A hydrogel scaffold that maintains viability and supports differentiation of dental pulp stem cells

Objectives: The clinical translation of stem cell-based Regenerative Endodontics demands further development of suitable injectable scaffolds. Puramatrix™ is a defined, self-assembling peptide hydrogel which instantaneously polymerizes under normal physiological conditions. Here, we assessed the compatibility of Puramatrix™ with dental pulp stem cell (DPSC) growth and differentiation. Methods: DPSC cells were grown in 0.05-0.25% Puramatrix™. Cell viability was measured colorimetrically using the WST-1 assay. Cell morphology was observed in 3D modeling using confocal microscopy. In addition, we used the human tooth slice model with Puramatrix™ to verify DPSC differentiation into odontoblast-like cells, as measured by expression of DSPP and DMP-1. Results: DPSC survived and proliferated in Puramatrix™ for at least three weeks in culture. Confocal microscopy revealed that cells seeded in Puramatrix™ presented morphological features of healthy cells, and some cells exhibited cytoplasmic elongations. Notably, after 21 days in tooth slices containing Puramatrix™, DPSC cells expressed DMP-1 and DSPP, putative markers of odontoblastic differentiation. Significance: Collectively, these data suggest that self-assembling peptide hydrogels might be useful injectable scaffolds for stem cell-based Regenerative Endodontics. © 2012 Academy of Dental Materials.

Titanium in Dentistry: Historical development, state of the art and future perspectives

Titanium is a metallic element known by several attractive characteristics, such as biocompatibility, excellent corrosion resistance and high mechanical resistance. It is widely used in Dentistry, with high success rates, providing a favorable biological response when in contact with live tissues. Therefore, the objective of this study was to describe the different uses of titanium in Dentistry, reviewing its historical development and discoursing about its state of art and future perspective of its utilization. A search in the MEDLINE/PubMed database was performed using the terms 'titanium', 'dentistry' and 'implants'. The title and abstract of articles were read, and after this first screening 20 articles were selected and their full-texts were downloaded. Additional text books and manual search of reference lists within selected articles were included. Correlated literature showed that titanium is the most used metal in Implantology for manufacturing osseointegrated implants and their systems, with a totally consolidated utilization. Moreover, titanium can be also employed in prosthodontics to obtain frameworks. However, problems related to its machining, casting, welding and ceramic application for dental prosthesis are still limiting its use. In Endodontics, titanium has been used in association to nickel for manufacturing rotatory instruments, providing a higher resistance to deformation. However, although the different possibilities of using titanium in modern Dentistry, its use for prostheses frameworks still needs technological improvements in order to surpass its limitations. © 2012 Indian Prosthodontic Society.

Evaluation of a photographic method to measure dental angulation

Objetivo: analisar a confiabilidade e reprodutibilidade de um método simplificado para análise da angulação dentária que faz uso de fotografias digitalizadas de modelos de gesso. Métodos: foram realizadas fotografias digitalizadas e padronizadas de modelos de gesso, posteriormente transportadas para um programa gráfico de leitura de ângulos, para a obtenção das medidas. Tais procedimentos foram repetidos para avaliação do erro do método casual e para a análise da reprodutibilidade por meio da Correlação Intraclasse. A amostra constituiu-se de 12 indivíduos com dentição permanente completa e não tratados ortodonticamente, sendo seis do sexo masculino e seis do feminino. As análises foram feitas bilateralmente, gerando 24 medidas. Resultados: o erro casual mostrou uma variação de 0,77 a 2,55º para a angulação dos dentes. A análise estatística revelou que o método apresenta uma excelente reprodutibilidade (r = 0,65 - 0,91; p < 0,0001) para todos os dentes, exceto para os pré-molares superiores, mas ainda assim estatisticamente significativa (p < 0,001). Conclusão: o método proposto apresenta confiabilidade suficiente para justificar seu uso no desenvolvimento de pesquisas científicas, bem como na prática clínica.

Mandibular growth and dentoalveolar development in the treatment of Class II, division 1, malocclusion using Balters Bionator according to the skeletal maturation

OBJECTIVE: The purpose of the study was to evaluate the influence of the skeletal maturation in the mandibular and dentoalveolar growth and development during the Class II, division 1, malocclusion correction with Balters bionator. METHODS: Three groups of children with Class II, division 1, malocclusion were evaluated. Two of them were treated for one year with the bionator of Balters appliance in different skeletal ages (Group 1: 6 children, 7 to 8 years old and Group 2: 10 children, 9 to 10 years old) and the other one was followed without treatment (Control Group: 7 children, 8 to 9 years old). Lateral 45 degree cephalometric radiographs were used for the evaluation of the mandibular growth and dentoalveolar development. Tantalum metallic implants were used as fixed and stable references for radiograph superimposition and data acquisition. Student's t test was used in the statistical analysis of the displacement of the points in the condyle, ramus, mandibular base and dental points. Analysis of variance one-fixed criteria was used to evaluate group differences (95% of level of significance). RESULTS: The intragroup evaluation showed that all groups present significant skeletal growth for all points analyzed (1.2 to 3.7 mm), but in an intergroup comparison, the increment of the mandibular growth in the condyle, ramus and mandibular base were not statically different. For the dentoalveolar modifications, the less mature children showed greater labial inclination of the lower incisors (1.86 mm) and the most mature children showed greater first permanent molar extrusion (4.8 mm).

A castor oil-containing dental luting agent: effects of cyclic loading and storage time on flexural strength

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

MODIFIED INDEXING TECHNIQUE FOR THE IMMEDIATE INTERIM RESTORATION OF A DENTAL IMPLANT

Because of the functional and esthetic requirements of patients, different techniques have been proposed to reduce the time between dental implant placement and interim restoration fabrication. This article describes a modified indexing technique by using a surgical template for open-tray impression and definitive cast development during immediate loading procedures. This technique does not use a complete impression of the oral cavity and, therefore, is more comfortable, less time consuming, and less expensive. It also allows the fabrication of interim restorations with the optimal shape for developing an adequate emergence profile.

Conhecimento de cárie dental e doença periodontal de professores do ensino fundamental segundo o tipo de instituição (pública ou privada)

Aim: observe the knowledge of dental caries and periodontal disease of primary schoolteachers, according to type of institution (public and private) from Araraquara city. methodology: for that participants were 113 teachers from public schools and 57 from private schools. The instrument of analysis was based on a questionnaire with closed and open questions concerning the etiology, prevention and development of dental caries and periodontal disease. Results: 97,3% of public ́s schoolteachers and 91,2% of private ́s schoolteachers answered that they knows what is dental caries, but they didn ́t answer correctly about the caries etiology as being multifactorial and about methods of prevention. Both of schoolteachers (public and private) had more sucessful when answered about bacterial plaque than periodontal disease and yours manifestation. Conclusion: the dental knowledge of schoolteachers in public and private school was evaluated and limited educational programs should be directed to both public and private schoolteachers, in order to increase the level of dental knowledge of them, so that they can act as educational agents with the children.

Risk muskuloskeletal disorders in upper limbs in dental students: concordance of different methods for estimation of body angle

The purpose of this paper was to evaluate the agreement among different methods used to estimate angular deviation of the body to determine the risk for development of upper limb musculoskeletal disorders in dentistry undergraduates. Materials and Methods: Students (n = 79) enrolled in the final year undergraduate course of the Araraquara School of Dentistry-Sγo Paulo State University-UNESP were evaluated. Photographs were taken of students performing clinical procedures. The work postures adopted by each student were evaluated by means of rapid upper limb assessment (RULA). The basis used to obtain the individual's final risk score is the measurement of the angular deviations in the neutral positions of the regions evaluated. Two methods were used to estimate the angular deviation of the body: Visual exam and Image Tool software. A RULA final risk score was attributed to each procedure the student performed (n = 333). Study of the agreement between the methods about risk of musculoskeletal disorders was conducted by means of Kappa (κ) statistics. The level of significance adopted was 5%. Results: Fair agreement (κ = 0.32) between the evaluated methods was verified. Conclusion: The risk for development of upper limb musculoskeletal disorders by dentistry undergraduates evaluated by using RULA was not in agreement with the results obtained by use of visual exam and Image Tool.

Risk of musculoskeletal disorders in upper limbs in dental students: concordance of different methods for estimation of body angle

The purpose of this paper was to evaluate the agreement among different methods used to estimate angular deviation of the body to determine the risk for development of upper limb musculoskeletal disorders in dentistry undergraduates. Materials and Methods: Students (n = 79) enrolled in the final year undergraduate course of the Araraquara School of Dentistry-Sγo Paulo State University-UNESP were evaluated. Photographs were taken of students performing clinical procedures. The work postures adopted by each student were evaluated by means of rapid upper limb assessment (RULA). The basis used to obtain the individual's final risk score is the measurement of the angular deviations in the neutral positions of the regions evaluated. Two methods were used to estimate the angular deviation of the body: Visual exam and Image Tool software. A RULA final risk score was attributed to each procedure the student performed (n = 333). Study of the agreement between the methods about risk of musculoskeletal disorders was conducted by means of Kappa (κ) statistics. The level of significance adopted was 5%. Results: Fair agreement (κ = 0.32) between the evaluated methods was verified. Conclusion: The risk for development of upper limb musculoskeletal disorders by dentistry undergraduates evaluated by using RULA was not in agreement with the results obtained by use of visual exam and Image Tool.

Perception of Risk of Musculoskeletal Disorders Among Brazilian Dental Students

The aim of this study was to compare the mean scores of perceived risk factors for the development of musculoskeletal disorders in dental students presently pursuing work/study, according to gender, course series, and the presence of pain/discomfort. The participants were 348 students from the undergraduate course in dentistry at a Brazilian public university. The instrument on work-related factors that could contribute to osteomuscular symptoms and part of the Nordic questionnaire were used. The psychometric properties of the first instrument were estimated. A multivariate analysis of variance (MANOVA) revealed that the instrument had a tri-factorial structure (s2 retained: 62.72 percent). The retained factors were repetitiveness, work posture, and external factors. The internal consistency and reproducibility were adequate (α=0.746 to 0.873; p=0.729 to 0.940). Lower mean scores of perceived external factors were observed for the male participants, as well as lower scores in the three dimensions of the instrument for first-year students of the course and for those who did not report pain/discomfort in the neck, feet, and ankles. The authors concluded that the perception of risk factors for musculoskeletal disorders reported in the work/study environment of dental students was significantly related to gender, the course series, and the presence of pain/discomfort.

Dentinogenesis imperfecta type II: approach for dental treatment

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Multidisciplinary approach in the teaching of dental sculpture and anatomy

The purpose of the Dental Sculpture and Anatomy discipline is to introduce undergraduate students to the study of the anatomic and morphological characteristics of permanent and primary human dentition, through classes, books and cognitive and psychomotor activities. This discipline supports the teaching of specific knowledge necessary for a more extensive education, involving interdisciplinarity as a means of knowledge exchange among several areas of dentistry, to achieve comprehensive professional education. Students must recognize the dental morphology from samples of preserved teeth, and reproduce the morphology through three-dimensional models made of stone or wax blocks. In this article, the authors describe the process for producing teeth collars and macro dental models made of stone, their importance and benefits of utilization. The purpose of the study was to encourage the teaching of Dental Sculpture and Anatomy toundergraduate students of the Bauru School of Dentistry, University of Sao Paulo, through activities that would associate theory, practice and the development of manual skills.

Dental mineralization and salivary activity are reduced in offspring of spontaneously hypertensive rats (SHR)

Several pathologies have been diagnosed in children of hypertensive mothers; however, some studies that evaluated the alterations in their oral health are not conclusive. This study analyzed the salivary gland activity and dental mineralization of offsprings of spontaneously hypertensive rats (SHR). Thirty-day-old SHR males and Wistar rats were studied. The salivary flow was evaluated by injection of pilocarpine, the protein concentration and salivary amylase activity, by the Lowry method and kinetic method at 405 nm, respectively. Enamel and dentin mineralization of the mandibular incisors was quantified with aid of the microhardness meter. The results were analyzed by the ANOVA or Student's t test (p<0.05). It was noticed that the salivary flow rate (0.026 mL/min/100 g ± 0.002) and salivary protein concentration (2.26 mg/mL ± 0.14) of SHR offspring were reduced compared to Wistar normotensive offspring (0.036 mL/min/100 g ± 0.003 and 2.91 mg/mL ± 0.27, respectively), yet there was no alteration in amylase activity (SHR: 242.4 U/mL ± 36.9; Wistar: 163.8 U/mL ± 14.1). Microhardness was lower both in enamel (255.8 KHN ± 2.6) and dentin (59.9 KHN ± 0.8) for the SHR teeth compared to the Wistar teeth (enamel: 328.7 KHN ± 3.3 and dentin: 67.1 KHN ± 1.0). These results suggest that the SHR offspring are more susceptible to development of pathologies impairing oral health, once they presented lesser flow and salivary protein concentration and lower dental mineralization.

Risk factors in the mother-child relationship that predispose to the development of early childhood caries

This study focused on the risk factors in mother-child relationship that predispose babies to the development of dental caries. A prospective cohort study with 80 mother-child pairs was conducted. The mothers responded at 12, 18 and 30 months after their children's birth, to questions about variables related to diet, sucking habits, and oral care. Children were clinically examined to verify caries lesions (white spot lesions or cavitation). Data were analysed using Chi squared or Fisher's exact tests. The significance level was set at 5 %. Of the total, 3.75 % showed cavitated lesions after 18 months; 6.25 and 45 % had spot white lesions, respectively, at 18 and 30 months. The cariogenic diet was high at 12 (63.75 %) and 30 (88.75 %) months. Good oral hygiene was present in a minority of children at 12 months (46.25 %), but increased at 30 months (65 %), helping to prevent cavities and white spot lesions over this period (p = 0.0005). The variables of the blocks sucking habits and diet were not associated with caries. The lack of oral care in children was a risk factor for dental caries development.

Diabetes triggers the loss of tooth structure associated to radiographical and histological dental changes and its evolution to progressive pulp and periapical lesions in rats

The aim of this study was to evaluate the putative influence of diabetes without metabolic control in the loss of tooth structure as well as histological changes in dentin and pulp tissue in rats. Diabetes was induced in Wistar rats (n=25) by intravenous administration of alloxan (42mg/kg). Diabetic and non-diabetic control rats were evaluated at 1, 3, 6, 9 and 12 months of follow-up. In order to evaluate the presence and progression of dental caries and periapical lesions, hemimandibles were removed and submitted to radiographical, histological, and morphometrical procedures. Dental caries were detected after radiographical and histological evaluations in diabetic group from the third month of diabetes onset, increasing gradually in frequency and severity in periods. Diabetic rats dental pulps also presented significant reduction in volume density of collagen fibers and fibroblasts at third month, parallel with a trend towards the increase in inflammatory cells volume density. Diabetic rats presented a generalized pulp tissue necrosis after 6 months of diabetes induction. Moreover, periapical lesions were not detected in control group, while these lesions were observed in all rats after 3, 6, 9, and 12 months of diabetes induction. Uncontrolled diabetes seems to trigger the loss of tooth structure, associated to histological dental changes and mediates its evolution to progressive severe pulp and periapical lesions in rats. Therefore, diabetes may be considered a very important risk factor regarding alterations in dental pulp, development of dental caries, and periapical lesions.