Multidisciplinary treatment approach to restore deep horizontally fractured maxillary central incisor

Alternative treatment approach for anterior subgingival dental lesions: Forced eruption using attractive magnets

This article reports the use of a minimally invasive technique to address a challenging clinical problem in the esthetic zone. The clinical steps taken to achieve forced eruption by 1.5-2.0 mm of a maxillary central incisor that presented minimal clinical crown because of caries are described in detail. This subsequently allowed the successful placement of a crown. The tooth was extruded by forces generated between 2 neodymium-iron-boron magnets. One was affixed to the palatal surface of the tooth, and the other was embedded in a thermoformed splint. Weekly circumferential supracrestal fiberotomies were performed to enable extrusion without osseous migration. The extrusion was clinically and radiographically detectable after 6 weeks of magnetic force application. After an initial retention period of 8 weeks, the maxillary incisors were restored with lithium-disilicate ceramic veneers and crowns.

An in vitro study evaluating the effect of ferrule design on the fracture resistance of endodontically treated mandibular premolars after simulated crown lengthening or forced eruption methods

Background

The purpose of this study was to evaluate the effect of ferrule design on the fracture resistance of endodontically treated mandibular first premolars after simulated crown lengthening and orthodontic forced eruption methods restored with a fiber post-and-core system.

Methods

Forty extracted and endodontically treated mandibular first premolars were decoronated to create lingual-to-buccal oblique residual root models, with a 2.0 mm height of the lingual dentine wall coronal to the cemento-enamel junction, and the height of buccal surface at the cemento-enamel junction. The roots were divided randomly into five equal groups. The control group had undergone incomplete ferrule preparation in the cervical root, with 0.0 mm buccal and 2.0 mm lingual ferrule lengths (Group F0). Simulated surgical crown lengthening method provided ferrule preparation of 1.0 mm (Group CL/F1) and 2.0 mm (Group CL/F2) on the buccal surface, with ferrule lengths of 3.0 mm and 4.0 mm on the lingual surface, respectively. Simulated orthodontic forced eruption method provided ferrule preparation of 1.0 mm (Group OE/F1) and 2.0 mm (Group OE/F2) on the buccal surface and ferrule lengths of 3.0 mm and 4.0 mm on the lingual surface, respectively. After restoration with a glass fiber post-and-core system and a cast Co-Cr alloy crown, each specimen was embedded in an acrylic resin block to a height on the root 2.0 mm from the apical surface of the crown margin and loaded to fracture at a 135° angle to its long axis in a universal testing machine. Data were analyzed statistically using two-way ANOVA with Tukey HSD tests and Fisher’s test, with α = 0.05.

Results

Mean fracture loads (kN) for groups F0, CL/F1, CL/F2, OE/F1 and OE/F2 were as follows: 1.01 (S.D. = 0.26), 0.91 (0.29), 0.73 (0.19), 0.96 (0.25) and 0.76 (0.20), respectively. Two-way ANOVA revealed significant differences for the effect of ferrule lengths (P = 0.012) but no differences for the effect of cervical treatment methods (P = 0.699). The teeth with no buccal ferrule preparation in control group F0 had the highest fracture resistance. In contrast, the mean fracture loads for group CL/F2 with a 2.0-mm buccal and 4.0-mm lingual ferrule created by simulated crown lengthening method were lowest (P = 0.036).

Conclusions

Increased apically complete ferrule preparation resulted in decreased fracture resistance of endodontically treated mandibular first premolars, regardless of whether surgical crown lengthening or orthodontic forced eruption methods been used.

A modified endodontic post for three-dimensional root control in orthodontics

Interdisciplinary teamwork is a complex process in which different specialties work together to share expertise, knowledge, and skills to impact on patient care. This article describes the interdisciplinary management of a patient with a new innovative method of using endodontic post and core in orthodontics for three-dimensional root control of a root stump.

Dental extrusion with orthodontic miniscrew anchorage: a case report describing a modified method

In recent years, the skeletal anchorage through miniscrews has expanded the treatment options in orthodontics (Yamaguchi et al., 2012). We hereby present a modified method for tooth extrusion for cases where crown-lengthening surgery is contraindicated for aesthetic reasons. This modified method uses three orthodontic appliances: a mini-implant, an orthodontic wire, and a bracket. The aim of this case report was to increase the length of the clinical crown of a fractured tooth (tooth 23) by means of an orthodontic extrusion with the modified method of Roth and Diedrich.