Journal of Applied Oral Science最新文献

Guided bone regeneration (GBR) is an alternative treatment for craniofacial bone defects reconstruction through membrane barrier adaptation, such as demineralized dentin material membrane (DDMM). DDMM is used as a substitute for GBR material, which aligns with Green Economy principles, it has a good biological osteoinductive and osteoconductive effects, and its structure resembles bones. The balance of bone remodeling when experiencing craniofacial defects will be altered and allow changes to resorption activity, so the mechanisms of osteoclastogenesis and bone resorption are vital.

Objective: this article aims to analyze the expression of TNF-α, RANKL, and osteoclast cells count after application of DDMM as GBR in mandibular bone defects.

Methodology: this is an experimental study with a post-test only control group design, which began with the randomization of 120 rats into five groups: K(-), without membrane implantation; K(+), PPCM; P1, DDMM; P2, DDMM + bone graft; P3, PPCM + bone graft. The expression of TNF-α, RANKL, and osteoclast cells count were observed, followed by analysis using a one-way ANOVA and post hoc Tukey HSD comparison test.

Results: there were significant differences in the expression of TNF-α, RANKL, and osteoclast cells count in all study groups (p=0.000). TNF-α showed a decreasing difference with the highest expression in the K(-) group on day 3 of 12.00±2.16. RANKL expression increased on day 14 and decreased on day 21 in all groups. The osteoclast cells count generally showed a critical period with the highest increase in the K(-) group on day 14 of 73.00±0.00.

Conclusion: DDMM has the potential to be a superior membrane substitute compared to PPCM as GBR in alternative treatment for craniofacial bone defects reconstruction.

Background: Past studies have indicated links between specific inflammatory proteins in the bloodstream and temporomandibular disorders (TMDs). Nonetheless, there remains the need for further solid research pinpointing the exact causes behind these associations. This Mendelian randomization (MR) study aims to examine the association between 91 circulating inflammatory proteins and TMDs.

Methodology: The most comprehensive genome-wide association studies available for circulating inflammatory proteins and TMDs was used in this two-sample MR analysis. The association between genetic predispositions to TMDs and levels of circulating inflammatory proteins was explored by various methods, including inverse variance weighted, MR-Egger, weighted median, simple mode, weighted mode, and MR-PRESSO techniques. To evaluate the reliability of these findings, sensitivity analyses such as Cochran's Q test, the MR-Egger intercept test, and a leave-one-out approach were conducted.

Results: Findings indicated significant links between lower levels of circulating CCL4 (odds ratio, OR: 0.9241, 95% confidence interval, CI: 0.8679-0.984, p=0.0138), IL-20 (OR: 0.8615, 95%CI: 0.7566-0.9808, p=0.0243), and TWEAK (OR: 0.8702, 95%CI: 0.7634-0.992, p=0.0375) and an increased risk of TMDs, according to the inverse variance weighted method. Conversely, a higher level of S100A12 in the blood stream was associated with an increased risk of TMDs (OR: 1.1368, 95%CI: 1.0134-1.2752, p=0.0286). Sensitivity analyses confirmed the stability of these outcomes.

Conclusion: This study suggests that reduced levels of CCL4, IL-20, and TWEAK are associated with a higher risk of TMDs, alongside an increased risk of TMDs connected to elevated levels of S100A12.

Objective: Submandibular salivary gland inflammation has been suggested as one of the mechanisms underlying impaired salivary secretion associated with sleep deprivation (SD). However, whether the salivary inflammatory response occurs to the same extent in paradoxical sleep deprivation with or without sleep recovery remains unknown. This study evaluated the extent to which inflammation influences salivary impairments associated with paradoxical sleep deprivation with or without sleep recovery.

Methodology: Male Wistar rats were randomly assigned into three groups as control, partial SD (PSD) with sleep recovery for four hours a day and total SD (TSD). Paradoxical SD was carried out for seven days in the SD groups, after which saliva, blood, and submandibular gland samples were taken. Levels of interleukin-6 (IL-6), tumour necrosis factor-alpha (TNF-α), and nitrite were determined in saliva, serum, and the submandibular salivary gland. Leucocyte count and neutrophil-lymphocyte ratio were determined in all groups. One-way ANOVA and the Tukey's post hoc tests were used for data analysis. P-values < 0.05 were considered statistically significant.

Results: Levels of TNF-α, IL-6, and nitrite in the submandibular salivary glands were significantly higher in the TSD groups (p=0.04,p<0.001, p=0.03, respectively) than in the control. Saliva level of TNF-α was higher in the PSD and TSD groups (p=0.003 and p=0.01 respectively) than in the control. Neutrophil-lymphocyte ratio was significantly higher in both PSD and TSD groups than in the control (p<0.01 for both).

Conclusion: While total SD produced higher inflammatory response in the submandibular salivary gland, four-hour sleep recovery ameliorated this impact. This finding suggests that sleep recovery is crucial to improve inflammatory salivary gland dysfunction induced by sleep deprivation.

Objectives: Considering the fact that resin infiltrants lack antibacterial activity, this study assessed the influence of the quaternary ammonium monomer dimethylaminohexadecyl methacrylate (DMAHDM) and amorphous calcium phosphate nanoparticles (NACP) on the physical and antibacterial properties of an experimental resin infiltrant (ERI).

Methodology: The following groups were established: ERI (75/25 wt.% TEGDMA/BISEMA), ERI + 2.5% DMAHDM (2.5DM), ERI + 5% DMAHDM (5DM), ERI + 2% NACP (NACP), ERI + 2.5% DMAHDM + 2% NACP (2.5DM_NACP), ERI + 5% DMAHDM + 2% NACP (5DM_NACP), and Icon® (IC), a commercial resin infiltrant. Degree of conversion (DC; n=4), sorption and solubility (SO/SOL; n=8), and contact angle (CA; n=10) tests were conducted. Biofilm biomass (BB; n=6) and bacterial metabolism (BM; n=8) were evaluated after Streptococcus mutans (UA159) cultivation for 48 h on material samples. Data were evaluated by one-way ANOVA and Tukey or Games-Howell post hoc tests (α=0.05).

Results: IC exhibited the highest DC, with no difference from 2.5DM and 5DM. IC showed the lowest CA. IC had the lowest SO, followed by ERI, which had the lowest SOL, with no difference from IC. 5DM_NACP showed the lowest biofilm biomass, similar to 2.5DM and 5DM. Resin infiltrants containing DMAHDM showed reduced bacterial metabolism.

Conclusions: DMAHDM, with or without NACP, demonstrated significant antibacterial activity, while NACP impaired DC. Both DMAHDM and NACP increased the contact angle, sorption, and solubility of the resin infiltrant, which may affect the material's clinical performance.

Objective: Periodontal dental ligament mesenchymal stem cells (PDLMSCs) play a major role in periodontal tissue regeneration by the neoformation of root cementum and alveolar bone. These cells are highly heterogeneous, and many present low potential to renovate the hard tissue damaged by periodontal disease. A previous study found that the low osteoblast/cementoblast (O/C) differentiation potential of PDLMSCs is related to high asporin (ASPN) expression, which was identified as a negative regulator of PDL cells differentiation and mineralization, suppressing BMP-2-induced O/C differentiation. This study aimed to investigate whether 1,25(OH)2D3 treatment could stimulate the O/C differentiation of periodontal ligament mesenchymal progenitor cells characterized as low osteoblast potential (LOP), by asporin and bone morphogenetic protein-2 alteration.

Methodology: Three LOP cell populations were cultured in standard medium (CONTROL), osteogenic medium (OM), and osteogenic medium associated with 1 nM of 1,25(OH)2D3 (OM + VD). The following assays were performed: 1) MTT to evaluate metabolic activity; 2) gene expression for asporin (ASPN), bone morphogenetic protein-2 (BMP-2), runt-related transcription factor 2 (RUNX2), alkaline phosphatase (ALP), osteocalcin (OCN), and vitamin D receptor (VDR) using qRT-PCR; 3) BMP-2 extracellular expression; and 4) quantification of mineralized nodule deposition by Alizarin Red Staining. Data were subjected to two-way ANOVA and Tukey's test (P<0.05).

Results: The results showed that the 1,25(OH)2D3 treatment did not affect the cell viability, as demonstrated by metabolic activity increase over the 10 days in culture. After 14 days of 1,25(OH)2D3 treatment, the mRNA levels for ASPN and VDR decreased (P<0.05), while BMP-2 transcripts and extracellular expression increased (P<0.05). In parallel, RUNX2, ALP, and OCN gene expression was upregulated by 1,25(OH)2D3 treatment, resulting in an increase of mineral nodule deposition in vitro (P<0.05).

Conclusions: These data show that 1,25(OH)2D3 improves osteoblast/cementoblast differentiation of low osteoblast potential accompanied by alterations in ASPN and BMP-2 expression.

Objective: Cleft lip and palate are the most common congenital malformations in the craniofacial region, occurring at a rate of 1:700 births in Brazil. These conditions lead to functional impacts on patients, such as changes in breathing, teeth, speech, chewing, swallowing and sucking. Treatment begins with primary surgeries, including lip and palate repair, which aim to reconstruct the soft tissues. Secondary alveolar bone grafting (SABG) reconstructs the bone defect in the cleft region, with the main goal of supplying bone tissue to the cleft region and restore the continuity of the alveolar process. To measure the changes in cross-sectional areas (CSAs) and nasal volume in patients and their impact on the nasal cavity (NC) in the two-month postoperative period (PO2M).

Methodology: This study included 15 patients with complete unilateral cleft lip and palate (U/CLP) indicated for alveolar bone grafting (ABG). Cone beam computed tomography scans obtained prior to SABG and at PO2M were compared. Nasal volumes and CSAs were measured by marking the masks delimiting the nasal cavity on CT scans using Mimics™ software.

Results: NC volumes (total, right and left sides) were statistically lower at PO2M in patients with left-sided UCLP. In right-sided UCLP, these volumes were only significant for the total NC and left NC. The CSAs of the internal nasal valve in both groups showed significantly lower values compared to the preoperative period (p≤0.05).

Conclusion: In the short term, alveolar bone graft surgery reduces the volume of nasal cavities and the cross-sectional areas of the right and left internal nasal valve as a whole, not only the cleft area where the graft material was placed.

Objective: Although autogenous grafting is accepted as the gold standard in intraoral grafting, xenogenous grafts are frequently used in sinus lift surgeries due to their osteoinductive and osteoconductive properties. This study aimed to investigate the efficacy of fish spine-derived xenogenic grafts in sinus augmentation surgery.

Material and methods: In this study, a fish spine-derived xenogenic graft was produced for comparison with autogenous graft and bovine derived xenogenic grafts. Twenty-one New Zealand rabbits were used. Autogenous grafts (AG- Group 1), as well as bovine-derived (bHAP - Group 2) and fish spine-derived (fHAP - Group 3) xenogenic grafts were placed in the right and left sinuses of rabbits. The animals were sacrificed at the 4th and 8th weeks. New bone formation (NBF) was evaluated through histological examination, while bone volume (BV), new bone surface/bone volume (BS-BV), new bone surface/tissue volume (BS-TV), and trabecular separation (Tb-Sp) were assessed via Micro-CT. Statistical significance was considered at p<0.05.

Results: Histological examination revealed a significant difference in NBF between AG-bHAP (p<0.001), as well as between fHAP-bHAP (p<0.001) in the fourth-week group. No significant difference was found in the eighth-week group (p=0.130). In the eighth-week group, a statistically significant difference was found between fHAP and bHAP in terms of BV. (p=0.007).

Conclusion: Although both graft materials used in this study showed positive effects on bone regeneration, fHAP and AG presented similar effects on bone regeneration and were superior to bHAP.

Objective: Diabetes mellitus (DM) delays wound healing, including those following tooth extractions. Curcumin (CCM) can promote soft tissue and bone healing. The present study investigates the healing effects of CCM on tooth extraction sockets in diabetic rats.

Methodology: Ninety-six male Wistar rats were divided into the following four groups: Control+Corn Oil (CO), Control+CCM, DM+CO, and DM+CCM. Each group was subdivided into 7-, 14-, and 28-day time point subgroups comprising eight rats. All animals had their maxillary first molars extracted. CCM-treated rats received 100 mg/kg of CCM orally for 7, 14, and 28 days. The lesion area was evaluated using macroscopic analyses, whereas socket healing was assessed by hematoxylin and eosin staining. Keratinocyte growth factor (KGF), Runt-related transcription factor 2 (Runx2), and collagen type I (COL1) expression levels were obtained using quantitative polymerase chain reaction (qPCR). Bone healing was analyzed by means of microcomputed tomography (μCT).

Results: After 7 days, the groups showed no significant differences in lesion area and by day 14, no lesions were present. CCM treatment increased KGF mRNA expression in diabetic rats; however, diabetic rats showed delayed bone healing unrelated to CCM. CCM treatment resulted in increased Runx2 mRNA expression only in control rats, whereas COL1 mRNA expression remained unaffected by CCM.

Conclusion: CCM shows potential as a soft tissue healing enhancer in diabetic rats and could serve as an additional treatment to promote soft tissue repair in diabetic individuals. Although CCM did not impact alveolar bone healing, it may enhance bone healing in other skeleton regions.

Background: the escalating influx of patients with temporomandibular disorders and the challenges associated with accurate diagnosis by non-specialized dental practitioners underscore the integration of artificial intelligence into the diagnostic process of temporomandibular disorders (TMD) as a potential solution to mitigate diagnostic disparities associated with this condition.

Objectives: In this study, we evaluated a machine-learning model for classifying TMDs based on the International Classification of Orofacial Pain, using structured data.

Methodology: Model construction was performed by the exploration of a dataset comprising patient records from the repository of the Multidisciplinary Orofacial Pain Center (CEMDOR) affiliated with the Federal University of Santa Catarina. Diagnoses of TMD were categorized following the principles established by the International Classification of Orofacial Pain (ICOP-1). Two independent experiments were conducted using the decision tree technique to classify muscular or articular conditions. Both experiments uniformly adopted identical metrics to assess the developed model's performance and efficacy.

Results: The classification model for joint pain showed a relevant potential for general practitioners, presenting 84% accuracy and f1-score of 0.85. Thus, myofascial pain was classified with 78% accuracy and an f1-score of 0.76. Both models used from 2 to 5 clinical variables to classify orofacial pain.

Conclusion: The use of decision tree-based machine learning holds significant support potential for TMD classification.

Background and objective: Periodontitis is an inflammatory disease typically characterized by the destruction of periodontal tissues and complicated etiology. DNA methyltransferase 3A (DNMT3A) has been implicated in possessing pro-inflammatory properties. This study sought to explore the role of DNMT3A in periodontitis and its relevant mechanism.

Methodology: Lipopolysaccharide (LPS) was used to induce inflammation in human periodontal ligament stem cells (hPDLSCs). DNMT3A and KLF5 expressions were detected using RT-qPCR and western blot. The levels of inflammatory cytokines and inflammation-related proteins were detected using ELISA and western blot. NF-κB p65 expression was detected using immunofluorescence (IF) assay, while osteogenic differentiation was assessed using ALP assay and ARS staining. Western blot was used to measure the protein contents associated with osteogenic differentiation. DNMT3A activity was detected using luciferase report assay and chromatin immunoprecipitation (ChIP) was used to verify the interaction between KLF5 and DNMT3A.

Results: DNMT3A expression increased in LPS-induced hPDLSCs. Silencing DNMT3A suppressed the LPS-induced inflammation in hPDLSCs, while promoting osteogenic differentiation. It was also found that transcriptional factor KLF5 could bind to DNMT3A promoters and regulate DNMT3A expression. Rescue experiments showed that KLF5 interference partially counteracted the inhibitory impacts of DNMT3A deficiency on inflammation and the promotive effects on osteogenic differentiation in LPS-induced hPDLSCs.

Conclusion: DNMT3A, when transcriptionally downregulated by KLF5, could alleviate LPS-challenged inflammatory responses and facilitate osteogenic differentiation in hPDLSCs.