procedures appear to ensure continued function of the underlying pulp.

Adhesive bonding of fragmented anterior teeth

This in vitro study investigated the fracture strengths of fractured incisors after reattachment to the remaining tooth structure, using either Gluma dentin-bonding agent together with 1 of 13 different experimental resins or 1 of the following dentin-bonding agents: Gluma+ (experimental modification of Gluma), Panavia21, ScotchBond1 (SingleBond), All-Bond2, Dentastic, SuperBond, Prime&Bond 2.1. No significant differences were found in the experiments with various experimental resins. The fracture strength of teeth rebonded with Gluma, All-Bond2, Dentastic, SuperBond or Prime&Bond 2.1 showed mean fracture strengths in the range of 8.7-11.2 MPa, which were significantly different in all cases from that of intact teeth (16.3 MPa). Teeth bonded with Gluma+, Panavia21 or ScotchBond1 (SingleBond) showed mean fracture strengths of 15.5, 14.6, and 14.2 MPa, respectively. These fracture strengths were not significantly different from that of intact teeth.

Esthetic, biologic and restorative considerations in coronal segment reattachment for a fractured tooth: a clinical report

Reattachment of a fractured clinical crown involving minimal invasion of the biologic width can be accomplished without conventional ostectomy and crown lengthening so that satisfactory esthetics can be achieved. Adhesive techniques sometimes in conjunction with traditional mechanical retention, such as a post, can be used to reattach the fractured segment. An esthetic result can be obtained with a minimal number of procedures and cost to the patient.

An in vitro investigation into the shear bond strengths of two dentine-bonding agents used in the reattachment of incisal edge fragments

This in vitro study investigated the shear bond strengths of sectioned bovine incisal edge fragments reattached using Gluma 2000 and Scotchbond 2. Teeth were sectioned 3 mm from the incisal edge using an Acutome with a 0.5 mm diamond wheel running at 90 degrees to the mesial or distal surface of the tooth. Twenty four incisal fragments were rebonded with each of the dentine bonding agents; a further 24 intact incisors were used as a control group. The control group required a mean fracture force of 940(+/- 144) N which was significantly greater (p < 0.01) than that required to fracture fragments rebonded using GLUMA 2000 (609 +/- 116) N and Scotchbond 2 (393 +/- 97) N. The mean force required to fracture incisal fragments rebonded with GLUMA 2000 was significantly greater (p < 0.01) than that required to fracture incisal fragments rebonded with Scotchbond 2.

Reattaching fractured tooth segments: an esthetic alternative

Reattaching fractured tooth segments offers an esthetic transitional restorative alternative to bonded composite and full crowns. The authors review this technique and demonstrate its application.

Treatment of crown fractured incisors with laminate veneer restorations. An experimental study

A method is described by which crown fractured incisors are restored with cast ceramic (Dicor) laminate veneers after initial treatment with either reattachment of the original crown fragment with a dentin bonding agent, with a composite resin build-up or no treatment (i.e. the veneer alone is used to restore the incisal edge). In order to elucidate the effect of the fragment/composite-tooth bonding interface on fracture strength of the restored teeth, the fracture strengths of the various treatment groups were compared to that of intact teeth supplied with Dicor laminate veneers. In an experimental investigation using central and lateral incisors from sheep, it was found that fracture strength (16.6 +/- 4.2 MPa) equal to that of intact incisors (16.1 +/- 2.6 MPa) could be achieved using laminate veneers made of porcelain on fractured teeth whose crown fragments were reattached using a dentin bonding agent (5). In the present investigation, using the same experimental model but using cast ceramic (Dicor) laminate veneers, the fracture strength of the restored incisors was significantly increased (21.0 +/- 3.7 MPa), exceeding that of intact teeth. The fracture strength of intact teeth was also exceeded in veneered incisors which were initially restored with a conventional composite resin build-up (20.2 +/- 5.6 MPa). However, the greatest fracture strength (28.2 +/- 8.9 MPa) was achieved when a Dicor laminate veneer alone was used to restore the fractured incisal edge.(ABSTRACT TRUNCATED AT 250 WORDS)

Reinforcement of bonded crown fractured incisors with porcelain veneers

A method is described by which porcelain laminate veneers are used to reinforce crown-fractured incisors which have been restored by reattachment of enamel-dentin fragments using enamel etching and a dentin bonding system. In an experimental model using sheep incisors, it was found that fracture strength equal to that of intact incisors could be achieved by employing this method. This is in contrast to fracture strengths of reattached enamel-dentin tooth fragments without porcelain laminates which were only 50% of intact incisors. It is suggested that porcelain laminate veneers may be used to supplement fragment bonding, thereby enhancing dental esthetics and function.

Enamel-dentin crown fractures bonded with various bonding agents

A method is described, by which the fracture strength of bonded, previously fractured incisors can be measured. The study employed incisors from sheep, which could be obtained in suitable numbers and with limited variation in size. The incisors were fractured parallel to the incisal edge. The mean fracture area +/- SD of central incisors was 8.45 +/- 0.89 mm2 and of lateral incisors 6.50 +/- 0.64 mm2. The enamel area constituted about 30% of the total fracture area. Acid etching of the enamel and bonding of the fractures with an unfilled resin yielded a fracture strength, which was approximately 38% of the fracture strength of fractured teeth restored with acid etching of enamel, Gluma treatment of dentin and bonding with the unfilled resin. Teeth restored in this way, but using the dentin bonding agent Tenure or Scotchbond2 instead of Gluma, exhibited mean fracture strengths which were not significantly different from that obtained when Gluma was employed as the bonding agent. The mean fracture strength by using one of the three bonding agents in combination with acid etching of enamel was about 8 MPa, which is approximately 50% of the fracture strength of intact teeth.

Treatment of traumatic dental injuries. Shift in strategy

A more conservative approach to the treatment of traumatic dental injuries has been made possible by knowledge concerning the pathogenesis of external root resorption, increased knowledge about wound healing processes in the pulp and periodontium, as well as by advances in restorative dentistry (reattachment of crown fragments with a dentin bonding system, the use of adhesive bridges, and advances in autotransplantation and implantation). However, a rethinking by the public, clinicians, and third-party payers is necessary for these procedures to gain wider acceptance. The present article describes the state of the art of treating dental trauma in the hope that these advances can become an accepted part of the dental trauma armamentarium and not merely scientific curiosities.