Protease-activated receptor type 2 activation downregulates osteogenesis in periodontal ligament stem cells

Abstract Protease-activated receptor-2 (PAR2) is associated with the pathogenesis of many chronic diseases with inflammatory characteristics, including periodontitis. This study aimed to evaluate how the activation of PAR2 can affect the osteogenic activity of human periodontal ligament stem cells (PDLSCs) in vitro. PDLSCs collected from three subjects were treated in osteogenic medium for 2, 7, 14, and 21 days with trypsin (0.1 U/mL), PAR2 specific agonist peptide (SLIGRL-NH2) (100 nM), and PAR2 antagonist peptide (FSLLRY-NH2) (100 nM). Gene (RT-qPCR) expression and protein expression (ELISA) of osteogenic factors, bone metabolism, and inflammatory cytokines, cell proliferation, alkaline phosphatase (ALP) activity, alizarin red S staining, and supernatant concentration were assessed. Statistical analysis of the results with a significance level of 5% was performed. Activation of PAR2 led to decreases in cell proliferation and calcium deposition (p < 0.05), calcium concentration (p < 0.05), and ALP activity (p < 0.05). Additionally, PAR2 activation increased gene and protein expression of receptor activator of nuclear factor kappa-Β ligand (RANKL) (p < 0.05) and significantly decreased the gene and protein expression of osteoprotegerin (p <0. 05). Considering the findings, the present study demonstrated PAR2 activation was able to decrease cell proliferation, decreased osteogenic activity of PDLSCs, and upregulated conditions for bone resorption. PAR2 may be considered a promising target in periodontal regenerative procedures.

Protease-activated receptor type 1 (PAR1) increases CEMP1 gene expression through MAPK/ERK pathway

Abstract: PAR1 is a G-coupled protein receptor that regulates several cellular metabolism processes, including differentiation and proliferation of osteogenic and cementogenic related cells and our group previously demonstrated the regenerative potential of PAR1 in human periodontal ligament stem cells (hPDLSCs). In this study, we hypothesized that PAR1 regulates the cementogenic differentiation of hPDLSCs. Our goal was to identify the intracellular signaling pathway underlying PAR1 activation in hPDSLC differentiation. hPDLSCs were isolated using the explant technique. Cells were cultured in an osteogenic medium (OST) (α-MEM, 15% fetal bovine serum, L-glutamine, penicillin, streptomycin, amphotericin B, dexamethasone, and beta-glycerophosphate). The hPDLSCs were treated with a specific activator of PAR1 (PAR1 agonist) and blockers of the MAPK/ERK and PI3K pathways for 2 and 7 days. The gene expression of CEMP1 was assessed by RT-qPCR. The activation of PAR1 by its agonist peptide led to an increase in CEMP1 gene expression when compared with OST control. MAPK/ERK blockage abrogated the upregulation of CEMP1 gene expression induced by PAR1 agonist (p < 0.05). PI3K blockage did not affect the gene expression of CEMP1 at any experimental time (p > 0.05). We concluded that CEMP1 gene expression increased by PAR1 activation is MAPK/ERK-dependent and PI3K independent, suggesting that PAR1 may regulate cementogenetic differentiation of hPDLSCs.

Clinical and microbiological evaluation of non-surgical periodontal therapy in obese and non-obese individuals with periodontitis: a 9-month prospective longitudinal study

Abstract Objective Obesity is a chronic disease that negatively affects an individual's general and oral health. The present study aimed to compare the clinical and microbiological effects of non-surgical periodontal therapy with the full mouth disinfection (FMD) protocol on obese and non-obese individuals at 9 months post-therapy. Methodology This clinical study was first submitted and approved by the Ethics Committee. Fifty-five obese patients and 39 non-obese patients with periodontitis were evaluated. The full-mouth periodontal clinical parameters, clinical attachment level (CAL), probing depth (PD), gingival index (GI), and plaque index (PI), were monitored at baseline, 3, 6, and 9 months after periodontal treatment with full mouth disinfection (FMD) protocol. The mean count of Tannerella forsythia , Porphyromonas gingivalis , Treponema Denticola , and Aggregatibacter actinomycetemcomitans was determined by quantitative polymerase chain reaction on subgingival biofilm samples. Demographic data were assessed by Chi-square test. For clinical and microbiological parameters, two-factor repeated-measures ANOVA was used. Results In both groups, periodontal therapy using the one-stage full-mouth disinfection protocol significantly improved CAL, PD, GI, and PI (p<0.05). Obese and non-obese patients equally responded to non-surgical periodontal therapy (p>0.05). Microbial count found no major differences (p>0.05) between obese and non-obese individuals who had undergone non-surgical periodontal therapy. Conclusions Obesity did not affect the clinical and microbiological outcomes of non-surgical periodontal therapy.

Effect of magnification on root coverage surgery: a systematic review

Root coverage surgery can be performed in patients with gingival recession to cover the exposed root aiming to control hypersensitivity and promotes better aesthetic. Optical magnification has been proposed as a refinement in this surgical technique to increase root coverage. This approach may lead to enhanced soft tissue stability, less post-operative discomfort, better predictability and esthetic appearance. Aim: This systematic review aimed to evaluate the effectiveness of magnification on root coverage surgery when compared to procedures performed without magnification. Methods: Randomized controlled trials with a follow-up of at least 6 months that compared surgeries for root coverage performed under optic magnification versus conventional (macro) root coverage surgery were screened. The primary outcome was mean root coverage (mm) (MRC) and secondary outcomes were percentage of root coverage (PRC) and complete root coverage (CRC). Results: Of 569 papers relevant to this review, seven were included. Meta-analysis showed that the use of magnification may favor greater PRC (7.38%, 95% CI 3.66-11.09). Conclusion: Magnification can increase PRC in root coverage surgeries. More randomized trials with the use of magnification may be necessary to verify if this benefit is clinically relevant, in order to justify the use of this device

Comparison of two commercial dentifrices in the reduction of gingivitis and plaque: a pilot study / Comparação de dois dentífricos comerciais na redução da gengivite e da placa bacteriana: um ensaio clínico randomizado controlado

Objectives: Chlorhexidine (CHX) and triclosan are the most used chemical agents in dentistry. However, the combination of these products has never been tested. We hypothesize that the addition of CHX to a triclosan dentifrice formulation may offer additional benefits in the reduction of plaque and gingivitis. Thus, the aim of this study was to compare a commercial dentifrice containing 0.05% chlorhexidine and 0.3% triclosan, with conventional toothpaste containing 0.3% triclosan, in the treatment of gingivitis and plaque reduction. Material and Methods: Thirty volunteers were randomly assigned to receive a dentifrice containing 0.05% CHX and 0.3% triclosan (CHX/ triclosan group) or a dentifrice containing basically 0.3% triclosan (Triclosan group). Subjects received clinical evaluation such as gingival index (GI) and plaque index (PI) at baseline, 30 and 60 days. Results: After 60 days, both treatments led to a significant improvement in GI and PI. There was no significant difference between groups as regards change in GI and PI (p>0.05). Conclusion: The combination of 0.05% CHX with 0.3% triclosan did not offer further benefits to gingival inflammation and plaque control when compared with a dentifrice containing 0.3% triclosan. (AU)

Objetivos: Clorexidina e triclosan são os agentes químicos mais utilizados em odontologia. No entanto, a combinação desses produtos nunca foi testada. Nós levantamos a hipótese de que a adição de clorexidina a um dentifrício contendo triclosan pode oferecer benefícios adicionais na redução de placa e gengivite. Assim, o objetivo deste estudo foi comparar um dentífrico comercial contendo 0,05% de clorhexidina e 0,3% de triclosan, com creme dental convencional contendo 0,3% de triclosan, no tratamento de gengivite e redução da placa. Material e Métodos: trinta voluntários foram distribuídos aleatoriamente para receber um dentifrício contendo 0,05% de clorexidina e 0,3% de triclosan ou um dentifrício contendo basicamente 0,3% de triclosan. Os indivíduos receberam avaliação clínica de índice gengival (IG) e índice de placa (IP) nos tempos 0, 30 e 60 dias. Resultados: após 60 dias, ambos os tratamentos levaram a uma melhora significativa no IG e IP. Não houve diferença significativa entre os grupos no que se refere à mudança no IG e IP (p> 0,05). Conclusão: A combinação de 0,05% de Clorexidina com 0,3% de triclosan não ofereceu benefícios adicionais para a redução de inflamação gengival e o controle da placa quando comparado com um dentifrício contendo 0,3% de triclosan (AU)