title: Theoretical distribution of gutta-percha within root canals filled using cold lateral compaction based on numeric calculus.
abstract: This study aimed to present a new method based on numeric calculus to provide data on the theoretical volume ratio of voids when using the cold lateral compaction technique in canals with various diameters and tapers. Twenty-one simulated mathematical root canal models were created with different tapers and sizes of apical diameter, and were filled with defined sizes of standardized accessory gutta-percha cones. The areas of each master and accessory gutta-percha cone as well as the depth of their insertion into the canals were determined mathematically in Microsoft Excel. When the first accessory gutta-percha cone had been positioned, the residual area of void was measured. The areas of the residual voids were then measured repeatedly upon insertion of additional accessary cones until no more could be inserted in the canal. The volume ratio of voids was calculated through measurement of the volume of the root canal and mass of gutta-percha cones. The theoretical volume ratio of voids was influenced by the taper of canal, the size of apical preparation and the size of accessory gutta-percha cones. Greater apical preparation size and larger taper together with the use of smaller accessory cones reduced the volume ratio of voids in the apical third. The mathematical model provided a precise method to determine the theoretical volume ratio of voids in root-filled canals when using cold lateral compaction.
authors.affiliation: State Key Laboratory of Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory of Oral Biomedicine of Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, 430079, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Min
authors.affiliation: State Key Laboratory of Oral Diseases, West China College & Hospital of Stomatology, Sichuan University, Chengdu, 610041, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Song
authors.affiliation: State Key Laboratory of Oral Diseases, West China College & Hospital of Stomatology, Sichuan University, Chengdu, 610041, China. gaoyuan@scu.edu.cn.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Gao
authors.affiliation: School of Dentistry, College of Biomedical and Life Sciences, Cardiff University, Cardiff, UK.
authors.forename: Paul M H
authors.initials: PMH
authors.lastname: Dummer
mesh_terms: D003786:Dental Pulp Cavity / Q000187:drug effects*; D004853:Epoxy Resins / Q000627:therapeutic use; D006171:Gutta-Percha / Q000627:therapeutic use*; D006801:Humans; D008962:Models, Theoretical; D012387:Root Canal Filling Materials / Q000627:therapeutic use; D018915:Root Canal Preparation / Q000379:methods*; D013499:Surface Properties; D014025:Titanium / Q000627:therapeutic use
chemical_list: D004853:Epoxy Resins; D012387:Root Canal Filling Materials; D006171:Gutta-Percha; D014025:Titanium
keywords: apical preparation; gutta-percha; lateral compaction; volume ratio of void