Obesity Modifies the Proteomic Profile of the Periodontal Ligament.

This study aimed to assess the obesity effects on the proteomic profile of the periodontal ligament of rats submitted to obesity induction by a high-fat diet. Eight Holtzman rats were divided into control (n = 3) and obese (n = 5) groups. The maxillae were histologically processed for laser capture microdissection of the periodontal ligament of the first maxillary molars. Peptide mixtures were analyzed by LC-MS/MS. A total of 1379 proteins were identified in all groups. Among them, 335 (24.30%) were exclusively detected in the obese group, while 129 (9.35%) proteins were uniquely found in the control group. Out of the 110 (7.98%) differentially abundant proteins, 10 were more abundant and 100 had decreased abundance in the obese group. A gene ontology analysis showed some proteins related to obesity in the "extracellular exosome" term among differentially identified proteins in the gene ontology cellular component terms Prelp, Sec13, and Sod2. These three proteins were upregulated in the obese group (p < 0.05), as shown by proteomic and immunohistochemistry analyses. In summary, our study presents novel evidence that the proteomic profile of the periodontal ligament is altered in experimental obesity induction, providing a list of differentially abundant proteins associated with obesity, which indicates that the periodontal ligament is responsive to obesity.

Cementocyte alterations associated with experimentally induced cellular cementum apposition in Hyp mice.

BACKGROUND: Cellular cementum, a mineralized tissue covering apical tooth roots, grows by apposition to maintain the tooth in its occlusal position. We hypothesized that resident cementocytes would show morphological changes in response to cementum apposition, possibly implicating a role in cementum biology. METHODS: Mandibular first molars were induced to super-erupt (EIA) by extraction of maxillary molars, promoting rapid new cementum formation. Tissue and cell responses were analyzed at 6 and/or 21 days post-procedure (dpp). RESULTS: High-resolution micro-computed tomography (micro-CT) and confocal laser scanning microscopy showed increased cellular cementum by 21 dpp. Transmission electron microscopy (TEM) revealed that cementocytes under EIA were 50% larger than control cells, supported by larger pore sizes detected by micro-CT. Cementocytes under EIA displayed ultrastructural changes consistent with increased activity, including increased cytoplasm and nuclear size. We applied EIA to Hyp mutant mice, where cementocytes have perilacunar hypomineralization defects, to test cell and tissue responses in an altered mechanoresponsive milieu. Hyp and WT molars displayed similar super-eruption, with Hyp molars exhibiting 28% increased cellular cementum area versus 22% in WT mice at 21 dpp. Compared to control, Hyp cementocytes featured well-defined, disperse euchromatin and a thick layer of peripherally condensed heterochromatin in nuclei, indicating cellular activity. Immunohistochemistry (IHC) for cementum markers revealed intense dentin matrix protein-1 expression and abnormal osteopontin deposition in Hyp mice. Both WT and Hyp cementocytes expressed gap junction protein, connexin 43. CONCLUSION: This study provides new insights into the EIA model and cementocyte activity in association with new cementum formation.

Tailoring the synthesis of tantalum-based thin films for biomedical application: Characterization and biological response.

The aim of this study was to tailor the deposition parameters of magnetron sputtering to synthetize tantalum oxide (TaxOy) films onto commercially pure titanium (cpTi) surface. The structural and optical properties, morphology, roughness, elemental chemical composition and surface energy were assessed. The impact of TaxOy films on initial Streptococcus sanguinis adhesion was investigated. The morphology and spreading of pre-osteoblastic (MC3T3-E1) cells on a crystalline tantalum oxide film were evaluated. TaxOy films with estimated thickness of 600 nm and different structures (amorphous or crystalline) were produced depending on the various oxygen flow rates and parameters used. X-ray diffraction analysis revealed that the 8 O2 sccm (600 °C/400 W) group showed crystallization corresponding to the ß-Ta2O5 phase. Optical analysis showed that the 4 O2 sccm (200 °C 300 W) to 8 O2 sccm (600 °C 300 W) groups and 10 O2 sccm (200 °C 300 W) group presented regular and large-amplitude interference oscillations, suggesting high optical homogeneity of the films. The crystalline ß-Ta2O5 coating showed higher roughness and surface energy values than the other groups (P < .05) and was biocompatible. Compared with cpTi, the amorphous and crystalline tantalum oxide films did not increase bacterial adhesion (P > .05). By tailoring the deposition parameters, we synthetized a crystalline ß-Ta2O5 coating that improved titanium surface properties and positively affected cell spreading and morphology, making it a promising surface treatment for titanium-based implants.

Characterization of chemically treated Ti-Zr system alloys for dental implant application.

Materials and surfaces developed for dental implants need to withstand degradation processes that take place in the oral cavity. Therefore, the aim of the study was to develop and evaluate the topographical, mechanical, chemical, electrochemical and biological properties of Ti-xZr alloys (x = 5, 10, and 15 wt%) with two surface features (machined and double acid etched). Commercially pure titanium (cpTi) and Ti-6Al-4V alloy were used as controls. Surface characterization was performed using dispersive energy spectroscopy, X-ray diffraction, scanning electron microscopy, atomic force microscopy, profilometry and surface energy. The mechanical properties were assessed using Vickers microhardness, elastic modulus and stiffness. The electrochemical behavior analysis was conducted in a body fluid solution (pH 7.4). In addition, MC3T3-E1 cells were used to determine the impact of material and surface treatment on cell morphology by SEM analysis. Data were analyzed by two-way ANOVA and Bonferroni test (α = 0.05). Ti-Zr alloys showed lower surface roughness, elastic modulus and stiffness, as well as higher hardness and surface energy when compared to cpTi. Ti-Zr system increased the polarization resistance values and significantly decreased the capacitance, corrosion current density (icorr), and passivation current density (ipass) values. The acid treatment increased the resistance and corrosion potential of the oxide layer. SEM data analysis demonstrated that Ti-Zr alloys displayed normal cell attachment/spreading and slightly changed cell morphology in the double etched surface. In conclusion, Zr addition and surface treatment altered surface, mechanical, biological and electrochemical properties of Ti material.

Evaluation of peri-implant marginal tissues around tissue-level and bone-level implants in patients with a history of chronic periodontitis.

OBJECTIVE: To evaluate clinical and radiographic characteristics in peri-implant marginal tissues in patients with a history of chronic periodontitis, rehabilitated using tissue-level or bone-level implants. MATERIAL AND METHODS: Using a split-mouth design, 20 patients with a history of chronic periodontitis were selected and received two different implants, tissue-level group (n = 20) and the bone-level group (n = 20). Peri-implant probing depth, relative peri-implant mucosal margin position, relative peri-implant clinical attachment level, peri-implant plaque index and peri-implant bleeding on probing were evaluated at prosthesis installation, 1, 3, 6, 12 and 24 months after implant loading. Radiographic marginal bone level was evaluated at implant insertion, prosthesis installation, 6 and 24 months after implant loading. RESULTS: The mean difference of peri-implant marginal bone resorption from implant installation to 24 months in function was 0.75 ± 1.12 mm for the tissue-level group and 0.70 ± 0.72 mm for the bone-level group. No statistically significant difference was found between groups at all assessment periods for clinical and radiographic peri-implant evaluation. CONCLUSION: Under a rigid supportive therapy, both approaches performed likewise regarding clinical and radiographic parameters for rehabilitation of patients with a history of chronic periodontitis.

Three-species biofilm model onto plasma-treated titanium implant surface.

In this study, titanium (Ti) was modified with biofunctional and novel surface by micro-arc oxidation (MAO) and glow discharge plasma (GDP) and we tested the development of a three-species periodontopatogenic biofilm onto the treated commercially-pure titanium (cpTi) surfaces. Machined and sandblasted surfaces were used as control group. Several techniques for surface characterizations and monoculture on bone tissue cells were performed. A multispecies biofilm composed of Streptococcus sanguinis, Actinomyces naeslundii and Fusobacterium nucleatum was developed onto cpTi discs for 16.5h (early biofilm) and 64.5h (mature biofilm). The number of viable microorganisms and the composition of the extracellular matrix (proteins and carbohydrates) were determined. The biofilm organization was analyzed by scanning electron microscopy (SEM) and Confocal laser scanning microscopy (CLSM). In addition, MC3T3-E1 cells were cultured on the Ti surfaces and cell proliferation (MTT) and morphology (SEM) were assessed. MAO treatment produced oxide films rich in calcium and phosphorus with a volcano appearance while GDP treatment produced silicon-based smooth thin-film. Plasma treatments were able to increase the wettability of cpTi (p<0.05). An increase of surface roughness (p<0.05) and formation of anatase and rutile structures was noted after MAO treatment. GDP had the greatest surface free energy (p<0.05) while maintaining the surface roughness compared to the machined control (p>0.05). Plasma treatment did not affect the viable microorganisms counts, but the counts of F. nucleatum was lower for MAO treatment at early biofilm phase. Biofilm extracellular matrix was similar among the groups, excepted for GDP that presented the lowest protein content. Moreover, cell proliferation was not significantly affected by the experimental, except for MAO at 6days that resulted in an increased cell proliferative. Together, these findings indicate that plasma treatments are a viable and promising technology to treat bone-integrated dental implants as the new surfaces displayed improved mechanical and biological properties with no increase in biofilm proliferation.

Mineral distribution and CLSM analysis of secondary caries inhibition by fluoride/MDPB-containing adhesive system after cariogenic challenges.

OBJECTIVE: To evaluate the inhibition zone formation (IZ) and mineral distribution along the interface of adhesive systems either containing fluoride and antibacterial primer or not, after chemical and biological artificial caries challenges. METHODS: Forty-eight third molars were used. Artificial caries was developed with S. mutans in a 4mm x 4mm area of occlusal dentin surface. Carious dentin was removed and cavities were restored with Adper Scotchbond Multi-Purpose (SBM) and Clearfil Protect Bond (CPB) (n=24). Samples were submitted to secondary caries development by chemical (C) (acidic gel) or biological (B) (S. mutans culture) methods for 5 days. Four groups were tested (n=12): (1) SC (SBM+C); (2) SB (SBM+B); (3) CC (CPB+C); (4) CB (CPB+B). The IZ and outer lesion (OL) formations were analyzed by confocal laser scanning microscopy (CLSM). The distribution of calcium (Ca) and phosphorus (P) content along the interface was analyzed by micro X-ray fluorescence spectrometer by energy-dispersive (microEDX). RESULTS: The frequency of IZ formation and mean values of IZ thickness differed among the groups. The CC group presented the lowest OL depth. microEDX analysis showed that CPB had the highest mineral loss by the biological method, but the lowest mineral loss by the chemical method. SC and SB groups showed intermediate values of mineral loss. CONCLUSION: The mineral loss along the dentin/restoration interface was affected by the artificial caries method, and hybrid layer formation by adhesive systems used. The adhesive system containing fluoride and antibacterial primer did not prevent secondary caries formation.

Achieving primary closure and enhancing aesthetics with periodontal microsurgery.

The continuous search for improved surgical procedures to address gingival deformities is a consequence of an increasing demand for aesthetics in the periodontal clinical practice. Innovative techniques have been reported to help clinicians achieve predictability in root coverage. Significant progress can be attributed to the inclusion of the operative microscope in periodontal therapy, particularly in regards to obtaining primary closure. This article describes a microsurgical technique used to treat gingival recessions, showing its potential for obtaining optimal aesthetic results.

Smoking may affect root coverage outcome: a prospective clinical study in humans.

BACKGROUND: Cigarette smoking has been shown to negatively influence healing following periodontal therapeutic procedures. Therefore, the aim of this study was to evaluate the impact of smoking on clinical outcome of root coverage following subepithelial connective tissue graft (CTG) surgery. METHODS: Eighteen defects were treated in 15 patients (seven smokers and eight non-smokers) who presented canine and pre-molar Miller Class I and II recessions. CTG was performed and clinical measurements were obtained at baseline, and 30, 60, 90, and 120 days after surgery. Clinical measurements included plaque and gingival indexes, gingival recession, probing depth, clinical attachment level, gingival thickness, and keratinized tissue width. RESULTS: Intragroup analysis showed that CTG was able to promote root coverage, increase gingival thickness, and improve clinical attachment level in both groups (P < 0.05). On the other hand, intergroup analysis demonstrated that smokers presented with a lower percentage of root coverage (58.84% +/- 13.68% versus 74.73% +/- 14.72%), less clinical attachment level gain (2.54 +/- 0.79 mm versus 2.00 +/- 1.04 mm), and deeper probing depths (1.56 +/- 0.53 mm versus 2.35 +/- 0.67 mm) than non-smokers (P < 0.05). Moreover, 4 months after CTG, smokers presented more keratinized tissue compared to non-smokers (3.30 +/- 0.86 mm versus 4.50 +/- 1.16 mm) (P < 0.05). CONCLUSION: Within the limits of the present study, it can be concluded that cigarette consumption may present a negative impact on root coverage outcome by CTG and, therefore, may represent one more challenge for periodontal plastic therapy.

Attachment loss after scaling and root planing with different instruments. A clinical study.

OBJECTIVES: The aim of this study was to evaluate clinically the immediate effect of trauma from instrumentation after scaling and root planing with different instruments. MATERIAL AND METHODS: Ten subjects with moderate chronic periodontitis, presenting probing depths ranging from 3.5 to 6.5 mm on anterior teeth, upper and/or lower, were selected. Teeth were randomly assigned to one of the following groups: MC group--scaled and planed with Gracey mini-curettes (MiniFive); CC group--scaled and planed with Gracey conventional curettes. The selected teeth were probed with a computerized electronic probe, guided by an occlusal stent, and then subjected to scaling and root planing. Immediately following instrumentation, teeth were probed again. The difference between relative attachment level (RAL) immediately before and after instrumentation was considered as trauma from instrumentation. RESULTS: Intra-group analysis revealed statistically significant differences between RAL immediately before and after instrumentation in both groups (0.68 +/- 0.32 for MC group; and 0.83 +/- 0.41 for CC group--p < 0.05). However, inter-group analysis did not show a statistically significant difference in trauma from instrumentation caused by the different instruments. CONCLUSIONS: Within the limits of this study, it was concluded that root instrumentation causes an average trauma from instrumentation of 0.76 mm with no differences between the tested instruments.

Clinical and radiographic evaluation of guided tissue regeneration in the treatment of class II furcation defects. A randomized clinical trial.

PURPOSE: To evaluate the treatment outcomes after guided tissue regeneration (GTR) with a bioabsorbable membrane in Class II furcation defects in mandibular molars. The open flap debridement (OFD) was used as the control. METHODS: Nine patients, with two comparable Class II furcation defects were included in the study. After initial preparation, the defects were randomly assigned in each patient to either GTR-group or OFD-group. Clinical parameters and standardized radiographs were obtained at baseline and 6 months after the surgeries. The radiographs were analyzed by subtraction radiography. RESULTS: Comparing baseline to 6-month results, both groups showed statistically significant probing depth reduction (PD), horizontal clinical attachment level (CAL-h) gain, and increase in gingival recession (GR). The vertical clinical attachment level (CAL-v) gain was statistically significant only for the OFD-group. Comparing the two treatments, no statistically significant differences were found in PD reduction (GTR: 1.67 mm; OFD: 2.51 mm, P = 0.26), CAL-v gain (GTR: 0.62 mm; OFD: 1.16 mm, P= 0.37), and GR increase (GTR: 1.04 mm; OFD: 1.24 mm, P = 0.31). GTR provided complete closure of the furcation defect in two sites and superior horizontal clinical attachment level gain (GTR: 2.27 mm; OFD: 1.01 mm, P = 0.05). Subtraction radiography showed significant difference in bone height change between GTR-group and OFD-group (-0.14 mm and 0.86 mm, respectively; P = 0.028) at 6 months.

Coronally positioned flap with or without enamel matrix protein derivative for the treatment of gingival recessions.

PURPOSE: To evaluate, histometrically, the healing of gingival recessions treated by coronally positioned flaps associated with enamel matrix protein derivative (EMD-Group) and to compare it to that obtained with coronally positioned flaps alone (CPF-Group). METHODS: Five mongrel dogs were used. Gingival recessions were surgically created on the buccal aspect of the upper cuspids. The defects (5 x 7 mm) were exposed to plaque accumulation for 3 months. After a preparation period, the contralateral defects were randomly assigned to each group. After 3 months of healing, the dogs were sacrificed and the blocks were processed. The histometric parameters evaluated included: gingival recession, length of epithelium, new connective tissue attachment and new bone. RESULTS: The gingival recession was -0.1 +/- 0.2 mm for the EMD-Group and -0.8 +/- 1.3 mm for the CPF-Group (P = 0.17). The extension of the epithelium was 1.2 +/- 1.0 mm for the EMD-Group and 1.3 +/- 0.7 mm for the CPF-Group (P = 0.89). The new connective tissue attachment was 4.8 +/- 0.7 in the EMD-Group and 4.0 +/- 1.4 in the CPF-Group (P = 0.22). The new bone was 0.1 +/- 1.8 mm and -0.5 +/- 1.4 mm in the EMD-Group and CPF-Group, respectively (P = 0.50). Histologically, the defect coverage observed was 98.2% for the EMD-Group and 85.8% for the CPF-Group.

Clinical study of guided bone regeneration and/or bone grafts in the treatment of ligature-induced peri-implantitis defects in dogs

O presente estudo avaliou, clinicamente, a resposta do tecido ósseo após o tratamento de defeitos resultantes da peri-implantite induzida por ligaduras em cães. Cinco cães foram utilizados. Os pré molares inferiores foram extraídos de ambos os lados da mandíbula. Após três meses, os intermediários foram conectados aos implantes e a peri-implantite induzida através da colocação de ligaduras em posição submarginal. Um mês mais tarde, as ligaduras e os intermediários foram removidos e os defeitos ósseos resultantes foram aleatoriamente divididos entre os seguintes tratamentos: descontaminação (DE), descontaminação associada a regeneração óssea guiada (GBR), decontaminação associada ao enxerto ósseo (GB) e descontaminação associada a regeneração óssea guiada e ao enxerto ósseo (GBR+BG). Os defeitos ósseos peri-implantares foram clinicamente avaliados antes e após 5 meses do tratamento. Os resultados demonstraram uma maior porcentagem de preenchimento ósseo vertical para GBR+BG (27,77 ± 14,07) seguido por GBR (21,78 ± 16,19), BG (21,26 ± 6,87), DE (14,03 ± 5,6). Entretanto, a análise de variância não detectou diferenças estatísticas em qualquer um dos tratamentos propostos (P=0,265). Assim, dentro dos limites do presente trabalho, concluiu-se que não há diferença entre os tratamentos investigados.

Escovaçäo dental associada ao gel de clorexidina: no tratamento da gengivite marginal / Marginal gingivitis treatment with tooth brushing associated with clorexidina gel

O objetivo deste estudo foi observar o efeito antimicrobiano de um gel experimental de clorhexidina a 1 por cento quando associado à escovaçäo dentária, na reduçäo da placa bacteriana supragengival e da gengivite marginal, quando comparado à um placebo. Foi realizado um estudo paralelo, duplo cego, de 21 dias de duraçäo, em 20 pacientes aleatoriamente divididos em dois grupos experimentais balanceados (teste e controle), os quais foram orientados sobre H.B e que deveriam escovar os dentes com o gel designado, duas vezes ao dia. Foram realizados os índices de placa e de sangramento gengival em períodos estabelecidos de 0, 7, 14 e 21 dias. Os resultados mostraram após 21 dias, uma reduçäo estatisticamente (p<0,05) da placa e da gengivite em ambos os grupos, sendo que os mesmos näo diferiram entre si em nenhum dos períodos avaliados. Concluiu-se que a utilizaçäo do gel de clorexidina a 1 por cento näo estaria indicada para indivíduos capazes de controlar adequadamente placa bacteriana através das instruçöes de higiene bucal e da escovaçäo

Necessidade de tratamento periodontal avaliada pelo CPITN e sua relaçäo com a qualidade de acabamento cervical das restauraçöes / Need for periodontal treatment evaluated through CPITN and its relation to the quality of the cervical margin of restorations

Irregularidades do acabamento cervical de restauraçöes constituem fatores de retençäo de placa bacteriana, dificultando o controle de placa pelos procedimentos habituais de higiene bucal, favorecendo o desenvolvimento da doença periodontal. O objetivo deste estudo foi avaliar as condiçöes periodontais e a necessidade de tratamento em funçäo do acabamento cervical de restauraçöes dentais. Foram examinados 367 dentes restaurados com classe II e V de amálgama, classe III em resina, restauraçäo metálica fundida e prótese unitárias. Utilizando-se sonda periodontal (OMS), verificou-se a posiçäo do término da restauraçäo (supragengival, subgengival ou ao nível da margem gengival); a qualidade das restauraçöes (falta ou excesso de material restaurador) e a presença de grau 2 do CPITN. Após a análise dos dados, foi possível concluir que: 1) o término supragengival ofereceu a melhor adaptaçäo marginal e a menor freqüência de grau 2 do CPITN; 2) a falta ou excesso de material restaurador favorecem o desenvolvimento de grau 2, independentemente do material utilizado e 3) nos términos subgengivais, foi maior a freqüência de adaptaçäo marginal incorreta, principalmente casos de excesso de material restaurador, sendo estes casos de maior ocorrência de grau 2 do CPITN

A influência do sexo e da idade na prevalência de bolsas periodontais / The influence of gender and age on the prevalence of periodontal pockets

Este trabalho teve como objetivo avaliar a influência dos fatores de risco na prevalência de bolsas periodontais em pacientes atendidos na clínica do terceiro e quarto anos da Faculdade de Odontologia de Piracicaba - Unicamp. Foram avaliados 100 pacientes através do levantamento dos dados contidos nas fichas clínico-anamnésicas, sendo consideradas bolsas de profundidade: 3 mm, 5 mm, 7 mm e 10mm, de acordo com o sistema diagnóstico WS (SALLUM; SALLUM, 1996). Os resultados foram comparados entre as profundidades de sondagem e as variáveis idade, sexo, bem como sua distribuiçäo por sextantes. Observou-se maior prevalência de bolsas periodontais no sexo masculino, bem como maior profundidade de sondagem em pacientes acima de 31 anos. A distribuiçäo de bolsas periodontais entre os sextantes foi homogênea