Oral Biology

Characterization of titanium surface coated with epidermal growth factor and its effect on human gingival fibroblasts Publication date: June 2019 Source: Archives of Oral Biology, Volume 102 Author(s): Taisa Nogueira Pansani, Fernanda Gonçalves Basso, Isabela dos Reis Souza, Josimeri Hebling, Carlos Alberto de Souza Costa Abstract Objectives Different strategies, such as modifications on the implant abutments surface have been proposed to accelerate and improve the formation of the biological seal (BS). The aim of this study was to characterize a titanium (Ti) surface impregnated with epidermal growth factor (EGF) and to assess its influence on the metabolism and adhesion of oral mucosal cells. Design Ti discs were coated with EGF (100 nM) conjugated with a fluorophore and analyzed by fluorescence microscopy. The surface roughness analysis (Ra) of the EGF-coated Ti was performed by confocal microscopy. The EGF released in the wet environment was determined at 0, 24, 48 and 72 h by fluorimetric quantification. For assessment of the biological effects of EGF-coated Ti, gingival fibroblasts were seeded (5 × 104 cells) onto the substrate coated or not with this growth factor. After 24 h, cell adhesion and viability were evaluated by ANOVA and Tukey tests, α = .05. Results Immediate release of EGF as well as its incorporation by fibroblasts within 1 h after cells were seeded was observed. EGF-coated Ti discs presented significantly enhance surface roughness. Increased cell viability was observed on the EGF-coated discs. Conclusion EGF applied to Ti discs stimulated the adhesion and metabolism of gingival fibroblasts and could be considered as an interesting alternative for improving the BS.

Periodontal condition of patients with Thalassemia Major: A systematic review and meta-analysis Publication date: June 2019 Source: Archives of Oral Biology, Volume 102 Author(s): Aliye Akcalı, Mehmet Selim Yıldız, Zeynep Akcalı, Olivier Huck, Anton Friedmann Abstract Objectives The aim of this systematic review was to evaluate the existing evidence on the association between Thalassemia major (TM) and periodontal condition. Materials & methods MEDLINE via OVID, EMBASE, and The Cochrane Database (including the Central Register of Controlled Trials (CENTER)), were searched up to September 2018 to identify observational studies eligible for systematic review and meta-analyses. Newcastle-Ottawa Scale (NOS) was used for quality assessment. Results The initial search resulted in 172 articles, and of these, 16 articles were included and a qualitative synthesis was carried out. Based on the quantitative data from 14 studies, significant differences were found in gingival index (GI) (p < 0.001), bleeding on probing (p = 0.02) as well as plaque index (PI) (p < 0.01) measures between TM and systemically healthy controls. Additional analyses (young vs. adult) for GI and PI revealed that such significant differences were only observed in adults, even though overall analysis showed no subgroup effect. The majority of the studies qualified as "intermediate quality". Conclusion Patients with TM had significantly higher gingival inflammation scores compared to controls. Therefore, routine comprehensive periodontal screening in TM is recommended in order to prevent occurrence of periodontal diseases and eventually reduce the complexity of the oral health care. Also, conduction of further well-designed observational studies is recommended to contribute to this topic.

MicroRNA-23a inhibits osteogenesis of periodontal mesenchymal stem cells by targeting bone morphogenetic protein signaling Publication date: June 2019 Source: Archives of Oral Biology, Volume 102 Author(s): Yuchen Zhang, Shiying Li, Shujing Yuan, Huifeng Zhang, Jingying Liu Abstract Objectives To investigate the role of microRNA-23a (miR-23a) in the osteogenesis of periodontal mesenchymal stem cells (PDLSCs) in periodontitis. Materials and methods Gingival crevicular fluid samples were collected from 21 control subjects and 29 patients with chronic periodontitis. MiR-23a was determined by quantitative real-time PCR. PDLSCs were transfected with miR-23a overexpressing lentiviruses. Subsequently, PDLSCs were induced with osteogenic differentiation media. Osteogenic differentiation of PDLSCs was assessed by alkaline phosphatase activity assay, Alizarin red staining, and qRT-PCT detection of osteogenic gene expression. Western blot was performed to detect the protein levels of the SMAD family member 1/5/9 (Smad1/5/9) and their phosphorylation level. TargetScan was used to predict the target gene of miR-23a. Cotransfections of bone morphogenetic protein receptor type 1B (BMPR1B) and miR-23a applied to explore the relationship between BMPR1B and miR-23a. Results MiR-23a was significantly increased in PDLSCs and gingival crevicular fluid of periodontitis patients. Patients with gingival crevicular fluid miR-23a levels above a threshold showed more clinical indicators of periodontitis. After periodontal therapy, miR-23a levels significantly decreased. Overexpression miR-23a inhibited osteogenesis of PDLSCs, which was evidenced by reduced Alizarin Red S and osteogenic gene expressions. In addition, miR-23a inhibited the phosphorylation of Smad1/5/9. TargetScan predicted that BMPR1B is a target gene of miR-23a. Overexpression of BMPR1B abolished the effects caused by overexpression of miR-23a. Conclusion Our study provides novel evidence that miR-23a acts as a negative regulator of osteogenesis in periodontitis patients'PDLSCs and that miR-23a may serve as a biomarker and potential target of periodontitis.

Acetaminophen reduces apical root resorption during orthodontic tooth movement in rats Publication date: June 2019 Source: Archives of Oral Biology, Volume 102 Author(s): Masato Kaku, Taeko Yamamoto, Yuka Yashima, Jin Izumino, Haruka Kagawa, Kazutaka Ikeda, Kotaro Tanimoto Abstract Objective The present study aimed to investigate the inhibitory effect of acetaminophen on apical root resorption during orthodontic tooth movement by controlling inflammation in the periodontal ligament and apical pulp tissue. Methods Human periodontal ligament and pulp cells were subjected to 10 kPa of cyclic tensile force (CTF) in a Flexcell Strain Unit for 48 h. Then, 10 and 100 μM acetaminophen were added to the culture medium, and the expression of interleukin (IL)-1B, receptor activator of nuclear factor kappa-B ligand (RANKL), tumor necrosis factor (TNF)α, and colony stimulating factor 1 (CSF1) were evaluated. In an animal experiment, the upper first molars of 7-week-old rats were moved mesially by applying 10 g of orthodontic force. After 30 days of force application, the effects of acetaminophen on apical root resorption were examined. Results In both the periodontal ligament and pulp cells, the expression levels of IL-1B, TNFα, RANKL, and CSF1 were significantly higher in the CTF-treated group than in the control group. However, the expression levels of these factors were decreased by acetaminophen administration. High expression of IL-1B, TNFα, RANKL, and CSF1 at the root apex were also detected immunohistochemically in rats after tooth movement, but were decreased by acetaminophen administration. In addition, the number of odontoclasts and the amount of apical root resorption were significantly decreased in the acetaminophen group. Importantly, no significant difference in tooth movement was observed between the acetaminophen and control groups. Conclusions These results suggest that acetaminophen can reduce severe root resorption in the apex area without disturbing orthodontic tooth movement.

Tea polyphenols: The application in oral microorganism infectious diseases control Publication date: June 2019 Source: Archives of Oral Biology, Volume 102 Author(s): Yuan Li, Xiaoge Jiang, Jianqi Hao, Yifei Zhang, Ruijie Huang Abstract One of the most popular drinks worldwide, tea is rich in polyphenols and is beneficial to our health because it contributes to the prevention of many diseases. In the human oral cavity, there are more than 750 different species of bacteria living together within dental plaque. Some of the bacteria are pathogens that contribute to the development of oral diseases such as dental caries, periodontitis, pulpitis, mucosal disease, or halitosis through their virulence factors and their metabolites. Until now, many studies have reported that tea polyphenols (TPs) have evident inhibitory effects on some oral pathogenic microorganisms by suppressing pivotal steps of their pathogenic processes. The aim of this review is to summarize the effectiveness and mechanisms of TPs in inhibiting microorganisms, so as to provide new ideas for the prevention and treatment of oral diseases, and to contribute to the global dental public health.

Influence of adjuvant therapy with green tea extract in the treatment of experimental periodontitis Publication date: June 2019 Source: Archives of Oral Biology, Volume 102 Author(s): Juliano Milanezi de Almeida, Bianca Mayara Marques, Vivian Cristina Noronha Novaes, Fred Lucas Pinto de Oliveira, Henrique Rinaldi Matheus, Luiz Guilherme Fiorin, Edilson Ervolino Abstract Aim This study evaluated the effects of topical green tea extract solution (GTE) as adjuvant therapy to mechanical debridement for the treatment of experimental periodontitis (EP). Material and methods We used 120 male rats (Rattus norvegicus albinus – Wistar), divided into the following four groups: NEP (sham) (n = 30): no experimental periodontitis (NEP), only simulation of EP by installation and removal of a ligature; EP (n = 30): EP induction by ligature; SRP (n = 30): EP, scaling and root planing (SRP), and irrigation with physiological saline solution; SRP/GT (n = 30): EP, SRP, and irrigation with GTE. Histologic analysis and immunohistochemistry were performed for detection of interleukin (IL)1ß, tumor necrosis factor-alpha (TNF-α), IL-10, and anti-tartrate resistant acid phosphatase (TRAP) in the furcation area. The percentage of bone in the furcation (PBF) was considered the primary variable and evaluated at 14, 22, and 37 days. The data from the histological analysis and the IL- 1B, TNF- A, and IL-10 were submitted to a Kruskal-Wallis variance test and Dunn's posttest (p ≤ 0.05). The histometric data and TRAP were submitted to analysis of variance (ANOVA) and Tukey's posttest (p ≤ 0.05). Results The SRP/GT group showed lower inflammatory process, lower immunolabeling pattern of IL-1ß and TNF-α, and greater immunolabeling pattern of IL-10 compared with the EP and SRP groups at 22 days. Fewer TRAP-positive multinucleated osteoclasts were observed in all periods in the SRP/GT group (5.22 ± 0.65; 7.33 ± 0.80; 8.55 ± 1.15) compared with the SRP group (30.67 ± 8.55; 13.22 ± 0.77; 13.87 ± 0.77). Higher PBF was observed in all periods in the SRP/GT group (74.65 ± 7.14; 76.61 ± 5.36; 79.24 ± 3.75) compared with the SRP group (61.60 ± 9.48; 54.84 ± 9.06; 53.25 ± 9.66). Conclusion GTE adjuvant to SRP reduced inflammation, osteoclastic activity, and alveolar bone loss in EP.

Autophagy in periodontal disease: Evidence from a literature review Publication date: June 2019 Source: Archives of Oral Biology, Volume 102 Author(s): Alejandro I. Lorenzo-Pouso, Pablo Castelo-Baz, Mario Pérez-Sayáns, Jason Lim, Yago Leira Abstract Objective To summarize evidence and data relating to the implications of autophagy in periodontal disease (PD) and to describe potential nutraceuticals or pharmaceuticals that could modulate this cell death subtype. Design Literature searches of various electronic databases (Medline via PubMed, SCOPUS, Web of Science, and EMBASE) using appropriate keywords (e.g., periodontal disease, periodontitis, alveolar bone loss, periodontal infection, tooth loss, autophagy, programmed cell death, and type 2 cell death) were performed. Then, a comprehensive literature review of the current understanding of this link was elaborated. Results Autophagy plays a pivotal role in PD, and its regulation seems to be an interesting avenue for future periodontal research, according to several in vivo and in vitro reports. Conclusion Today's research has ascertained the role of autophagy in PD, especially its role in the host's defence against periodontal disease drivers. A bulk of the research recognised several pharmaceuticals and nutraceuticals that could potentially modulate this kind of cell death and serve as useful therapies. However, further research is warranted to reach a clinical translation, which could help in the discovery of novel host modulation therapies for PD.

The pH-dependent effect of cationic and non-ionic delmopinol on planktonic and biofilm bacteria Publication date: June 2019 Source: Archives of Oral Biology, Volume 102 Author(s): Torgny Sjödin Abstract Objectives The primary purpose was to evaluate the antimicrobial effects of cationic and non-ionic delmopinol on planktonic and biofilm bacteria. Methods Determination of the minimum inhibitory concentrations on planktonic and biofilm bacteria was performed below and above the pKa-value of delmopinol. Test bacteria were Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli and Pseudomonas aeruginosa. Comparisons were made with three antimicrobial agents and "quaternary" delmopinol. Synergy testing of delmopinol was determined with serial dilutions of delmopinol with the other compounds in a checkerboard fashion, and the fractional inhibitory concentration index (FIC) was calculated. Results Delmopinol showed minor differences between its MIC- and MBEC-values for all bacterial strains (MBEC/MIC-ratios of 1–2). For the other compounds the difference between their MIC- and MBEC-values were higher and varied considerably between the bacteria. The MIC- and MBEC-concentrations were lower at pH where the non-ionic form of delmopinol dominates. "Quaternary" delmopinol showed the same MIC-concentrations as delmopinol, but needed much higher concentrations to kill biofilm bacteria. Synergy testing showed FIC-indices of 0.5–1. Conclusions The biofilm penetration of non-ionic delmopinol is better than for cationic delmopinol. Likewise, the cationic test reference samples exerted limited biofilm penetration. The increased efficacy of non-ionic delmopinol is probably due to reduced binding to negative groups in the extracellular matrix of polymeric substances surrounding biofilm bacteria. It is also proposed that the non-ionised form of delmopinol deposits on the biofilm surface. Higher amounts of delmopinol than expected will therefore accumulate. Combinations of delmopinol with other compounds suggests an additive antimicrobial effect.

Corrigendum to "Efficacy of different strategies to treat root dentin eroded by liquid or gaseous hydrochloric acid associated with brushing abrasion" [Arch. Oral Biol. Vol. 89 (2018), Pages 65–69] Publication date: June 2019 Source: Archives of Oral Biology, Volume 102 Author(s): Juliana Jendiroba Faraoni, Carmen Victoria Torres Toro, Laís Lopes Machado de Matos, Regina Guenka Palma-Dibb

Combination of estrogen deficiency and excessive mechanical stress aggravates temporomandibular joint osteoarthritis in vivo Publication date: June 2019 Source: Archives of Oral Biology, Volume 102 Author(s): Yuyun Wu, Chiho Kadota-Watanabe, Takuya Ogawa, Keiji Moriyama Abstract Objective It has been suggested that degenerative conditions of the temporomandibular joint (TMJ), such as osteoarthritis (OA) and progressive condylar resorption, are caused by multiple etiological factors, such as hormonal imbalance and excessive mechanical stress. However, it is unclear whether these factors interrelate in the degenerative process of the condyle. The aim of this study was to observe the effects of combined hormonal imbalance and excessive mechanical stress on the condyle using a mouse model. Materials and methods Ovariectomy (OVX) was performed in 8-week-old female mice. Three weeks after OVX, a build-up resin was bonded to the right maxillary molars to create imbalanced occlusion (increased occlusal vertical dimension, iOVD). Mice were divided into four groups: control, OVX, iOVD, and OVX + iOVD. Results Histomorphometric analysis showed the lowest cartilage thickness and the highest TMJ-OA score in the OVX + iOVD group. Bone structural analysis showed significantly lower subchondral bone mass in all experimental groups. Additionally, the OVX + iOVD group showed up-regulated osteoclastic activity and increased apoptosis in the condyle. Gene expression analysis showed significantly elevated expression of pre-inflammatory cytokines in the OVX + iOVD group. These data showed that the OVX + iOVD group exhibited the most severe inflammatory TMJ-OA. Upregulation of ERα and activation of the ERK pathway was observed in the OVX + iOVD group. Conclusions Additive effects of estrogen deficiency and excessive mechanical stress on the condyle exacerbate TMJ-OA. Furthermore, estrogen deficiency and excessive mechanical stress combined may exacerbate TMJ-OA though activation of the ERK pathway.