Anatomical and histological characteristics of teeth in agouti (Dasyprocta prymnolopha Wagler, 1831)

A cutia espécie Dasyprocta prymnolopha (D. prymnolopha) é um roedor de tamanho médio, diurno e característico do Nordeste do Brasil, sul da Amazônia. Vários estudos têm sido feitos sobre estes roedores. No entanto, há uma carência de estudos do sistema estomatognático, em particular, a morfologia dos dentes. Assim, esta pesquisa procura descrever aspectos anatômicos e histológicos dos dentes cutia. Para isto, nós utilizamos cutias adultas, em que as mensurações e as descrições dos dentes e dos tecidos dentais foram feitas. Observou-se que a arcada dentária de D. prymnolopha é composta por vinte dentes, distribuídas uniformemente no arco superior e inferior, sendo os dentes inferiores, maiores do que os seus correspondentes superiores. Os incisivos são maiores, e entre os pré-molares e molares posteriores, existe um aumento gradual no comprimento do arco anterior-posterior. No exame microscópico, uma forma prismática foi observada o que consiste de prismas de esmalte dispostos em diferentes direções, atrás do esmalte e dentina com túbulos dentinários com padrão tubular de diâmetro variável e distantes entre si, mostrando também um caminho sinuoso a partir da parte interna da junção com o esmalte mais superficial. A análise morfológica dos tecidos dentários mostrou um esmalte com a organização estrutural adaptada para o ato de mastigar e dentina de alto impacto compatível com a função do padrão tubular de resiliência e amortecimento mecânico de forças mastigatórias, como encontrado em animais maiores, confirmando o entendimento de hábitos alimentares que definem muito das suas funções ecológicas dentro do ecossistema em que vivem.

Mechanical isolation of capuchin monkey (Cebus apella) preantral ovarian follicles

O presente trabalho objetivou adaptar um procedimento mecânico para o isolamento de folículos pré-antrais a partir de ovários de Cebus apella. Para isso, foi testado o efeito do intervalo de cortes seriados do tissue chopper sobre o número de folículos pré-antrais isolados a partir de ovários (n=6) de três fêmeas de C. apella, duas pré-púberes e uma adulta. Os ovários foram divididos em quatro partes iguais e fragmentados com auxílio de um tissue chopper, ajustado para a realização de secções seriadas a intervalos de 250, 500, 750 e 1000µm, respectivamente. Os folículos isolados foram contados em câmara de Neubauer e classificados em primordiais, primários e secundários. O número (média ± EP) de folículos pré-antrais isolados de 1/4 de ovário variou de 68.330+17.590, no intervalo de corte de 1.000µm, a 300.830+111.460, no intervalo de corte de 500µm, o de melhores resultados. O diâmetro médio dos folículos pré-antrais isolados variou de 11,6µm a 27, 8µm.

Histological study of capuchin monkey (Cebus apella) ovarian follicles

O objetivo do presente trabalho foi obter dados quantitativos e qualitativos da população folicular ovariana de fêmeas de Cebus apella. Foram obtidos 7 ovários de 4 fêmeas adultas de C. apella através de ovariectomia. Os ovários foram submetidos à preparação para histologia ótica de rotina. O número de folículos pré-antrais e antrais por ovário foi estimado utilizando o Método Fracionador. Os folículos pré-antrais foram classificados em primordial, transição, primário e secundário. Foram considerados folículos antrais todos aqueles que apresentavam uma cavidade antral. Todos os folículos contados foram classificados em normais ou degenerados. Com o intuito de acompanhar o desenvolvimento folicular, os diâmetros médios folicular, oocitário e do núcleo do oócito foram determinados. Todos os resultados foram apresentados em Média ± Erro Padrão. A população média de folículos pré-antrais foi de 56.938 ± 21.888 e 49.133 ± 26.896 para os ovários direito e esquerdo, respectivamente. A percentagem de folículos pré-antrais estimados normais foi de 80,00 ± 4,95 %. O diâmetro médio folicular variou de 22,0 ± 0,5 µm a 61,2 ± 4,0 µm. No tocante aos folículos antrais, a população média de folículos normais e degenerados por ovário foi de 60,0 ± 19,0 e 3 ± 1,8 folículos, respectivamente. O diâmetro médio folicular foi de 514,4 ± 56,6 µm. Para concluir, as informações obtidas neste trabalho poderão servir como parâmetro para posteriores estudos in vivo ou in vitro da foliculogênese de primatas não-humanos neotropicais da espécie C. apella.

In Vivo study of an intracanal dressing of calcium hydroxide/chlorhexidine in necrotic primary teeth

AIM:To evaluate the clinical and radiographic success of endodontic treatment in human primary teeth with necrotic pulp with and without radiographically visible furcal/periapical lesion treated with a calcium hydroxide (CH) and chlorhexidine (CHX) intracanal dressing. The tested hypothesis was that there is no difference in the clinical and radiographic success in primary teeth medicated with CH pastes prepared with polyethylene glycol (PEG) or CHX.METHODS:Thirty-two teeth with necrotic pulp were used in this randomized clinical study: 12 without and 20 with lesion. Canals were prepared and medicated with CH pastes with polyethylene glycol (CH/PEG) (n=16) or 2% CHX gel (CH/CHX) (n=16). Definitive filling was done after 30 days. The teeth were clinically and radiographically examined during 12 months to determine the success of the endodontic therapy. Data from clinical and radiographic examination of the initial condition and 12 months after treatment were compared using the Z test (α = 0.05).RESULTS:There was no significant difference (p>0.05) in the success rate of teeth with and without lesion medicated with CH/PEG or CH/CHX. No significant difference (p>0.05) was found between the pastes regardless of the presence of lesion.CONCLUSIONS:Combination of CHX and CH was not more effective than the CH/PEG paste, as similar clinical and radiographic success rate was observed in teeth medicated with either type of intracanal dressing.

Effect of Indomethacin on Surface Treatment and Intracanal Dressing of Replanted Teeth in Dogs

Purpose: This study evaluated the healing process of teeth replanted after root treatment and intracanal dressing with indomethacin alone or indomethacin with calcium hydroxide (Ca[OH](2)).Materials and Methods: Through a case-control study, 24 teeth of 6 adult dogs were extracted, dried, and divided into 4 groups according to the root surface treatment protocols performed before replantation and the intracanal medication used after replantation. In group 1 (negative control), root surfaces were treated by immersion in a 0.9% saline solution and then replanted. In the other groups, the roots were immersed for 10 minutes in Ca(OH)(2) (group 2), indomethacin (group 3), or a solution of indomethacin and Ca(OH)(2) (group 4). After 2 weeks, group 1 teeth were subjected to single-visit root canal treatment and obturation with gutta-percha and sealer consisting of zinc oxide and eugenol. The teeth in the other groups were subjected to intracanal dressing with the same material used for immersion. After an additional period of 28 weeks, the animals were euthanized and the jaws containing the replanted teeth were processed for histologic analysis. Histometric values were statistically analyzed, with significance set at a P value less than or equal to .05.Results: Group 1 exhibited significantly more normal periodontium than group 4 (P = .02). Total resorption was greater in group 4 than in group 1 (P = .02). No statistically significant difference in the percentage of surface resorption or in total inactive resorption was observed between the groups.Conclusions: The findings of this study suggest that intracanal dressing and topical root treatment with Ca(OH)(2) with or without indomethacin is not recommended for teeth dried for 50 minutes, but the use of indomethacin alone as root surface treatment for delayed tooth replantation deserves further study using longer drying periods. In addition, the present results suggest that a single-visit root canal, performed up to 2 weeks after replantation, might be indicated for teeth dried for up to 50 minutes. (C) 2014 American Association of Oral and Maxillofacial Surgeons

Intrinsic organization of the suprachiasmatic nucleus in the capuchin monkey

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

Filling of extraction sockets of feline maxillary canine teeth with autogenous bone or bioactive glass

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

Color degradation of acrylic resin denture teeth as a function of liquid diet: ultraviolet-visible reflection analysis

The effect of different beverages on acrylic resin denture teeth color degradation is evaluated. Ten acrylic resin denture teeth brands were evaluated: Art Plus (AP), Biolux (BX), Biotone IPN (BI), Magister (MG), Mondial 6 (MD), Premium 6 (PR), SR Vivodent PE (SR), Trilux (TR), Trubyte Biotone (TB), and Vipi Dent Plus (VP). Teeth were immersed in staining solutions (coffee, cola, and orange juice) or artificial saliva (control) (n = 6) for 1, 7, 15, or 30 days. Specimen colors were evaluated spectrophotometrically based on the Commission Internationale d'Eclairage L*a*b* system. Color differences (Delta E) were calculated between the baseline and post-staining results. Data were evaluated by analysis of variance and Tukey test (alpha = 0.05). BI (1.82 +/- 0.95) and TR (1.78 +/- 0.72) teeth exhibited the greatest Delta E values, while BX (0.88 +/- 0.43) and MD (1.09 +/- 0.44) teeth were the lowest, regardless of solution and measurement period, and were different from BI and TR teeth (P < 0.05). Cola and coffee promoted higher denture teeth color alterations than orange juice and saliva (P < 0.05). Saliva generated the lowest denture teeth color alterations. Greater immersion times caused higher denture teeth color changes. The lifespan of removable dentures and the aesthetic satisfaction of several edentulous patients may be increased with the use of stain-resistant artificial denture teeth. (C) The Authors.

Histopathological Condition of the Remaining Tissues after Endodontic Infection of Rat Immature Teeth

Introduction: Recently, case reports have shown that immature teeth diagnosed with necrotic pulp and periapical periodontitis can be repaired through a regenerative endodontic procedure. True regeneration depends on the presence of stem cells in the remaining vital tissues. The aim of this study was to evaluate the histologic condition of the pulp tissue, root apical papilla, and periapical tissues after inducing endodontic infection in immature rat teeth for different periods. Methods: This study evaluated 18 first upper rat molars (36 roots). Periapical lesions were induced and were confirmed radiographically, and the animals were divided into 3 groups according to the days of pulp exposure for endodontic infection induction: 30, 60, and 90 days. Histologic analysis was performed in 5 different areas (ie, cervical, middle, and apical root canal thirds; the apical papilla; and the periapex surrounding the apical papilla). Results: At 30 days, one third of the specimens still showed vital but intensely inflamed pulp tissue in the apical third and vital apical papilla with varying degrees of inflammation. After 60 days, the results were similar with respect to the apical pulp tissue and apical papilla. Completely necrotic pulp tissue in the space canal and vital apical papilla were observed in about 67% of the cases after 90 days. Conclusions: Vital pulp tissue was observed in the apical third until 60 days and in the vital apical papilla until 90 days of infection in a rat model.

Two-year Clinical Performance of Self-etching Adhesive Systems in Composite Restorations of Anterior Teeth

Objective: The aim of this study was to evaluate the two-year clinical performance of Class III, IV, and V composite restorations using a two-step etch-and-rinse adhesive system (2-ERA) and three one-step self-etching adhesive systems (1-SEAs).Material and Methods: Two hundred Class III, IV, and V composite restorations were placed into 50 patients. Each patient received four composite restorations (Amaris, Voco), and these restorations were bonded with one of three 1-SEAs (Futurabond M, Voco; Clearfil S3 Bond, Kuraray; and Optibond All-in-One, Kerr) or one 2-ERA (Adper Single Bond 2/3M ESPE). The four adhesive systems were evaluated at baseline and after 24 months using the following criteria: restoration retention, marginal integrity, marginal discoloration, caries occurrence, postoperative sensitivity and preservation of tooth vitality. After two years, 162 restorations were evaluated in 41 patients. Data were analyzed using the chi(2) test (p<0.05).Results: There were no statistically significant differences between the 2-ERA and the 1-SEAs regarding the evaluated parameters (p>0.05).Conclusion: The 1-SEAs showed good clinical performance at the end of 24 months.

Bonding durability of dental sealants to deciduous and permanent teeth

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

Mini-implants as provisional anchorage for the replacement of missing anterior teeth: A clinical report

This clinical report describes an adult patient referred for orthodontic treatment with mini-implants as anchorage to correct the root angulation of maxillary lateral incisors. The purpose of this report was to demonstrate the versatility of mini-implants placed in a vertical direction in esthetic areas. During orthodontic treatment, some aspects must be observed to preserve the interim restoration against the occlusal loads to avoid screw fracture. A fixed appliance was placed to correct the position of the maxillary anterior teeth and to complete the treatment. Acceptable esthetics and function were achieved.

Phototherapy up-regulates dentin matrix proteins expression and synthesis by stem cells from human-exfoliated deciduous teeth

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

Influence Analysis of Cleft Type and Supernumerary Teeth Eruption in the Prognosis of Bone Graft in Patients With Cleft Palate

Objective: The aim of this study was to investigate the influence of cleft type and supernumerary tooth eruption on the treatment of palatal clefts with alveolar bone grafts.Materials and Methods: In this article, medical records of 40 patients with palatal clefts and associated supernumerary teeth who were treated with alveolar bone grafting in the Hospital for Craniofacial Anomalies Rehabilitation were assessed. The patients were studied to assess the influence of supernumerary teeth and the cleft severity on the prognosis of the alveolar bone graft.Results: Forty medical records were included in the assessment. When the teeth in the cleft had an anatomic shape close to canine, we called them precanine. When they were very small or malformed, we called them anomalous lateral incisors. The teeth studied showed good prognoses and were more expressive in the preforaminal clefts (87.5%) than in the transforaminal ones (62.5%). Moreover, the transforaminal clefts presented a higher percentage in satisfactory and poor prognoses (37.5%). The authors found that supernumerary teeth influenced the maintenance of alveolar bone graft height and that transforaminal clefts presented a worse prognosis than preforaminal clefts.