Continued root maturation despite persistent apical periodontitis of immature permanent teeth after failed regenerative endodontic therapy.

Three immature permanent teeth with pulp necrosis and apical periodontitis were treated with regenerative endodontic therapy (RET), which included root canal disinfection with sodium hypochlorite irrigation, intra-canal medication with calcium hydroxide paste, 17% EDTA rinse, induction of periapical bleeding into the canal, collagen matrix and MTA coronal seal, and composite resin restoration of access cavities. After different periods of follow-up, it was observed that continued root maturation, especially apical closure occurred despite persistent apical periodontitis of immature permanent teeth after failed RET. This finding is of interest as the secondary goal of further root maturation occurred despite failure of the primary goal of elimination of clinical symptom/sign and periapical inflammation. The possible biological mechanisms that could allow for further root maturation to occur in spite of persistent root canal infection of immature permanent teeth are discussed. Based on these observations, the biology of wound healing of immature permanent teeth after injury is not fully understood and should be further investigated. This case report demonstrates that whilst further root maturation is considered a successful outcome for teeth treated with RET, the primary objective must be the resolution of the signs and symptoms of apical periodontitis.

Regenerative Endodontic Treatment of an Immature Necrotic Molar with Arrested Root Development by Using Recombinant Human Platelet-derived Growth Factor: A Case Report.

Regenerative endodontic treatment has provided a treatment option that aims to allow root maturation. The present report describes the regenerative endodontic treatment of a necrotic, immature molar by using recombinant human platelet-derived growth factor (rhPDGF-BB) and shows the continued root maturation in the tooth with arrested root development. A regenerative endodontic procedure that used a growth factor was performed for a necrotic molar with arrested root formation in a 20-year-old patient. Thorough disinfection by using mechanical instrumentation and copious irrigation of antimicrobial agents as well as intracanal medication with calcium hydroxide was performed throughout the first 2 appointments. At the third appointment, the root canals were irrigated with an antimicrobial solution and 17% EDTA, and bleeding was evoked by passing sterile paper points beyond the apex in each canal. Small pieces of a collagen membrane saturated with rhPDGF-BB solution from GEM 21S were packed into each canal. Mineral trioxide aggregate was placed, and Cavit and composite resin were used to restore the tooth. Complete root maturation and resolution of a periapical radiolucency were observed at the 15-month follow-up. The present report presents a regenerative endodontic procedure that uses rhPDGF-BB for a necrotic molar with arrested root development. The finding of continued root development in the present case suggests that regenerative endodontic treatment may be able to resume the root maturation process in teeth with arrested root formation. Further clinical studies are required to investigate the efficacy of rhPDGF-BB in regenerative endodontic treatment.

Regenerative endodontic treatment of permanent teeth after completion of root development: a report of 2 cases.

INTRODUCTION: Clinical regenerative endodontic treatment has been focused on immature necrotic teeth, but it should be extended to mature teeth as an alternative to conventional endodontic treatment. There have been no clinical reports to attempt to revascularize pulp in the entire root canals of mature necrotic teeth. The present report describes the treatment of mature, necrotic, permanent incisors with apical periodontitis by using regenerative endodontic therapy. METHODS: In this case report, modified regenerative endodontic procedures were used to enhance the probability of pulp revasuclarization in mature necrotic teeth. At the first appointment, the root canals were mechanically instrumented to the apices with a large apical size by using the step-back technique and irrigated copiously with antimicrobial solution. Intracanal medicaments (calcium hydroxide or ciprofloxacin) were placed in the root canals. At the following appointment, the root canals were irrigated with antimicrobial solution, and bleeding was induced into the root canals by passing hand files beyond apices. Collagen membranes were placed in the canals as a matrix against which mineral trioxide aggregate was placed. Glass ionomer was used to restore the teeth. The resolution of apical radiolucency and regression of clinical signs and symptoms were observed at recall appointments. CONCLUSIONS: The present report presents modified regenerative endodontic procedures for mature necrotic permanent teeth. Further clinical studies with a large number of cases are needed to investigate the outcome of regenerative endodontic therapy for mature necrotic teeth.