Sectional Impressions and ‘Every Other Tooth’ Technique in FPD

Abstract

The case report intends to present a combination technique used to restore lower six anterior teeth that was done as a part of full mouth rehabilitation.A 25-year-old female patient [Table/ Fig-1] reported to Department of Prosthodontics for replacement of missing teeth and complained of flat teeth and difficulty in chewing food. Intraoral examination revealed missing right mandibular first molar, severe attrition of the posterior teeth, flattening of canine tips, attrition of mandibular incisors, collapse of bite, temporomandibular joint click and overjet was 6 mm with a 5 mm overbite. There was no traumatic occlusion with respect to anterior teeth. The case was taken up for full mouth rehabilitation. A bite raising appliance was given to raise the bite by 3 mm. After a four month watch period of assessing patient acceptability and compliance, it was decided to start full mouth rehabilitation by first restoring the lower anterior teeth. Orthopantomograph (OPG) and full mouth Intra Oral Periapical Radiograph (IOPAR) revealed regressed pulp chambers and eliminated the need for root canal treatment. The clinical crown height of mandibular anterior teeth was less with attrition of incisors and considerable flattening of canines [Table/ Fig-2]. Full crowns were planned as they are stronger; provide good retention, better durability and aesthetics as compared to partial crowns and composite restoration. tooth preparation: As bite was raised [Table/ Fig-3] there was no need of reducing the incisal surfaces. All the axial surfaces of teeth #33, 32, 31, 41, 42, 43 were reduced by 1.5 mm with a distinct shoulder margin. As gingival sulci were shallow, equi-gingival margins were planned. Incisally, a functional cusp bevel was placed on the labio-incisal line angle. [Table/ Fig-4] shows tooth preparations of lower six anterior teeth. Gingival Displacement and Impression Making:Considering the root proximity with lower anterior teeth and to avoid strangulation of inter dental papillae, it was decided not to displace gingiva of all adjacent teeth at the same time. The 'every other tooth' technique was adopted. Gingival displacement of three alternate teeth was done followed by a sectional impression of the anterior segment. Two sectional impressions were required. Two custom sectional trays with a spacer thickness of two wax sheets and tissue stops on occlusal surfaces of teeth #34,44 were prepared. The trays were customized to cover mandibular teeth from tooth #34 to 44. A full arch custom special tray with two wax sheet spacer thickness and four tissue stops (on teeth #34,44,37,47) was made.Gingival displacement of teeth #33,31,42 followed by corresponding sectional impression was made [Table/ Fig-5]. Later, gingival displacement of teeth #32,41,43 followed by corresponding sectional impression was made [Table/ Fig-6]. Finally, a full arch impression without gingival displacement was made and kept aside [Table /Fig-7]. All the impressions were made using medium viscosity addition silicone impression material. Temporization...