Efeito de uma única sessão de controle de placa supragengival nos parâmetros clínicos e bioquímicos da periodontite crônica

Supragingival plaque control is a requisite for the success of any periodontal procedure. However, little is know about the effect of this procedure alone on periodontitis. The aim of this study was to determine the effect of supragingival plaque control on clinical and biochemical parameters of chronic periodontitis. Twenty-five subjects exhibiting at least 4 pockets >; 5mm, non-smokers and with no relevant systemic diseases, were selected for the study. The clinical and biochemical assessments were done before and 21 days after removal of plaque retentive factors, extraction of affected teeth and instruction in oral hygiene. The statistical analysis was done with the Student paired t-test (pO objetivo deste estudo foi avaliar o efeito do controle de placa supragengival sobre os parâmetros clínicos e bioquímicos da periodontite crônica. Foram selecionados 25 pacientes apresentando pelo menos 4 sítios com profundidade de sondagem >; 5 mm, não fumantes e sem alterações sistêmicas relevantes. A avaliação clínica e bioquímica foi feita antes e 21 dias após a remoção dos fatores retentivos de placa, exodontia dos dentes condenados e instrução de higiene bucal. A análise estatística foi feita através do teste t de Student pareado (

RG108 increases NANOG and OCT4 in bone marrow-derived mesenchymal cells through global changes in DNA modifications and epigenetic activation. RG108 increases NANOG and OCT4 through epigenetic activation.

Human bone marrow-derived mesenchymal stem cells (hBMSCs) are important for tissue regeneration but their epigenetic regulation is not well understood. Here we investigate the ability of a non-nucleoside DNA methylation inhibitor, RG108 to induce epigenetic changes at both global and gene-specific levels in order to enhance mesenchymal cell markers, in hBMSCs. hBMSCs were treated with complete culture medium, 50 μM RG108 and DMSO for three days and subjected to viability and apoptosis assays, global and gene-specific methylation/hydroxymethylation, transcript levels' analysis of epigenetic machinery enzymes and multipotency markers, protein activities of DNMTs and TETs, immunofluorescence staining and western blot analysis for NANOG and OCT4 and flow cytometry for CD105. The RG108, when used at 50 μM, did not affect the viability, apoptosis and proliferation rates of hBMSCs or hydroxymethylation global levels while leading to 75% decrease in DNMTs activity and 42% loss of global DNA methylation levels. In addition, DNMT1 was significantly downregulated while TET1 was upregulated, potentially contributing to the substantial loss of methylation observed. Most importantly, the mesenchymal cell markers CD105, NANOG and OCT4 were upregulated being NANOG and OCT4 epigenetically modulated by RG108, at their gene promoters. We propose that RG108 could be used for epigenetic modulation, promoting epigenetic activation of NANOG and OCT4, without affecting the viability of hBMSCs. DMSO can be considered a modulator of epigenetic machinery enzymes, although with milder effect compared to RG108

Necessidade de tratamento periodontal avaliada pelo CPITN e sua relação com a qualidade de acabamento cervical das restaurações

Irregularities of the cervical margin of restorations facilitate the retention of bacterial plaque, hindering plaque control through the habitual procedures of oral hygiene and favoring the development of periodontal disease. The aim of this study was to evaluate the periodontal condition and treatment needs (applying CPITN) in relation to the cervical margin of dental restorations. Three hundred and sixty-seven teeth with class II and V cavities restored with amalgam, class III cavities restored with composite resin, cast metal restorations and unitary prostheses were examined. With a WHO periodontal probe, the position of the cervical margins of restorations was verified (supragingival, subgingival or at the gingival margin level); the presence of defects (lack or excess of restoring material) and the presence of score 2 of CPITN were also assessed. After the analysis of the data, it was possible to conclude that: 1) supragingival margins offered the best marginal adaptation and the lowest frequency of score 2; 2) both the lack and the excess of restoring material favor the development of score 2, despite the utilized material and 3) in subgingival margins, incorrect marginal adaptation was the most frequent event, mainly due to excess of restoring material, and in these cases there was higher frequency of score 2 of CPITN.Irregularidades do acabamento cervical de restaurações constituem fatores de retenção 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 condições periodontais e a necessidade de tratamento em função do acabamento cervical de restaurações dentais. Foram examinados 367 dentes restaurados com classes II e V de amálgama, classe III em resina, restauração metálica fundida e próteses unitárias. Utilizando-se sonda periodontal (OMS), verificou-se a posição do término da restauração (supragengival, subgengival ou ao nível da margem gengival); a qualidade das restaurações (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 adaptação 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 adaptação marginal incorreta, principalmente casos de excesso de material restaurador, sendo estes casos de maior ocorrência de grau 2 do CPITN

Impact of supragingival therapy on subgingival microbial profile in smokers versus non-smokers with severe chronic periodontitis

The aim of this study was to assess subgingival microbiological changes in smokers versus non-smokers presenting severe chronic periodontitis after supragingival periodontal therapy (ST).Non-smokers (n=10) and smokers (n=10) presenting at least nine teeth with probing pocket depth (PPD) (≥5 mm), bleeding on probing (BoP), and no history of periodontal treatment in the last 6 months were selected. Clinical parameters assessed were plaque index (PI), BoP, PPD, relative gingival margin position (rGMP) and relative clinical attachment level (rCAL). Subgingival biofilm was collected before and 21 days after ST. DNA was extracted and the 16S rRNA gene was amplified with the universal primer pair, 27F and 1492R. Amplified genes were cloned, sequenced, and identified by comparison with known 16S rRNA sequences. Statistical analysis was performed by Student's t and Chi-Square tests (α=5%).Clinically, ST promoted a significant reduction in PI and PPD, and gain of rCAL for both groups, with no significant intergroup difference. Microbiologically, at baseline, data analysis demonstrated that smokers harbored a higher proportion of Porphyromonas endodontalis, Bacteroidetes sp., Fusobacterium sp. and Tannerella forsythia and a lower number of cultivated phylotypes (p<0.05). Furthermore, non-smokers featured significant reductions in key phylotypes associated with periodontitis, whereas smokers presented more modest changes.Within the limits of the present study, ST promoted comparable clinical improvements in smokers and non-smokers with severe chronic periodontitis. However, in smokers, ST only slightly affected the subgingival biofilm biodiversity, as compared with non-smokers

Experimental and clinical studies on regenerative periodontal therapy

The recognition of a periodontal therapy as a regenerative procedure requires the demonstration of new cementum, periodontal ligament, and bone coronal to the base of the defect. A diversity of regenerative strategies has been evaluated, including root surface conditioning, bone grafts and bone substitute materials, guided tissue regeneration, enamel matrix proteins, growth/differentiation factors, combined therapies and, more recently, tissue‐engineering approaches. The aim of this chapter of Periodontology 2000 is to review the research carried out in Latin America in the field of periodontal regeneration, focusing mainly on studies using preclinical models (animal models) and randomized controlled clinical trials. This review may help clinicians and researchers to evaluate the current status of the therapies available and to discuss the challenges that must be faced in order to achieve predictable periodontal regeneration in clinical practice791225

Nicotine And Bone Density Around Titanium Implants: A Histometric Study In Rabbits.

This study investigated the influence of nicotine on bone density around titanium implants inserted in rabbits. Thirty-two New Zealand rabbits were included. After anesthesia, the tibiae surfaces were exposed and two screw-shaped, commercially available, pure titanium implants of 7.0 mm in length and 3.75 mm in diameter were placed bilaterally. A total of 128 implants were inserted: 64 blasted with Al2O3 particles (group 1) and 64 with a machined surface finish (group 2). The animals were randomly assigned to one of four treatment subgroups, and daily subcutaneous injections of nicotine were administered. After 42 days, the animals were killed and undecalcified sections were prepared. The bone density was measured in the cortical passage of the implant. Statistical analysis (two-way analysis of variance) revealed no significant difference neither regarding the effect of nicotine nor the effect of surface design on bone density around the implants (P > 0.05). Within the limits of the present study, it can be assumed that daily nicotine administration may not statistically influence bone density around titanium implants.11176-8

Attachment Loss After Scaling And Root Planing With Different Instruments. A Clinical Study.

The aim of this study was to evaluate clinically the immediate effect of trauma from instrumentation after scaling and root planing with different instruments. 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. 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. 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.3112-

Coronally Positioned Flap With Or Without Enamel Matrix Protein Derivative For The Treatment Of Gingival Recessions.

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). 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. 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.16287-9

The effect of one session of supragingival plaque control on clinical and biochemical parameters of chronic periodontitis Efeito de uma única sessão de controle de placa supragengival nos parâmetros clínicos e bioquímicos da periodontite crônica

Supragingival plaque control is a requisite for the success of any periodontal procedure. However, little is know about the effect of this procedure alone on periodontitis. The aim of this study was to determine the effect of supragingival plaque control on clinical and biochemical parameters of chronic periodontitis. Twenty-five subjects exhibiting at least 4 pockets > 5mm, non-smokers and with no relevant systemic diseases, were selected for the study. The clinical and biochemical assessments were done before and 21 days after removal of plaque retentive factors, extraction of affected teeth and instruction in oral hygiene. The statistical analysis was done with the Student paired t-test (p<0,05) and demonstrated a reduction on the percentage of sites with bleeding on probing from 42.72 ± 15.83 to 35.87 ± 13.30 (p=0.002). Reduction in probing depth was detected on anterior teeth (initial/final mean: 2.88 mm/2.78 mm; p=0.01) and interproximal sites (initial/final mean: 3.80 mm/3.65 mm; p=0.001). There was an increase from 66.81% to 68.65% in the number of sites with probing depth of 1 to 3mm and a decrease from 26.21% to 24.17% in those with probing depth of 4 to 6mm. The BAPNA results showed a decrease from 51.44 ± 20.78 to 38.64 ± 12.34 (p=0.04). This study demonstrated that supragingival plaque control provides a reduction in gingival inflammation and alterations in the subgingival microflora detected by the BAPNA test.<br>O objetivo deste estudo foi avaliar o efeito do controle de placa supragengival sobre os parâmetros clínicos e bioquímicos da periodontite crônica. Foram selecionados 25 pacientes apresentando pelo menos 4 sítios com profundidade de sondagem > 5 mm, não fumantes e sem alterações sistêmicas relevantes. A avaliação clínica e bioquímica foi feita antes e 21 dias após a remoção dos fatores retentivos de placa, exodontia dos dentes condenados e instrução de higiene bucal. A análise estatística foi feita através do teste t de Student pareado (p<0,05) e demonstrou redução da porcentagem de sítios com sangramento à sondagem de 42,72 ± 15,83 para 35,87 ± 13,30 (p=0,002). Redução na profundidade de sondagem foi observada nos dentes anteriores (média inicial/final: 2,88 mm/2,78 mm; p=0,01) e faces interproximais (média inicial/final: 3,80 mm/3,65 mm; p=0,001). Houve aumento de 66,81% para 68,65% (p=0,03) no número de sítios com profundidade de sondagem de 1 a 3 mm e redução de 26,21% para 24,17% (p=0,04) nos de 4 a 6 mm. O valor do BAPNA apresentou redução de 51,44 ± 20,78 para 38,64 ± 12,34 (p=0,04). Baseado nesses achados pôde-se concluir que o controle de placa supragengival tem efeitos benéficos, principalmente relacionados à redução da inflamação gengival e da atividade de enzima tipo tripsina no biofilme subgengival (BAPNA)

Enamel Matrix Protein Derivative And/or Synthetic Bone Substitute For The Treatment Of Mandibular Class Ii Buccal Furcation Defects. A 12-month Randomized Clinical Trial.

This study aims to clinically evaluate the treatment of mandibular class II furcation defects with enamel matrix derivative (EMD) and/or a bone substitute graft made of β-tricalcium phosphate/hydroxyapatite (βTCP/HA). Forty-one patients, presenting a mandibular class II buccal furcation defect, probing pocket depth (PPD) ≥4 mm and bleeding on probing, were included. They were randomly assigned to the groups: 1-EMD (n = 13); 2-βTCP/HA (n = 14); 3-EMD + βTCP/HA (n = 14). Plaque index (PI), gingival index (GI), relative gingival margin position (RGMP), relative vertical and horizontal attachment level (RVCAL and RHCAL), and PPD were evaluated at baseline and 6 and 12 months. The mean horizontal clinical attachment level gain was considered the primary outcome variable. No significant intragroup differences were observed for RGMP, but significant changes were observed for RVCAL, RHCAL, and PPD for all groups (p < 0.05). After 12 months, the mean horizontal clinical attachment level gain was 2.77 ± 0.93 mm for EMD, 2.64 ± 0.93 mm for βTCP/HA, and 2.93 ± 0.83 mm for EMD + βTCP/HA, with no significant differences among the groups. At the end of the study, 85.3 % of the sites were partially closed; however, no complete closure was observed. EMD + βTCP/HA does not provide a significant advantage when compared to the isolated approaches. All three tested treatments promote significant improvements and partial closure of class II buccal furcation defects. Based on its potential to induce periodontal regeneration, EMD may be considered an attractive option for this type of defect, but complete closure remains an unrealistic goal. The partial closure of buccal furcation defects can be achieved after the three tested approaches. However, the combined treatment does not provide a significant benefit when compared to the isolated approaches