Akiko Kato1, Koji Inagaki2,3, Michiya Utsumi4,2, Kazuo Kato5, Masaki Honda4. 1. Department of Oral Anatomy, School of Dentistry, Aichi Gakuin University, 1-100 Kusumoto-cho, Chikusa-ku, Nagoya, Aichi, 464-8650, Japan. a-kato@dpc.agu.ac.jp. 2. Department of Dental Hygiene, Aichi Gakuin University Junior College, Aichi, Japan. 3. Department of Periodontology, School of Dentistry, Aichi Gakuin University, Aichi, Japan. 4. Department of Oral Anatomy, School of Dentistry, Aichi Gakuin University, 1-100 Kusumoto-cho, Chikusa-ku, Nagoya, Aichi, 464-8650, Japan. 5. Department of Preventive Dentistry and Dental Public Health, School of Dentistry, Aichi Gakuin University, Aichi, Japan.
Abstract
PURPOSE: The aim of this study was to investigate root canal configurations in maxillary first and second molars from a Japanese population, as well as the relationship between the root canal number and root concavity depth, using micro-computed tomography. METHODS: Maxillary first (N = 74) and second (N = 70) molars from a Japanese population were used. Virtual horizontal sections were created, and the number of root canals and the degree of root concavity were measured. Mesiobuccal (MB) roots were categorized into Group 1 (with a single root canal) or Group 2 (with two or more root canals). The relationship between the root canal number and root concavity depth was evaluated using the Mann-Whitney U test. RESULTS: Approximately 51% and 35% of the MB roots in the three-rooted maxillary first and second molars, respectively, had two or more root canals. The depths of the root concavities in maxillary first molars differed significantly between Groups 1 and 2 at the mesial and distal sides of the MB root, in the section 2 mm apical to the furcation area (p < 0.05). CONCLUSIONS: A significant relationship between the number of root canals and the depth of root concavity in the MB root of the maxillary first molars was observed. Close clinical monitoring is needed during the removal of calculus and cleaning of the root surfaces of maxillary first molars: specifically, excessive removal of cementum and dentin should be avoided, particularly when the molar has already undergone root canal treatment.
PURPOSE: The aim of this study was to investigate root canal configurations in maxillary first and second molars from a Japanese population, as well as the relationship between the root canal number and root concavity depth, using micro-computed tomography. METHODS: Maxillary first (N = 74) and second (N = 70) molars from a Japanese population were used. Virtual horizontal sections were created, and the number of root canals and the degree of root concavity were measured. Mesiobuccal (MB) roots were categorized into Group 1 (with a single root canal) or Group 2 (with two or more root canals). The relationship between the root canal number and root concavity depth was evaluated using the Mann-Whitney U test. RESULTS: Approximately 51% and 35% of the MB roots in the three-rooted maxillary first and second molars, respectively, had two or more root canals. The depths of the root concavities in maxillary first molars differed significantly between Groups 1 and 2 at the mesial and distal sides of the MB root, in the section 2 mm apical to the furcation area (p < 0.05). CONCLUSIONS: A significant relationship between the number of root canals and the depth of root concavity in the MB root of the maxillary first molars was observed. Close clinical monitoring is needed during the removal of calculus and cleaning of the root surfaces of maxillary first molars: specifically, excessive removal of cementum and dentin should be avoided, particularly when the molar has already undergone root canal treatment.