MTA versus Ca(OH)2 in apexification of non-vital immature permanent teeth: a randomized clinical trial comparison.

OBJECTIVES: The aim of this prospective randomized clinical trial was to compare mineral trioxide aggregate (MTA) with calcium hydroxide (CH) as materials for inducing root apex closure in immature necrotic permanent incisors. METHODS: The design of this study has been extensively described in the authors' previous report. Children (n = 30), aged from 6 to 18 years and presenting a non-vital permanent incisor, were treated. Half of the group received treatment using MTA, the other half with CH. At recall visits after 6 and 12 months, the presence or absence of a calcified apical barrier was assessed using clinical and radiographic examinations. The anonymised radiographs were evaluated by two independent investigators. Statistical analyses were performed using a Fischer's test (p < 0.05 was used as the threshold for statistical significance). RESULTS: Presence of a mineralized barrier was observed for 43.8% of the CH group and 64.7% of the MTA group at the 6-month examination. After 12 months, these figures were respectively 50 and 82.4% (p < 0.07). For both groups, pain and tenderness to percussion had disappeared at the 3-month examination. CONCLUSION: Neither material showed a statistically significant difference at the 6-month examination. At the 12-month examination, the MTA group displayed better results in terms of apical closure. In the CH group, four out of 15 teeth exhibited coronal or radicular fractures after 12 months. CLINICAL RELEVANCE: Apexification using MTA seems preferable to CH in order to early achieve the coronoradicular filling and to limit the risk of root fracture.

Outcome of endodontic treatments made by postgraduate students in the dental clinic of bretonneau hospital.

Objective. The objective of this retrospective study is double: (1) to assess the 1-4 years of outcome of endodontic treatment performed by postgraduate students in endodontics in the Dental Clinic of Bretonneau Hospital and (2) to examine outcome predictors. Method. 363 teeth in 296 patients were treated between 2007 and 2011. 183 patients (224 teeth) were lost during the followup. 113 patients were included in the study (recall: 38%), corresponding to 139 teeth of which 8 were extracted. 131 remaining teeth (36%) were examined clinically and radiographically. Apical periodontitis (AP) was absent (PAI = 1) or present (PAI ≥ 2). Outcome was classified as "healed," "healing," or "diseased". Results. The success rate was 92%. No failure was observed among the 23 initial endodontic treatments. Among the 108 retreated teeth, 80% were "healed" and 11% were "healing." An association was found between success rate and preoperative signs or symptoms (absent 95% versus present 83%), preoperative root filling density (inadequate 93% versus adequate 57%), but not between preoperative AP status and success. Conclusion. Outcomes in this retrospective study were similar to those previously reported. However, a larger sample size is needed to assess outcome predictors more precisely.

Management of internal root resorption on permanent teeth.

Internal root resorption (IRR) is a particular category of pulp disease characterized by the loss of dentine as a result of the action of clastic cells stimulated by pulpal inflammation. This review article explains the etiology, the prevalence of IRR, and, in addition to the clinical data, the contribution of the three-dimensional imaging (CBCT) to the diagnosis, the clinical decision, and the therapeutic management of IRR. The authors discussed the various therapeutic options including the orthograde or retrograde fillings of the root canal resorption area. Root canal treatment remains the treatment of choice of internal root resorption as it removes the granulation tissue and blood supply of the clastic cells. The authors describe with different clinical cases the modern endodontic techniques including optical aids, ultrasonic improvement of chemical debridement, and the use of alternative materials such as calcium silicate combined with thermoplastic filling (warm gutta-percha). In these conditions, the prognosis of the conservative treatment of internal resorptions, even if root walls are perforated, is good.

Mineral trioxyde aggregate versus calcium hydroxide in apexification of non vital immature teeth: study protocol for a randomized controlled trial.

BACKGROUND: Pulp necrosis is one of the main complications of dental trauma. When it happens on an immature tooth, pulp necrosis implies a lack of root maturation and apical closure. A therapy called apexification is required to induce the formation of a calcified apical barrier allowing a permanent and hermetic root filling. The aim of this prospective randomized clinical trial is to compare Mineral Trioxide Aggregate(MTA)with Calcium Hydroxide(CH)as materials used to induce root-end closure in necrotic permanent immature incisors. METHODS/DESIGN: This study, promoted by AP-HP, was approved by the ethics committee(CPP Paris Ile de France IV). 34 children aged from 6 to 18 years and presenting a non-vital permanent incisor are selected. Prior to treatment, an appropriate written consent has to be obtained from both parents and from children. Patients are then randomly assigned to either the MTA(experimental)or CH(control)groups. Recalls are performed after 3, 6 and 12 months to determine the presence or absence of a calcified apical barrier through the use of clinical and radiographic exams. Additional criteria such as clinical symptoms, apical radiolucencies, periapical index(PAI)are also noted. TRIAL REGISTRATION: ClinicalTrials.gov no. NCT00472173 (First inclusion: May 10, 2007; Last inclusion: April 23, 2009; study completed: April 15, 2010).

Caries risk and orthodontic treatment.

It is now established that orthodontic treatment increases the risk of carious lesions, with consequent harm to the patient and a high risk of compromising treatment outcome. This risk is related to the appliances, which increase the number of sites where plaque can accumulate as well as to changes in the bacterial flora and the age of the patient. A thorough evaluation of the risk of caries is therefore needed before any appliance is put in place and further evaluations should then be performed regularly throughout the course of treatment. In addition, preventive measures should be taken, involving first and foremost educating and motivating patients regarding the need for good oral hygiene. Prevention also implies adequate usage of the various sources of local fluoride administration, notably the application of fluoride-rich varnish. Other prophylactic measures such as using chlorhexidine varnish and sealing dental grooves are also recommended. Finally, the orthodontist can reduce to a minimum the use of items likely to retain dental plaque such as bands and elastomeric ties. The aim of this article is to suggest a specific diagnostic approach and to present the scientifically validated prevention measures, which need to be applied throughout orthodontic treatment.

Prevalence of apical periodontitis in root canal-treated teeth from an urban French population: influence of the quality of root canal fillings and coronal restorations.

This cross-sectional study determined the prevalence of apical periodontitis in 1035 root canal-treated teeth from adult French patients and investigated the influence of the quality of canal fillings and coronal restorations on the periradicular status. Periapical radiographs were used for analyses, and teeth were classified as healthy or diseased according to the periapical index scoring system. Overall, the prevalence of apical periodontitis in root canal-treated teeth was 33%. Only 19% of the teeth had endodontic treatments rated as adequate. The success rate (number of healthy teeth) for cases with adequate endodontic treatment was 91%, which was significantly higher when compared with teeth with inadequate treatment (61%). Teeth with adequate restorations had significantly decreased prevalence of apical periodontitis (29%) as compared with teeth with inadequate restorations (41%). The combination of adequate endodontic treatment and adequate restorations yielded the highest success rate (93.5%). The quality of the endodontic treatment was the most important factor for success, although the quality of the coronal restoration also influenced the treatment outcome.

Bioactive molecules and the future of pulp therapy.

Direct capping of bioactive molecules or implantation of these molecules in the pulp may induce the formation of reparative dentin and coronal or radicular pulp mineralization. In this review, we summarize what is known and/or assumed on the biological mechanisms of these therapies. We report on the effects which were obtained experimentally in rat maxillary molars by implantation of Bone Sialoprotein (BSP)/collagen pellets and Specific Amelogenin Gene Splice Products [A+4] and [A-4]) adsorbed on agarose beads. The effects were compared with those of BMP-7 (OP-1) and Ca(OH)2. Depending on the molecule that was used, we obtained either the formation of a dentin bridge, or the filling of the pulp in the mesial part of the coronal pulp chamber, or the total mineralization of the root canal. These molecules may provide new therapeutic tools in the next future in dentistry.

Unusual in vivo extensive corrosion of a low-silver amalgam restoration involving galvanic coupling: a case report.

The basic mechanism of dental amalgam corrosion has been thoroughly studied during the last 50 years by various experimental techniques, most often carried out in vitro. Electrochemical methods were extensively employed, and it was recognized that a gradual dealloying of the more electroactive components, Zn, Sn, and to a lesser extent Cu, contributed to change the surface composition. It is also well known that, in all circumstances, galvanic coupling threatens the longevity of the restoration. Among the patients examined at the hospital attached to the Department of Dental Surgery of the Paris 5 University, the authors observed, in a few exceptional circumstances of defective restorations, a release of liquid metal droplets in the surrounding tissue. These particles were identified as elemental mercury. This unexpected phenomenon was the result of the use of a low-silver-content alloy, combined with an enhanced corrosion process due to galvanic coupling with a silver alloy crown and brass screw-posts. In the described clinical case, the tooth, which had to be extracted, was axially sliced for observation by scanning electron microscopy coupled with elemental analysis by X-ray fluorescence energy dispersive spectroscopy. The observations showed a dramatic corrosion of the amalgam matrix with the formation of porosity even in the bulk of the material. Superposition of the element mappings proved (1) the electrochemical coupling of the amalgam with the silver-based crown, (2) the decalcification of the dentin, and (3) the formation of tin oxychloride precipitates in the matrix porosities and the interfacial gaps. These experimental results corroborate the corrosion mechanisms described hereupon. They support the current national and international recommendations for the dental amalgam formulation and for a rigorous professional practice.

Dental abnormalities in patients with familial hypophosphatemic vitamin D-resistant rickets: prevention by early treatment with 1-hydroxyvitamin D.

OBJECTIVE: To evaluate the dental effects of 1-hydroxylated vitamin D3 treatment in patients with familial hypophosphatemic vitamin D-resistant rickets. Study design Forty-eight children and adult patients were included in the study; 16 had received no treatment or phosphate supplements with vitamin D/25-(OH) D3 before puberty. The 32 younger ones had received phosphate supplements with 1alpha-(OH)D3 from infancy. All patients were clinically examined, and panoramic and periapical radiographs were made. Evaluations of decayed, missing, or filled teeth and decayed or filled teeth indexes and of pulp ratios allowed comparison with healthy age-matched control patients. RESULTS: Poor dental health and characteristic dental anomalies were found in the 16 older patients. In contrast, the 32 younger patients had a normal dental status as regards reference ranges in healthy age-matched populations, although they still showed prominent pulp horns on deciduous teeth and increased pulp area/tooth area ratios. CONCLUSIONS: This investigation shows the beneficial effects of 1alpha-(OH)D3 treatment on the dental status of vitamin D-resistant rickets patients and emphasizes the necessity of early treatment. Remaining defects may result from early exposure of odontoblasts and surrounding osteoblasts to hypophosphatemia, before the commencement of treatment, and/or from intrinsic cell disturbances linked to the genetic alteration(s).

Differential repair responses in the coronal and radicular areas of the exposed rat molar pulp induced by recombinant human bone morphogenetic protein 7 (osteogenic protein 1).

Bone morphogenetic protein 7 (BMP 7), also termed osteogenic protein 1, a member of the transforming growth-factor superfamily, was examined for its efficacy in inducing reparative dentinogenesis in the exposed pulps of rat molars. To determine if the reaction was dose-dependent, collagen pellets containing 1, 3 or 10 microgram of recombinant BMP 7 were inserted in intentionally perforated pulps (10-12 pulps per group) in the deepest part of half-moon class V-like cavities cut in the mesial aspect of upper first molars. As controls, the collagen carrier (CC group) alone and calcium hydroxide (Ca group) were used as capping agents. All cavities were then restored with a glass-ionomer cement. Half of the animals were killed after 8 days and the other half after 28 days, by intracardiac perfusion of fixative. The molars were processed for histological evaluation by light microscopy. No difference in effect could be detected between the three concentrations of BMP 7 groups at either time interval. After 8 days, all groups showed varying inflammation, from mild of severe, and the Ca group demonstrated early formation of a reparative dentine bridge. At 28 days the CC group displayed irregular osteodentine formation, leaving some unmineralized areas at the exposure site and interglobular unmineralized areas containing pulp remnants. In the Ca-treated pulps, the initial formation of thick reparative osteodentine bridges that sealed more or less completely the pulp perforation was followed, in the deeper part, by irregular tubular dentine. In most BMP 7-treated specimens, the initial inflammation has resolved at 8 days and at 28 days heterogeneous mineralization or osteodentine filled the mesial coronal pulp. They also had complete filling of the radicular pulp by homogenous mineralization in the mesial root; this reaction was found in 11 teeth in the BMP 7 group, one tooth in the CC group an none of the Ca group. These results emphasize the biological differences the coronal and radicular parts of the pulp, and the potential of bioactive molecules such as BMP 7 to provide an a alternative conventional endodontic treatments.