Therefore, determining when to splint and selecting the most appropriate technique remains a difficult decision for clinicians. The aim of this study was to assess the biomechanical response in the anterior region of a mandible to bone loss and to different types of periodontal splints by measuring strains. Strains represent deformation, and thus indicate the biomechanical response of the mandible. Strains have previously been measured using strain gauges to analyse the biomechanical response of mandibular bone and tooth structures19 during masticatory loading in vivo18 and in cadavers with
natural teeth after implant insertion.20 Bone deformation has also been estimated indirectly by measuring strains on mandible replicas made of
epoxy resin21 or autopolymerized acrylic resin.19 In this study, it was hypothesized selleck that bone loss and splint type affect the strains in the mandible, and that the strain values depend on mandible surface (buccal or lingual), region (central or lateral incisor), and load level. Eighty mandibular human teeth (approved by the Federal University of Uberlândia Ethics Committee, protocol #112/06), extracted for periodontal or orthodontic treatment, were selected in this study: 20 central incisors, 20 lateral incisors, 20 canines and 20 first premolars (being half of the right side and half of the left side). Teeth of similar size were selected, where LEE011 mouse the buccolingual and mesiodistal widths had a maximum deviation of 10% from the mean. Soft tissue and calculus deposits were removed with a periodontal curette (Hu-Friedy, Chicago, IL, USA). The teeth were cleaned using a rubber cup and fine pumice water slurry and stored in 0.2% thymol solution (Pharmacia Biopharma Ltda, Uberlândia, Brazil). The teeth were randomly Coproporphyrinogen III oxidase divided into 10 groups. The teeth were stored in distilled water at 4 °C. To reproduce the
anatomy of the anterior mandible, an intact dentate human mandible was obtained from the Laboratory of Human Anatomy at Federal University of Uberlândia. A wax barrier (Wilson, Polidental Indústria e Comércio Ltda, Cotia, Brazil) was made around the anterior mandibular region up to the first molars (Fig. 1). A vinyl polysiloxane impression material (Aerojet, São Paulo, Brazil) was prepared according to the manufacturer’s instructions and inserted into the wax barrier. After 24 h the mandible was removed, leaving its impression in the vinyl polysiloxane mould. Melted wax was inserted into this mould to create a wax model. From the wax model, all teeth were removed at the level of the alveolar bone crest. An impression was made from the wax model using vinyl polysiloxane material. After 24 h the wax model was removed, creating a mould of the external anatomy of the anterior mandible. Ten wax (Epoxiglass, Diadema, SP, Brazil) replicas were made. Eight alveoli were created in the wax models. Before the teeth were inserted in the created alveoli, their roots were dipped into melted wax up to 2.