OBJECTIVE: To compare the clinical treatment efficiency of platelet-rich fibrin (PRF) assisted revascularization and traditional revascularization in immature permanent teeth. METHODS: Eighteen non-vital immature permanent teeth of sixteen patients which were diagnosed as necrotic pulpitis with (or without) periapical inflammations were treated with PRF assisted revascularization. Twenty-two teeth non-vital immature permanent teeth of twenty patients which were diagnosed as necrotic pulpitis with (or without) periapical inflammations were treated with traditional revascularization. All the cases were accorded with inclusive criteria and were treated at Pediatric Dentistry of Peking University School and Hospital of Stomatology. The cases were followed up clinically and radiographically at regular intervals. Clinical examinations and periapical radiographs were recorded and analyzed. Clinical success rate was evaluated based on the clinical and radiographic findings. The changes of root length, dentine wall thickness and apical foramen width of the teeth from the two groups were measured and compared according to the preoperative and by recalling the periapical radiographs. RESULTS: The cases were followed up for 6-16 months. Clinically, totally 17 out of the 18 teeth in PRF group and 21 out of the 22 teeth in traditional group were asymptomatic with no sensitivity to percussion or palpation. PRF group tended to be more effective than traditional group clinically without significant differences (P=0.446). Radiographically, 15 out of the 18 teeth in PRF group and 15 out of the 22 teeth in traditional group displayed that the roots developed, showing that root length and dentine wall thickness increased and apical foramen closed. There was a marked difference in dentine wall thickening in PRF group in comparison with traditional group (P=0.039). However, the changes of root length increasing (P=0.411) and apical foramen width closure (P=0.737) were comparable in both groups. The result in electric pulp test (P=0.517), root canal calcification (P=0.324) and crown discolor (P=0.386) were also comparable in the two groups. CONCLUSION PRF assisted revascularization and traditional revascularization in non-vital immature permanent teeth which were diagnosed as necrotic pulpitis with (or without) periapical inflammations resulted in similar clinical outcomes. Both methods showed good prognosis. PRF revascularization seemed to have better effect on dentine wall thickening than traditional method.
Child ; Dental Pulp/blood supply* ; Dentition, Permanent ; Humans ; Platelet-Rich Fibrin ; Root Canal Therapy ; Tooth Apex

OBJECTIVETo observe the process of pulp revitalization of immature permanent teeth after pulpectomy.

METHODSThirty-two single-rooted teeth with open apices from 4 Beagle dogs aged 4 months were included in the study. The pulpal tissues of 8 front teeth with single root of each dog were removed, and a blood clot was produced to the level of the cementoenamel junction followed by a double seal of mineral trioxide aggregate and composite resin. At day 7, 14, 21 and 28, respectively after operation, the dog was sacrificed, and then longitudinal paraffin sections were made for histologic investigation.

RESULTSAfter 7 days, about one thirth of the pulp chamber had an ingrowth of new tissue. After 14, 21, 28 days, there were more and more new tissue in the chamber. This new tissue consisted of well-organized and well-vascularized connective tissue. Hard tissue was too observed in the root canal. In some cases, the newly generated hard tissue even deposited against the canal dentinal walls.

CONCLUSIONSThe pulp of immature permanent teeth can revitalize after removal of the original pulp tissue under suitable conditions.

Animals ; Bone Regeneration ; Connective Tissue ; growth & development ; Dental Pulp ; blood supply ; growth & development ; Dental Pulp Cavity ; blood supply ; growth & development ; Dentition, Permanent ; Dogs ; Incisor ; blood supply ; growth & development ; Male ; Neovascularization, Physiologic ; physiology ; Pulpectomy

OBJECTIVETo observe the effect of revascularization for treatment of immature teeth with endodontic infection mediated by calcium hydroxide.

METHODSSeventeen pediatric patients with endodontic infections of the permanent teeth were treated with routine root canal and pulp cavity irrigation and disinfection followed by application of calcium hydroxide paste to the root canal orifice to induce revascularization. Another 17 patients received conventional apexification procedures to serve as the control group. The patients were followed up to observe the therapeutic effect of the treatments.

RESULTSIn the revascularization treatment group, 4 cases showed healed periapical lesions 6 to 18 months after the surgery with thickened root canal walls and closure of the apical foramen; in 10 cases, the periapical lesions healed 12 to 18 months postoperatively with lengthened root, thickened root canal wall, and narrowed apical foramen. One patient reported pain and swelling at 2 months, and 2 patients showed the formation of gum fistula and ceased development of the roots at 7 and 8 months. In the control group, the periapical lesions healed in 1 cases at 12 months postoperatively with apical foramen closure; in 11 cases, hard tissues formed in the root apex without obviously lengthened roots 6 to 8 months after the surgery; in 5 cases, no apical barrier formed even 12 to 18 months after the surgery. The overall effective rates were similar between the two groups (P>0.05).

CONCLUSIONSRevascularization by calcium hydroxide sealing can promote root development of immature permanent teeth with pulpitis or periradicular periodontitis.

Adolescent ; Calcium Hydroxide ; therapeutic use ; Child ; Dental Pulp ; blood supply ; Dental Pulp Diseases ; therapy ; Dentition, Permanent ; Guided Tissue Regeneration, Periodontal ; Humans ; Neovascularization, Physiologic ; drug effects ; Treatment Outcome

Revascularization of immature necrotic teeth is a reliable treatment alternative to conventional apexogenesis or apexification. In case 1, a 12-year-old boy had his necrotic, immature mandibular left second premolar treated with a revascularization technique. At a24-month follow-up, periapical radiolucency had disappeared and thickening of the root wall was observed. In cases 2 and 3, a10-year-old boy had his necrotic, immature, bilateral mandibular second premolars treated with the same modality. At 48-month(in case 2) and 42-month (in case 3) follow-ups, loss of periapical radiolucencies and increases in the root wall thickness were also observed.
Apexification ; Bicuspid ; blood supply ; diagnostic imaging ; pathology ; surgery ; Child ; Dental Papilla ; blood supply ; drug effects ; pathology ; Dental Pulp ; blood supply ; drug effects ; pathology ; Dental Pulp Necrosis ; pathology ; therapy ; Follow-Up Studies ; Humans ; Male ; Mandible ; Neovascularization, Physiologic ; Radiography ; Regeneration ; Root Canal Irrigants ; therapeutic use ; Root Canal Therapy ; methods ; Tooth Apex ; blood supply ; diagnostic imaging ; Tooth, Deciduous ; blood supply ; pathology ; Treatment Outcome

The aim of this article was to examine the research articles regarding biological and mechanical properties of cryopreserved teeth for potential use in tooth transplantation. A systematic review of literatures was performed by Pubmed searching with assigned key words from January 1, 1990 to June 8, 2009. All articles were examined for inclusion criteria. Secondary search was conducted by hand-search through references of included articles from primary search. A total of 24 articles were obtained from both primary and secondary search and used as fundamental articles in this review. Periodontal ligament tissues of cryopreserved teeth were able to maintain their biological properties resulted in a satisfactory healing of periodontium. Dental pulp tissues, however, may be compromised by limitation of permeability of cryopreservative agent into pulp cavity. Therefore, an endodontic treatment of transplanted cryopreserved teeth was recommended. Cryopreserved teeth had comparable mechanical properties to those of normal teeth. Importantly, the success of cryopreserved tooth transplantation treatment in orthodontic patients was reported. The cryopreserved teeth for tooth banking have a potential clinical application for treatment of missing teeth. Case selection, however, is critical for treatment success. More studies and data regarding masticatory function and periodontal healing of transplanted cryopreserved teeth are needed.
Cryopreservation ; methods ; Dental Enamel Permeability ; Dental Pulp ; blood supply ; cytology ; physiopathology ; Dentin Permeability ; Humans ; Periodontal Ligament ; physiology ; Tissue Banks ; Tooth ; transplantation

Formation of the periodontium begins following onset of tooth-root formation in a coordinated manner after birth. Dental follicle progenitor cells are thought to form the cementum, alveolar bone and Sharpey's fibers of the periodontal ligament (PDL). However, little is known about the regulatory morphogens that control differentiation and function of these progenitor cells, as well as the progenitor cells involved in crown and root formation. We investigated the role of bone morphogenetic protein-2 (Bmp2) in these processes by the conditional removal of the Bmp2 gene using the Sp7-Cre-EGFP mouse model. Sp7-Cre-EGFP first becomes active at E18 in the first molar, with robust Cre activity at postnatal day 0 (P0), followed by Cre activity in the second molar, which occurs after P0. There is robust Cre activity in the periodontium and third molars by 2 weeks of age. When the Bmp2 gene is removed from Sp7(+) (Osterix(+)) cells, major defects are noted in root, cellular cementum and periodontium formation. First, there are major cell autonomous defects in root-odontoblast terminal differentiation. Second, there are major alterations in formation of the PDLs and cellular cementum, correlated with decreased nuclear factor IC (Nfic), periostin and α-SMA(+) cells. Third, there is a failure to produce vascular endothelial growth factor A (VEGF-A) in the periodontium and the pulp leading to decreased formation of the microvascular and associated candidate stem cells in the Bmp2-cKO(Sp7-Cre-EGFP). Fourth, ameloblast function and enamel formation are indirectly altered in the Bmp2-cKO(Sp7-Cre-EGFP). These data demonstrate that the Bmp2 gene has complex roles in postnatal tooth development and periodontium formation.
Actins ; analysis ; Activating Transcription Factor 2 ; genetics ; Age Factors ; Ameloblasts ; pathology ; Amelogenesis ; genetics ; Animals ; Bone Morphogenetic Protein 2 ; genetics ; Cell Adhesion Molecules ; analysis ; Cell Differentiation ; genetics ; Cementogenesis ; genetics ; Dental Cementum ; pathology ; Dental Pulp ; blood supply ; Fluorescent Dyes ; Green Fluorescent Proteins ; Male ; Mice ; Mice, Knockout ; Microvessels ; pathology ; Molar ; growth & development ; Molar, Third ; growth & development ; NFI Transcription Factors ; analysis ; Odontoblasts ; pathology ; Odontogenesis ; genetics ; Periodontal Ligament ; growth & development ; Sp7 Transcription Factor ; Stem Cells ; physiology ; Tooth Root ; growth & development ; Transcription Factors ; genetics ; Vascular Endothelial Growth Factor A ; analysis ; Zinc Fingers ; genetics