Influence of enamel matrix derivative (Emdogain((R))) and sodium fluoride on the healing process in delayed tooth replantation: histologic and histometric analysis in rats

Although it has already been shown that enamel matrix derivative (Emdogain((R))) promotes periodontal regeneration in the treatment of intrabony periodontal defects, there is little information concerning its regenerative capacity in cases of delayed tooth replantation. To evaluate the alterations in the periodontal healing of replanted teeth after use of Emdogain((R)), the central incisors of 24 Wistar rats (Rattus norvegicus albinus) were extracted and left on the bench for 6 h. Thereafter, the dental papilla and the enamel organ of each tooth were sectioned for pulp removal by a retrograde way and the canal was irrigated with 1% sodium hypochlorite. The teeth were assigned to two groups:in group I, root surface was treated with 1% sodium hypochlorite for 10 min (changing the solution every 5 min), rinsed with saline for 10 min and immersed in 2% acidulated-phosphate sodium fluoride for 10 min; in group II, root surfaces were treated in the same way as described above, except for the application of Emdogain((R)) instead of sodium fluoride. The teeth were filled with calcium hydroxide (in group II right before Emdogain((R)) was applied) and replanted. All animals received antibiotic therapy. The rats were killed by anesthetic overdose 10 and 60 days after replantation. The pieces containing the replanted teeth were removed, fixated, decalcified and paraffin-embedded. Semi-serial 6-mu m-thick sections were obtained and stained with hematoxylin and eosin for histologic and histometric analyses. The use of 2% acidulated-phosphate sodium fluoride provided more areas of replacement resorption. The use of Emdogain((R)) resulted in more areas of ankylosis and was therefore not able to avoid dentoalveolar ankylosis. It may be concluded that neither 2% acidulated-phosphate sodium fluoride nor Emdogain((R)) were able to prevent root resorption in delayed tooth replantation in rats.

Use of vitamin C in delayed tooth replantation

O objetivo deste trabalho foi avaliar microscopicamente, em reimplantes tardios de dentes de rato, os efeitos do tratamento da superfície radicular com diferentes soluções. Foram utilizados 30 ratos Rattus norvegicus albinos da linhagem Wistar que tiveram seus incisivos centrais extraídos e deixados sobre a bancada por 6 h. As polpas foram extirpadas e os canais irrigados com solução de hipoclorito de sódio a 1%. Após o preparo endodôntico, a superfície radicular de cada dente foi tratada com solução de hipoclorito de sódio a 1% por 10 min (trocada a cada 5 min) seguida de soro fisiológico por 10 min, e os dentes foram divididos em três grupos com 10 espécimes em cada um. Nos Grupos I, II e III, respectivamente, a superfície radicular foi tratada com fluoreto de sódio fosfato acidulado a 2%, vitamina C e vitamina C efervescente (2 g, Redoxon®). Após obturação com pasta de hidróxido de cálcio os dentes foram reimplantados e os animais foram sacrificados aos 10 e 60 dias. O Grupo I apresentou maiores áreas de reabsorção por substituição e anquilose. Comparando as formas de vitamina C utilizadas, a efervescente (Grupo III) foi a que apresentou resultados mais favoráveis com mais áreas de anquilose e reabsorção por substituição que áreas de reabsorção inflamatória.

Calcium Hydroxide Mixed With Camphoric p-Monochlorophenol or Chlorhexidine in Delayed Tooth Replantation

This study evaluated the repair process after delayed replantation of rat teeth, using calcium hydroxide (Ca(OH)(2)) mixed with camphorated p-monochlorophenol (CMCP), chlorhexidine 2% (CHX), or saline as temporary root canal dressing to prevent and/or control inflammatory radicular resorption. Thirty Wistar rats (Rattus norvegicus albinos) had their right upper incisor extracted, which was bench-dried for 60 minutes. The dental papilla, the enamel organ, the dental pulp, and the periodontal ligament were removed. The teeth were immersed in 2% acidulated-phosphate sodium fluoride solution for 10 minutes. The root canals were dried with absorbent paper cones and divided into 3 groups of 10 animals according to root canal dressing used: group 1: Ca(OH)(2) + saline, group 2: Ca(OH)(2) + CMCP, and group 3: Ca(OH)(2) + CHX 2%. Before replanting, the teeth sockets were irrigated with saline. Histological analysis revealed the presence of inflammatory resorption, replacement resorption, and ankylosis in all 3 groups. Statistical analysis showed a significant difference between group 3 and the other groups. The use of Ca(OH)(2) mixed with CMCP or CHX did not show an advantage over the use of Ca(OH)(2) mixed with saline in preventing and/or controlling inflammatory resorption in delayed replantation of rat teeth.

Periapical tissue reactions to calcium hydroxide and MTA after external root resorption as a sequela of delayed tooth replantation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Treatment of root surface in delayed tooth replantation: a review of literature

The time elapsed between a trauma and tooth replantation usually ranges from 1 to 4 h. The chances of root surface damage are higher when tooth replantation is not performed immediately or if the avulsed tooth is not stored in an adequate medium. This invariably leads to necrosis of pulp tissue, periodontal ligament cells and cementum, thus increasing the possibility of root resorption, which is the main cause of loss of replanted teeth. This paper presents a comprehensive review of literature on root surface treatments performed in cases of delayed tooth replantation with necrotic cemental periodontal ligament. Journal articles retrieved from PubMed/MedLine, Bireme and Scielo databases were reviewed. It was observed that, when there are no periodontal ligament remnants and contamination is under control, replacement resorption and ankylosis are the best results and that, although these events will end up leading to tooth loss, this will happen slowly with no loss of the alveolar ridge height, which is important for future prosthesis planning.

Analysis of the healing process in delayed tooth replantation after root canal filling with calcium hydroxide, Sealapex and Endofill: a microscopic study in rats

The major concern in the therapeutics of tooth replantation refers to the occurrence of root resorption and different approaches have been proposed to prevent or treat these complications. The purpose of this study was to evaluate tissue response to delayed replantation of anterior rat teeth treated endodontically using calcium hydroxide, Sealapex, and Endofill without the placement of gutta-percha cones. Thirty rats had their right upper incisor extracted and maintained in dry storage for 60 min. After removal of the dental papilla, enamel organ, pulp tissue, and periodontal ligament remnants, the teeth were immersed in 2% sodium fluoride phosphate acidulated, pH 5.5, for 10 min. The root canals were dried with absorbent paper points and the teeth were assigned to three groups (n = 10) according to the filling material. Group I - calcium hydroxide and propyleneglycol paste, Group II - Sealapex, and Group III - Endofill. The sockets were irrigated with saline and the teeth were replanted. Replacement resorption, inflammatory resorption and ankylosis were observed in all groups. Although the occurrence of inflammatory resorption was less frequent in Group I, there were no statistically significant differences among the groups. It may be concluded that compared to the paste, filling the root canals with Sealapex and Endofill sealers without the placement of gutta-percha cones did not provide better results.

Effect of root surface treatment with propolis and fluoride in delayed tooth replantation in rats

Replantation is an acceptable option for treatment of an avulsed permanent tooth. Nevertheless, an extended extraoral period damages the periodontal ligament and results in external root resorption. The purpose of this study was to assess by histologic and histometric analysis, the influence of propolis 15% (natural resinous substance collected by Apis mellifera bees from various plants) and the fluoride solution used as root surface treatment on the healing process after delayed tooth replantation. Thirty Wistar (Rattus norvegicus albinus) rats were submitted to extraction of their upper right incisor. The teeth were maintained in a dry environment for 60 min. After this, the pulp was extirpated and the papilla, enamel organ and periodontal ligament were removed with scalpel. The teeth were divided into three experimental groups: Group I - teeth immersed in 20 ml of physiologic saline; Group II - teeth immersed in 20 ml of 2% acidulated phosphate sodium fluoride; Group III - teeth immersed in 20 ml of 15% propolis. After 10 min of immersion in the solutions, the root canals were dried and filled with calcium hydroxide paste and the teeth were replanted. The animals were euthanized 60 days after replantation. The results showed that similar external root resorption was seen in the propolis and fluoride groups. Teeth treated with physiologic saline tended to have more inflammatory root resorption compared with those treated with fluoride or propolis. However, the comparative analysis did not reveal statistically significant differences (P > 0.05) between the treatment modalities when used for delayed tooth replantation.

Delayed replantation of rat teeth after use of reconstituted powdered milk as a storage medium

Minimal extraoral dry storage period and moist storage for the avulsed tooth are identified as key steps for the treatment protocol of tooth replantation. Among the possible moist storage media, bovine milk has stood out because of its capacity of preserving the integrity of the periodontal ligament (PDL) fibers. This condition has attracted the attention to investigate the use of powdered milk, which is one of the presentation forms of bovine milk, as a feasible storage medium in cases of delayed tooth replantation. The aim of this study was to evaluate the healing process after delayed replantation of rat teeth stored in reconstituted powdered milk and long shelf-life (ultra high temperature) whole milk. Forty maxillary right rat incisors were assigned to four groups (n = 10): group I - the teeth were extracted and immediately replanted into theirs sockets; group II - the teeth were stored for 60 min in 200 ml of freshly reconstituted powdered milk; group III - the teeth were stored for 60 min in 200 ml of long shelf-life whole milk; group IV - the teeth were kept dry for the same time. All procedures were performed at room temperature. Next, the root canals of teeth in groups II, III, and IV were instrumented, filled with a calcium hydroxide-based paste, and replanted into their sockets. All animals received systemic antibiotic therapy and were killed by anesthetic overdose 60 days after replantation. The pieces containing the replanted teeth were removed, fixed, decalcified, and paraffin-embedded. Semi-serial 6-mu m-thick sections were obtained and stained with hematoxylin and eosin for histomorphological analysis. There was statistically significant difference (P < 0.05) between groups I and IV regarding the presence of replacement resorption and PDL remnants on root surface. The powdered milk and long shelf-life whole milk presented similar results to each other and may be indicated as storage media for avulsed teeth.

Success rate of immediate nonfunctional loaded single-tooth implants: Immediate versus delayed implantation

Purpose: The aim of this study was to evaluate the success rate of maxillary immediate nonfunctional single-tooth loaded implants used into fresh extraction sites (immediate placement condition) or healed ridge (delayed placement condition).Materials and Methods: Eighty-two dental implants were placed in the maxilla of 64 consecutive patients from Private practice office and from a specialization course in Implantology. Forty-six implants were inserted under immediate placement condition, and 36 were inserted under delayed placement condition. The criteria used to evaluate success rate were those previously described by Albrektsson and Zarb (Int J Prosthodont 1993;6: 95-105), and follow-up period ranged from 18.0 to 39.7 months.Results: Seventy-nine implants fulfilled the success rate criteria (96.3%). Moreover, differences concerning implantation condition were not significant (P = 0.33, Qui-square test): three of the failed implants were from immediate placement group (success rate of 93.5%), and none was from delayed placement group (success rate of 100.0%).Conclusion: In the present sample, no statistically significant differences were detected for immediate nonfunctional single-tooth loaded implants under immediate placement condition in comparison with those inserted under delayed placement condition; both protocols had high success rate in maxillary incisors, canines, and premolars areas.

Use of computerized tomography for diagnosis and follow-up after endodontic surgery: clinical case report with 8 years of follow-up

Computerized tomography (CT) is a valuable tool for diagnosis and planning in conventional and surgical endodontic therapy. This case report describes the use of CT in the diagnosis of a periapical lesion undetected by periapical radiography in the mandibular molar area. The CT also showed a possible mesial root perforation associated with the lesion. Following CT, surgical planning, periradicular curettage, and sealing of the root perforation were performed. Eight years after surgery, cone beam CT revealed periapical bone repair. Computerized tomography can be an important resource for diagnosis and planning in conventional and surgical endodontic therapy, as well as for evaluation of post-treatment bone repair. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2010; 109: 629-633)

Coagglutination for viral DNA preparation of canine parvovirus for molecular diagnosis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Prostate carcinogenesis induced by N-methyl-N-nitrosourea (mnu) in gerbils: Histopathological diagnosis and potential invasiveness mediated by extracellular matrix components

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Diagnosis of Giardia infections by PCR-based methods in children of an endemic area

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)