Fracture resistance of endodontically restored, weakened incisors.

OBJECTIVES: To test the fracture strength of weakened bovine incisors endodontically treated with mineral trioxide aggregate (MTA), calcium phosphate bone cement (CPBC) or fibre reinforced composite (FRC) posts, and to evaluate the fracture mode. METHODS: Weakened bovine incisors (n = 75), standardized according to the dentinal wall thickness at the cervical area, were randomly assigned to one control group and three experimental groups. Unfilled teeth were assigned to group 1 (n = 20) and served as control group. Group 2 (n = 17) consisted of teeth filled with MTA. In group 3 (n = 18), the incisors were filled with CPBC and in group 4 (n = 20) with FRC posts. All specimens were subjected to load at a cross-head speed of 60 mm min(-1) until fracture occurred. The initial (IL) and final fracture (FL) loads (N) were recorded, and the failure mode among the different groups was evaluated. RESULTS: anova showed a statistically significant difference in fracture load among the groups. Tukey's test revealed a significant difference for the IL between the control group and the experimental groups with exception of the MTA group. The FL was not significantly different among the experimental groups. A high percentage of favourable fractures was seen in the FRC and CPBC groups. CONCLUSION: FRC posts and CPBC could be promising materials to strengthen non-vital structurally compromised teeth.

Educational background of Flemish dental practitioners and their perceptions of their management of dental trauma.

AIM: The aim of this study was to analyze whether any correlation existed between Flemish dental practitioner's educational background and their perceptions of their knowledge regarding emergency treatment for crown fractures and their actual expertise. METHODS: A questionnaire was distributed among 336 dental practitioners at six different locations in the country and completed prior to a lecture on dental traumatology. The response rate was 100%. The questionnaire consisted of three parts: the first part enquired about personal background, the second part requested a self-assessment of the practitioner's dental trauma education and treatment experience, and the third part tested the knowledge of the practitioner by asking for responses to different options for emergency treatment for dental trauma. RESULTS: Nearly 63% of the participants had more than 20 years of experience. Satisfaction about adequacy in basic education in dental traumatology was significantly related to the years as graduation to older graduates being less satisfied. This observation was not related to the additional education taken. Most frequently, uncomplicated crown fractures (42%) were seen more frequently than severe injuries. Concerning knowledge, a high result (67%) of incorrect answers was given for the treatment for injured immature permanent incisors. However, a high correlation was found between good knowledge of treatment and young professionals who graduated <10 years ago. Referring dental injuries for treatment was correlated with increasing level of difficulty. In the permanent dentition, however, complicated crown fractures (CCF) in immature teeth were not referred in many (66%) cases. CONCLUSION: It was observed that the knowledge of Flemish dental practitioners regarding emergency treatment for CCF is insufficient especially for the management of immature incisors.

Fracture resistance and reinforcement of immature roots with gutta percha, mineral trioxide aggregate and calcium phosphate bone cement: a standardized in vitro model.

Endodontic treatment of immature teeth is often complicated because of flaring root canals and open apices for which apexification is needed. Long-term prognosis for these teeth is surprisingly low because of cervical root fractures occurring after an impact of weak forces. In this study, an experimental model was developed to determine the fracture resistance of immature teeth and to test the hypothesis that endodontic materials succeed in reinforcing them. Compact and hollow bone cylinders from bovine femurs were used as standardized samples. In order to evaluate the experimental model, fracture resistance in both groups was evaluated by determining the ultimate force to fracture (UFF) under diametral tensile stress. Analysis of variance (ANOVA) revealed a statistically significant difference between the mean values of UFF for both groups, independently of the sampling location or subject. In a following setting, the hypothesis that obturation with gutta percha (GP), mineral trioxide aggregate (MTA), or calcium phosphate bone cement (CPBC) reinforces the hollow bone samples was investigated. Obturation resulted in a significant reinforcement for all materials, but the degree of reinforcement depended on the material. The experimental model appeared to be suitable for in vitro investigation of reinforcement and fracture resistance in a standardized way.

[Use of osteoconductive materials in pediatric dental medicine]. / Utilisation des matériaux ostéoconducteurs en médecine dentaire pédiatrique.

Osteoconductive materials are well known to have the ability to form a characteristic scaffold for bone replacement. The use of these agents is mostly described in periodontal procedures. The present study deals with the use of two different osteoconductive materials used for repairing bone defects following traumatic injuries. The materials used were Bio-Oss (Geistlich) an allogenic demineralised bone and Fisiograft (Ghimas) a synthetic co-polymer of polyglicolic and polylactic acid. These materials were used in five different clinical cases with the objective to compare their typical properties during application and to evaluate radiographically and clinically their healing ability. In three cases filling of the alveolus was performed after extraction of traumatised incisors as a consequence of root resorption or fracture; two patients suffered from periodontal defects. All cases were followed every three months for at least two years and maximum 6 years. Regarding the handling of the materials all products were well accepted. From our clinical experience all modalities are found to be suitable. After clinical and radiographical evaluation normal bone formation was found in all cases without any complaints nor clinical symptoms. These clinical findings support the use of osteoconductive agents in the field of Paediatric Dentistry in well-defined indications.