Transdentinal protective role of sodium ascorbate against the cytopathic effects of H2O2 released from bleaching agents

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

Clinical and microbiological performance of resin-modified glass-ionomer liners after incomplete dentine caries removal

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

Effects of intrapulpal temperature change induced by visible light units on the metabolism of odontoblast-like cells

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

Cytotoxicity of resin-based light-cured liners

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Alternative Treatment Modalities for Immature Intruded Permanent Incisors: Report of 2 Cases

Intrusion of permanent teeth is one of the most severe types of traumatic injuries. Different treatment strategies have been proposed, and the best approach for each case depends on the stage of root development, severity of the intrusive luxation, presence of alveolar fracture and number of intruded teeth. The purpose of this paper is to describe the treatment management of 2 cases of severely intruded immature permanent maxillary central incisors in 71/2- and 8-year-old children. In case 1, the traumatized tooth was treated by surgical repositioning, while in case 2 watchful waiting for spontaneous re-eruption was the treatment of choice. Treatment strategies were successful in both cases, as demonstrated by the continuation of root development, maintenance of pulp vitality, and absence of signs of per/apical pathosis during the follow-up period. Regardless of the treatment strategy, traumatically intruded teeth should undergo periodical clinical and radiographic surveillance on a long-term basis to allow early detection of possible complications. (Pediotr Dent 2009;31:340-5) Received March 11, 2008 vertical bar Last Revision June 25, 2008 vertical bar Revision Accepted July 16, 2008

Transdentinal diffusion and cytotoxicity of self-etching adhesive systems

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Longitudinal clinical and radiographic evaluation of severely intruded permanent incisors in a pediatric population

Intrusion is defined as the axial dislodgment of the tooth into its socket and is considered one of the most severe types of dental trauma. This longitudinal outcome study was undertaken to evaluate clinically and radiographically severely intruded permanent incisors in a population of children and adolescents. All cases were treated between September 2003 and February 2008 in a dental trauma service. Clinical and radiographic data were collected from 12 patients (eight males and four females) that represented 15 permanent maxillary incisors. Mean age at the time of injury was 8 years and 9 months (range 7-14 years and 8 months). Mean time elapsed to follow-up was 26.6 months (range 10-51 months). The analysis of data showed that tooth intrusion was twice as frequent in males. The maxillary central incisors were the most commonly intruded teeth (93.3%), and falling at home was the main etiologic factor (60%). More than half of the cases (53.3%) were multiple intrusions, 73.3% of the intruded teeth had incomplete root formation and 66.6% of the teeth suffered other injuries concomitant to intrusion. Immediate surgical repositioning was the treatment of choice in 66.7% of the cases, while watchful waiting for the tooth to return to its pre-injury position was adopted in 33.3% of the cases. The teeth that suffered additional injuries to the intrusive luxation presented a fivefold increased relative risk of developing pulp necrosis. The immature teeth had six times more chances of presenting pulp canal obliteration that the mature teeth and a lower risk of developing root resorption. The most frequent post-injury complications were pulp necrosis (73.3%), marginal bone loss (60%), inflammatory root resorption (40%), pulp canal obliteration (26.7%) and replacement root resorption (20%). From the results of this study, it was not possible to determine whether the type immediate treatment had any influence on the appearance of sequelae like pulp necrosis and root resorption after intrusive luxation, but the existence of additional injuries and the stage of root development influenced the clinical case outcome in a negative and positive manner, respectively.

Cytotoxic effect of a 35% hydrogen peroxide bleaching gel on odontoblast-like MDPC-23 cells

Objective. This study evaluated transenamel and transdentinal cytotoxic effects of a bleaching gel on the MDPC-23 cell line.Study design. Discs obtained from bovine incisors were placed in a metallic device to simulate an in vivo pulp chamber. Groups were formed according to the enamel surface treatment: G1: 35% H(2)O(2) bleaching gel; G2: 35% H2O2 bleaching gel + halogen light; G3: halogen light; and G4: control. Cell metabolism was evaluated by the methyltetrazolium assay and cell morphology by scanning electron microscopy.Results. Cell metabolism decreased by 31.7%, 41.6%, and 11.5% in G1, G2, and G3, respectively. Cytotoxic effects observed in G2 were significantly more severe compared with G3 and G4. In G1 and G2, a smaller number of viable cells with major morphologic alterations remained adhered to dentin.Conclusion. The bleaching gel associated with light presented transenamel and transdentinal cytotoxic effects characterised by direct damage to odontoblasts and decrease of their metabolic activity. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2009; 108: 458-464)

Response of human pulps after professionally applied vital tooth bleaching

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Transdentinal cytotoxic effects of different concentrations of chlorhexidine gel applied on acid-conditioned dentin substrate

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Trans-enamel and trans-dentinal cytotoxic effects of a 35% H2O2 bleaching gel on cultured odontoblast cell lines after consecutive applications

To evaluate the trans-enamel and trans-dentinal cytotoxic effects of a 35% H2O2 bleaching gel on an odontoblast-like cell lines (MDPC-23) after consecutive applications.Fifteen enamel/dentine discs were obtained from bovine central incisor teeth and placed individually in artificial pulp chambers. Three groups (n = 5 discs) were formed according to the following enamel treatments: G1: 35% H2O2 bleaching gel (15 min); G2: 35% H2O2 bleaching gel (15 min) + halogen light (20 s); G3: control (no treatment). After repeating the treatments three consecutive times, the extracts (culture medium + gel components that had diffused through enamel/dentine discs) in contact with the dentine were collected and applied to previously cultured MDPC-23 cells (50 000 cells cm(-2)) for 24 h. Cell metabolism was evaluated by the MTT assay and data were analysed statistically (alpha = 5%; Kruskal-Wallis and Mann-Whitney U-test). Cell morphology was analysed by scanning electron microscopy.Cell metabolism decreased by 92.03% and 82.47% in G1 and G2 respectively. G1 and G2 differed significantly (P < 0.05) from G3. Regardless of halogen light activation, the application of the bleaching gel on the cultured odontoblast-like cells caused significantly more severe cytotoxic effects than those observed in the nontreated control group. In addition, significant morphological cell alterations were observed in G1 and G2.After three consecutive applications of a 35% H2O2 bleaching agent, the diffusion of the gel components through enamel and dentine caused severe toxic effects to cultured pulp cells.

Increased Viability of Odontoblast-Like Cells Subjected to Low-Level Laser Irradiation

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

Conservative management of a dentigerous cyst secondary to primary tooth trauma

Pulp necrosis is a commonly observed sequela in traumatized primary teeth and is one of the possible etiologic factors for the development of dentigerous teeth. This article reports the case of a dentigerous cyst associated with the germ of a permanent maxillary central incisor that developed secondary to trauma to the predecessor primary incisor. The therapeutic approach included endodontic treatment of the primary tooth and marsupialization of the lesion. After 36 months of follow up, the permanent incisor presented with normal physiologic conditions, absence of dental anomalies and erupted in its correct position in the oral cavity. In conclusion, with proper case selection, marsupialization might be a good treatment option for conservative management of dentigerous cysts.

Evaluation of 2 endodontic techniques used to treat human primary molars with furcation radiolucency area: A 48-month radiographic study

Objective: To evaluate 2 techniques for the treatment of human primary molars with necrotic Pulp and bifurcation bone loss by means of radiographic examination for 48 months. Method and Materials: Fifty-one mandibular primary molars were evaluated in children ranging from 4.5 to 6.5 years of age. The teeth with necrotic pulp and bifurcation bone loss were diagnosed by radiographic examination. The teeth were divided into 2 groups: group 1 (28 teeth)-pulpotomy technique using formocresol as a temporary dressing between sessions and coronal chamber obturation with zinc oxide-eugenol cement; and group 2 (23 teeth)-pulpectomy technique with calcium hydroxide paste as a temporary dressing between sessions and root canal obturation with a dense Calcium hydroxide paste. Standardized radiographs were taken immediately after the fillings were completed and after 12, 24, 36, and 48 months. The radiographs were digitized and analyzed with software that outlined and measured the bifurcation radiolucency. Results: Bifurcation radiolucency reduced significantly or repaired completely for both treatnients in the first 12 months. Minor radiographic reduction of the lesion was observed from 12 to 24 months, and no significant reduction of the remaining radioulcent area was observed from 24 to 48 months after treatment. Conclusion: The 2 endodontic techniques evaluated showed similar results. The main effect of treatment on the lesion repair was obtained in the first year after treatment.

Dens invaginatus type III: report of a case and 10-year radiographic follow-up

Aim the purpose of this article is to report the 10-year follow-up of a right mandibular central incisor with 'dens invaginatus' that was root filled.Summary 'Dens invaginatus ' is a rare malformation of teeth, probably resulting from an infolding of the dental papilla during tooth development. It has alternatively been called 'dens in dente' and 'dilated composite odontome'. Radiographic examination may clearly demonstrate this feature, although no signs may be recognized clinically. If no entrance to the invagination can be detected and there are no signs of pulp pathosis, then no treatment is required other than fissure sealing of the invagination. In deep invaginations, it is likely that root-canal treatment may be required. Occasionally, when the tooth has an immature root, apexification is necessary. Root-canal treatment of a right mandibular central incisor with 'dens invaginatus ' is described along with 10-year follow-up.Key learning pointsBoth clinical and radiographic examinations are necessary to determine morphological features of teeth before root-canal treatment.Sensibility testing to determine the pulp condition is critical prior to treatment.