Apexification is considered the treatment of choice for necrotic young permanent teeth with immature, open apices. This case study evaluates apexification completed on a previously treated permanent tooth of a 17-year old patient showing signs of symptomatic periradicular periodontitis. Apexification procedure was completed with the help of Er, Cr:YSGG laser and placement of Mineral Trioxide Aggregate (MTA) to allow for healing of periradicular tissues and disinfection of the canal system. Collagen matrix was used prior to placement of MTA to avoid extrusion of material in the periradicular tissues. One-year follow-up revealed significant healing of periradicular tissues and absence of any clinical signs and symptoms. This report provides an option of performing apexification procedure in combination with laser disinfection as opposed to past strategies which relied on chemical disinfection. This is aimed to increase long-term prognosis of the tooth.

Apexogenesis in young permanent teeth helps maintain the vitality of the pulp and aims at continued root dentin deposition. This allows continued root formation and apex closure leading to roots that are not weakened or likely to fracture due to thin root canal walls. This case report examines vital pulp therapy for a patient reporting signs and symptoms of irreversible pulpitis with her lower first mandibular molar. The tooth demonstrated incompletely formed root apices with normal periradicular tissues. Er,Cr:YSGG laser was used in conjunction with MTA to perform therapeutic pulpotomy and induce apexogenesis. The 17-month follow-up of the case demonstrated clinical and radiographic success with absence of any signs and symptoms, continued root end formation and increased root dentin thickness.

It is not unusual for a crack in the enamel to be found with proximal caries in the molar region and for caries to extend along the crack to below the gingival margin. However, when restoration by means of the indirect method is carried out for caries located on the proximal surface, an excessive amount of tooth material needs to be cut away and there is a danger that this can markedly reduce the strength of the remaining material. The direct method of restoration with composite resin is therefore desirable. Restoration of appropriate proximal contact and marginal conformity are essential with direct method restorations using composite resin, and there are a number of different methods. Among these, the method using a sectional matrix and separation ring may be optimal, but it cannot be used if the area of application is confined and caries extends below the gingival margin. Here, we report a two-stage method, in which the subgingival region is filled and then the proximal contact region is filled, through an actual clinical case.

Several minimally invasive periodontal surgical methods using microscopes have been reported, and minimally invasive periodontal surgery (MIPS) reported by Nagao in 2015 is a highly effective method for the treatment of intrabony defects. Here, the author reports a patient who relapsed after the first MIPS and subsequently underwent MIPS for a second time (Re-MIPS) in accordance with the original protocol. A good clinical outcome was obtained from Re-MIPS.

There are more and more reports on the use of microscopes in clinical dentistry, particularly in the field of endodontic treatment. For this reason, many clinicians see the microscope as something only used in endodontics. However, the author has used a microscope for almost all types of treatment, and here the clinical effectiveness of a microscope is shown in four cases: infiltration anesthesia, broken clasp denture repair, impacted tooth extraction, and pediatric endodontic therapy.

The long, cast post and core in the root canal of a maxillary anterior tooth can be efficiently removed using the Little Giant Post Puller, and by accurately cutting both the post core and the mesio-distal tooth under a surgical operating microscope. If the thickness of the residual tooth, which is the fulcrum for the legs of the Little Giant Post Puller, is at least 1.5 mm, the cast post and core can be removed without breaking the tooth root. With this method, such cores can be removed in a safe and minimally invasive manner, without cutting the dentin around the post. This method is effective for the retreatment of all such root canals, particularly those with an X-ray transmission image at the apex.

In this study, we investigated the effects of changing the core ratio of a passive instrument with a radial land using a rotary motion on changes in fatigue fracture and on centering ability in root canal shaping.

Passive instruments consisting of R-phase Ni-Ti files with one radial land, core ratios of 45%, 50%, 55%, 60%, 65%, and 70%, D1#25, and 0.06 taper were designed and subjected to torsional, bending, fatigue-fracture, screwing, and centering ability tests, with investigational comparison. The correlation with increasing core ratio was positive for torsional torque (r=0.9480) but negative for torsional angle (r=-0.8139), positive for bending torque (r=0.9689) but negative for both fatigue fracture (r=-0.8177) and screwing (r=-0.7746), and positive for centering ability displacement (r=0.6874).With a core ratio of 45%, file strength could not be maintained. Correlation with increasing core ratio was high negative for screwing. At core ratios of 50% to 65%, the time to fatigue fracture was long and free from root-canal screwing, indicating that root canal shaping can be performed safely at those core ratios.