Intentional replantation (IR) is a suitable treatment option when nonsurgical retreatment and periradicular surgery are unfeasible. For successful IR, fracture-free safe extraction is crucial step. Recently, a new extraction method of atraumatic safe extraction (ASE) for IR has been introduced.

Ninety-six patients with the following conditions who underwent IR at the Department of Conservative Dentistry, Seoul National University Bundang Hospital, in 2010 were enrolled in this study: failed nonsurgical retreatment and periradicular surgery not recommended because of anatomical limitations or when rejected by the patient. Preoperative orthodontic extrusive force was applied for 2-3 weeks to increase mobility and periodontal ligament volume. A Physics Forceps was used for extraction and the success rate of ASE was assessed.

Ninety-six premolars and molars were treated by IR. The complete success rate (no crown and root fracture) was 93% (n = 89); the limited success rates because of partial root tip fracture and partial osteotomy were 2% (n = 2) and 5% (n = 5), respectively. The clinical and overall success rates of ASE were 95% and 100%, respectively; no failure was observed.

ASE can be regarded as a reproducible, predictable method of extraction for IR.

This retrospective study evaluated the therapeutic effects of the intentional replantation (IR) procedure performed on the maxillary and mandibular molars of 35 patients.

For the subjects, IR was performed due to difficulties in anatomically accessing the lesions and/or close proximity to the thick cortical bone, inferior alveolar nerve, or maxillary sinus, which rendered the ordinary periradicular surgery impossible. The patients' progress was followed for a year and up to 2 years and 4 months. The success of the procedure was evaluated in terms of clinical and radiographic success (%).

The results revealed the following: (a) 1 case (3%) of failed tooth extraction during IR; (b) 2 cases (6%) of extraction due to periodontal diseases and inflammatory root resorption; (c) 3 cases (9%) of normally functioning teeth in the oral cavity with minor mobility and apical root resorption, and; (d) 29 cases (82%) of normally functioning teeth without obvious problems.

IR was confirmed to be a reliably repeatable, predictable treatment option for those who cannot receive conventional periradicular surgery because of anatomic limitations or patient factors.

This study investigated the hypothesis that increasing light-curing time would leave the oxygen-inhibited layer (OIL) of the adhesive thinner, and in turn, result in lower shear bond strength (SBS) than those obtained by the routine curing procedures.

120 human extracted posterior teeth were randomly divided into three groups for bonding with three adhesives: All Bond 2®, One Step®, and Adper Prompt®. They were subsequently divided into four subgourps with different light-curing time (10, 20, 30 and 60 s). The assigned adhesives were applied on superficial occlusal dentin according to the manufacturer’s instructions and cured with one of the four curing times. Composite resin cylinder, 2.35 mm in diameter, were built on the cured adhesive and light-cured for 40 s. SBS were measured after 24 h from the bonding using a universal testing machine (crosshead speed 1.0 mm/min). The relative thickness of the OIL and the degree of conversion (DC) were determined from the adhesive on a slide glass using FT-NIR in an absorbance mode. Data were analysed with One-way ANOVA and Duncan’s multiple test (p < 0.05).

With increasing cure time, although there were no significant difference in th SBS of One-step and Adper Prompt (p > 0.05), those of All Bond 2 decreased significantly (p < 0.05). The relative thicknesses of the OIL on each adhesive were not affected by the cure time (p > 0.05). Although the DC of All-Bond 2 were statistically not different with increasing cure time (p > 0.05), those of One-Step and Adper Prompt showed an increasing trends with increasing cure time (p < 0.05).

Increasing light-curing time did not affect on the relative thickness of the OIL of the adhesives, and in turn, on the SBS to dentin.