Long-term outcome of MTA apexification in teeth with open apices.

OBJECTIVE: This retrospective study aimed to collect information about the long-term outcome of apexification treatment with mineral trioxide aggregate (MTA) of teeth with open apices. METHOD AND MATERIALS: A total of 98 teeth in 79 patients (m:f = 1:1.3) who had completed endodontic apexification treatment with MTA between September 2005 and January 2014 at a university dental clinic were considered. Both initial treatments and retreatments of former root canal treatments other than apexification were included. All patients were invited for a standardized follow-up visit. Data regarding age, sex, tooth type, reason for treatment, detailed treatment protocol, clinical and radiographic findings, treatment quality, and outcome were also collected from the patients' records. Descriptive statistical analysis was performed. RESULTS: In the majority of cases, endodontic treatment was related to trauma with fracture (45/98, 45.9%) and luxation injuries (20/98; 20.4%), followed by unknown causes (12/98; 12.2%), retreatments (7/98; 7.1%), hypophosphatasia (7/98; 7.1%), and caries (1/98; 1%). In the beginning, the Periapical Index (PAI) showed pathologic findings with a PAI > 2 in approximately 50% of cases, while 25% presented with minor or an absence of findings. At the end of the observation period, more than 90% showed clinical-radiographic success, whereas eight teeth were associated with an elevated PAI. Only 5% of cases needed further dental treatment, such as root-end surgery or retreatment of the root canal treatment. CONCLUSION: Within the limits of this retrospective investigation, clinical and clinical-radiographic success of the apexification treatment appears to make this a good and reliable treatment option for teeth with open apices.

Longevity of occlusally-stressed restorations in posterior primary teeth.

PURPOSE: To compile a survey of the longevity and reasons for failure of stainless steel crowns, amalgam, glass-ionomer, composite and compomer restorations in stress-bearing cavities of primary molars. METHODS: This work reviewed the dental literature of 1971 up to July 2003 for longitudinal, controlled clinical studies and retrospective cross-sectional studies. Only studies investigating the clinical performance of restorations in primary teeth with an observation period of at least 2 years were included. Annual failure rates of stainless steel crowns, amalgam, glass-ionomer, composite and compomer restorations were determined and failure reasons were discussed. RESULTS: Annual failure rates in stress-bearing cavities of primary molars were determined to be: 0-14% for stainless steel crowns, 0-35.3% for amalgam restorations, 0-25.8% for glass-ionomer restorations, 2-29.1% for atraumatic restorative treatments, 0-15% for composite restorations, and 0-11 for compomer restorations. Main reasons for failure were secondary caries, marginal deficiencies, fracture, and wear.

4-year clinical performance and survival analysis of Class I and II compomer restorations in permanent teeth.

PURPOSE: To evaluate the 4-year clinical performance of the compomer Hytac in Class I and II cavities of permanent posterior teeth. METHODS: 53 compomer restorations were placed using the self-conditioning adhesive Hytac OSB (total bonding) without additional phosphoric acid-etching according to manufacturer's instructions. Restorations were rated (modified USPHS criteria) at baseline, after 6, 12, 18, 36 and 48 months in relation to tooth type (molar, premolar), size and class of cavities, isolation type (rubber dam, cotton rolls) and use of a calcium hydroxide liner. After 4 years, 39 restorations (73.6%) were available for examination. Statistical analysis was performed using Kaplan-Meier survival analysis with the logrank test and Fisher's exact test for the failure analysis. RESULTS: After 4 years, the success rate was 84.6%, six restorations failed (15.4%). The average annual failure rate was therefore 3.85%. Loss of marginal integrity was the main cause of restoration failure. The probability that a restoration would remain clinically acceptable after 4 years was calculated to be 89% (Kaplan-Meier). No significant performance differences could be found between any of the restoration groups.

Morphological characterization of the resin-dentin interface in primary teeth.

The effects of self-etching adhesives on primary teeth were evaluated. Reports in the literature suggest differences between the first and second dentition regarding the composition and the morphology and, therefore, a possible difference in the performance of dental adhesives. The purpose of this study was to evaluate the effects of self-etching adhesives on primary dentin. Eight dentin disks were obtained from the occlusal surface of primary molars. The disks were divided between four dental adhesives [Prompt L-PoP (LP), Clearfil SE BOND (SE), Etch&Prime 3.0 (EP) and Prime&Bond NT (PB) + H(3)PO(4) (Control) and "restored" with a composite (Pertac II)]. After sectioning, fixation and HMDS drying, specimens were polished and Field Emission SEM examinations were carried out. Clearly visible hybrid layer formation was found for PB, LP and EP. An undoubtedly detectable interdiffusion zone was not evident after the use of SE. A clearly visible adhesive layer was recognizable for PB, EP and SE, but not continuously detectable for LP. Debonded regions were observed for all systems evaluated, but distinct differences in the failure mode were detected. The evaluated dental adhesives did not generate completely sealed interfaces between the composite resin and the dentin of primary teeth in vitro.

Bond strength of self-etching adhesives to dental hard tissues.

Since most cavity preparations show not only areas of exposed enamel and superficial dentin but also of deep dentinal areas, it would be desirable to use a dental adhesive which can obtain equally good bond strength to these hard tissues. The objective of this study was to measure the bond strength of self-etching adhesives to enamel and superficial and deep dentin. Human molars were ground to expose a surface of enamel or superficial (2.0-2.5 mm distance to pulp) or deep dentin (0.5-1.0 mm), embedded in acrylic resin and assigned to three groups (total n=90). The adhesives tested were: Clearfil SE Bond (SE), Prompt L-Pop (LP), and Etch&Prime 3.0 (EP). After application of the adhesives, an inverted, truncated cone of composite (Pertac II, ESPE) was cured. After storage, specimens were debonded in tension at a cross-head speed of 0.5 mm/min. The median tensile bond strength values to enamel were SE 29.1 MPa, LP 22.4 MPa, and EP 21.5 MPa. The median bond strengths for superficial dentin were SE 27.3 MPa, LP 8.4 MPa, and EP 3.2 MPa. The median bond strengths for deep dentin were SE 20.2 MPa, LP 5.7 MPa, and EP 1.3 MPa. The adhesives tested bonded effectively to enamel, but only SE achieved promising bond strengths to superficial and deep dentin.