ISSN: 0970-938X (Print) | 0976-1683 (Electronic)

Biomedical Research

An International Journal of Medical Sciences

- Biomedical Research (2016) Volume 27, Issue 1

Fracture resistance of prepared maxillary incisor teeth after different endodontic access cavity location.
Zeynep Ã
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Abstract

Objectives: The aim of this study was to evaluate the fracture resistance of prepared maxillary incisors with incisal access cavities and to compare it with conventional lingual access cavities. Materials and Methods: Freshly extracted maxillary central incisor teeth (n:45) were selected and prepared for full crown restorations. Then, they were divided into 3 groups: group 1, teeth with lingual access cavities (n: 15); group 2, teeth with incisal access cavities (n:15); and group 3, teeth without access cavities (n:15). Endodontic treatments were completed for group 1 and 2. All teeth were embedded in the self-curing acrylic resin. Specimens were subjected to fracture test and the maximum loads were recorded. Oneway ANOVA and Tukey’s HSD test were used for statistical analysis. Results: The mean fracture values of the group 3 (806.87 ± 174.80 N) were significantly higher than the group 1 (607.13 ± 131.14 N) and the group 2 (590.20 ± 237.29 N) (p<0.05). No statistically significant difference was detected between lingual and incisal access groups (p>0.05). Conclusion: The location of the endodontic access cavity of previously prepared maxillary incisors did not affect the fracture resistance. Clinical Relevance: An incisal access of previously prepared maxillary incisors may be preferred during endodontic treatment.

Keywords
Access cavity, Fracture resistance, Incisors, Preparation.

Introduction
The access cavity is one of the most important steps of the root canal treatment. An adequate access will facilitate cleaning, shaping and obturation of the root canal system in order to maximize the success of endodontic treatment [1]. The main reasons of the ideal access opening are to determine root canal orifices, obtain straight-line access to the apical part and make a conservative cavity preparation [2,3].
The traditional approach for maxillary anterior teeth is the lingual access that most commonly practiced [4-6]. The access cavity is located at the cingulum which has the shortest distance to the pulp chamber [5]. However, instrumentation of the root canals may be less effective with this approach, because a straight-line access to the apex is not allowed [4,7-9]. It has been also stated that traditional lingual access does not allow straight-line access to root canal systems of maxillary lateral incisors [4], maxillary central incisors and canines [7]. Then, the incisal access cavity was recommended in which a straight-line access to the apex would be allowed [4,7,10,11]. This access is a nearly universally acceptable technique [11], which facilitates proper cleaning, shaping and obturation of the tooth [3,7].
The design and location of access cavity affect the debridement of anterior teeth [4,7]. According to Davis, endodontic excavation of the coronal one third of the tooth should be as conservative as possible [12]. The loss of dental hard tissues is one of the most important reasons for fracture of endodontically treated teeth [13,14]. It is very important to preserve the lingual slope for anterior guidance because access cavity preparation may affect the risk of failure from direct contacts during anterior guidance for maxillary anterior teeth [15]. In addition, due to the greater dentin thickness on the lingual surface [16], the traditional lingual access cavity has a large preparation area that would weaken the clinical crown [10]. The purpose of this study was to determine the ideal location of endodontic access cavity in previously prepared maxillary incisor teeth in terms of fracture resistance.

Materials and Methods

The Yeditepe University Ethical Committee has independently reviewed and approved this study which has been conducted in full accordance with the World Medical Association Declaration of Helsinki. The authors obtained written consent from all participants involved in this study. Freshly extracted maxillary central incisor teeth with similar dimensions and shapes were selected for the study. The minimum sample size for the mean fracture strength parameter (?:219, SD:190) was statistically analyzed (power: 0.80, Ã

 

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