Soft tissue adhesion and sealing around dental and maxillofacial implants, related prosthetic components, and crowns are a clinical imperative to prevent adverse outcomes of periodontitis and periimplantitis. Zirconia is often used to fabricate implant components and crowns. Here, we hypothesized that UV treatment of zirconia would induce unique behaviors in fibroblasts that favor the establishment of a soft tissue seal. Human oral fibroblasts were cultured on zirconia specimens to confluency before placing a second zirconia specimen (either untreated or treated with one minute of 172 nm vacuum UV (VUV) light) next to the first specimen separated by a gap of 150 µm. After seven days of culture, fibroblasts only transmigrated onto VUV-treated zirconia, forming a 2.36 mm volume zone and 5.30 mm leading edge. Cells migrating on VUV-treated zirconia were enlarged, with robust formation of multidirectional cytoplastic projections, even on day seven. Fibroblasts were also cultured on horizontally placed and 45° and 60° tilted zirconia specimens, with the latter configurations compromising initial attachment and proliferation. However, VUV treatment of zirconia mitigated the negative impact of tilting, with higher tilt angles increasing the difference in cellular behavior between control and VUV-treated specimens. Fibroblast size, perimeter, and diameter on day seven were greater than on day one exclusively on VUV-treated zirconia. VUV treatment reduced surface elemental carbon and induced superhydrophilicity, confirming the removal of the hydrocarbon pellicle. Similar effects of VUV treatment were observed on glazed zirconia specimens with silica surfaces. One-minute VUV photofunctionalization of zirconia and silica therefore promotes human oral fibroblast attachment and proliferation, especially under challenging culture conditions, and induces specimen-to-specimen transmigration and sustainable photofunctionalization for at least seven days.

Oral potentially malignant disorders are associated with the development of oral squamous cell carcinoma (OSCC). Most OSCCs are diagnosed via histopathology as oral epithelial dysplasia (OED), but the histologic diagnostic criteria remain non-uniform. Accordingly, the establishment of a diagnostic marker to assist in diagnosis could contribute towards cancer prevention. Melanoma inhibitory activity (MIA) and MIA2 are involved in tumor growth, invasion, and lymph node metastasis in various malignancies. The purpose of this study was to clarify the usefulness of MIA and MIA2 as diagnostic markers of oral mucosal lesions. The expression of MIA and MIA2 was analyzed immunohistochemically in 100 specimens (10 specimens with normal oral mucosa (NOM) and 30 specimens each with low-grade epithelial dysplasia (LED), high-grade epithelial dysplasia (HED), and OSCC). Immunohistochemical results were evaluated based on the Allred scoring system. Cytoplasmic expression of MIA and MIA2 increased in the order of LED, HED, and OSCC. All NOM specimens were negative for cytoplasmic expression. Significant differences were observed between the groups (NOM vs. HED, p < 0.05, NOM vs. OSCC, p < 0.001). These results demonstrate that MIA and MIA2 are expressed in the oral mucosa within early neoplastic lesions and suggest that MIA and MIA2 are useful novel immunohistochemical markers for discriminating between normal tissue and OED.

Background/Objective: Glucocorticoids (GC) have anti-inflammatory effects, but long-term use can suppress bone formation and cause osteoporosis. The impact of inflammatory environments, such as periodontitis, on alveolar bone metabolism remains insufficiently understood. Methods: We used wild-type (C57BL/6J, n = 47) mice to compare glucocorticoid (GC) effects with and without sustained-release GC pellets. Mice were divided into GC-administered (2 weeks: n = 8; 4 weeks: n = 8; 8 weeks: n = 7) and non-GC-administered groups (2 weeks: n = 8; 4 weeks: n = 8; 8 weeks: n = 8). A ligature wire was placed around the left first molar of all mice to induce periodontal disease, while the right first molar served as a control. Femur and alveolar bone changes were assessed at 2, 4, and 8 weeks using μCT, HE staining, tartrate-resistant acid phosphatase (TRAP) staining, and immunohistochemistry (TNF-α). Anonymized evaluators performed histological analyses, and statistical analyses. One-way ANOVA with the Tukey post hoc test and t tests. Results: GC administration significantly reduced femoral bone mass at 2, 4, and 8 weeks. In mice without ligature, GC administration did not significantly affect alveolar bone mass or osteoblast number at 2 or 4 weeks, but a reduction was noted at 8 weeks post-treatment. No significant differences in osteoclast numbers or TNF-α levels were observed after GC administration. In a periodontal disease mouse model, GC administration led to greater bone loss, fewer osteoblasts, and increased osteoclasts and TNF-α levels. Conclusions: GC use in periodontal disease risks abnormal bone metabolism and progressive alveolar bone resorption.

ReveromycinA (RMA) was developed and is a unique agent for inhibiting osteoclast activity. In a previous study, we experimentally induced periodontal disease in a high-turnover osteoporosis osteoprotegerin-knockout mice (OPG KO) model and found that intraperitoneal administration of RMA inhibited alveolar bone resorption. We prepared a novel RMA-containing ointment for topical non-invasive administration in the oral cavity, in preparation for possible future clinical application. And we investigated whether this ointment can inhibit alveolar bone resorption in an experimental mouse model of periodontal disease. We examined wild-type (WT) and OPG KO mice ligated with wire around contact points on the left first and second molars to cause food impaction and induce experimental periodontal disease. RMA was administered three times a day. Using micro-computed tomography, we measured the volume of alveolar bone loss and also performed histological analysis. Our findings showed that localized administration of RMA containing ointment resulted in suppressed alveolar bone resorption, reduced osteoclast count, and lower immunostaining scores of inflammation sites compared with controls in both OPG KO and WT mice. Localized application of the specific osteoclast suppressor RMA in ointment form in the oral cavity could be a novel treatment for periodontitis that inhibits alveolar bone resorption locally.

Background/Objectives: Oral squamous cell carcinoma (OSCC) often presents at an advanced stage; therefore, the early detection of precursor lesions is crucial. However, the risk assessment of precursor lesions such as oral epithelial dysplasia (OED) remains challenging because of the subjectivity of histopathological grading. We aimed to identify molecular markers that enhance the diagnostic accuracy and prognostic stratification of OSCC and explore the differences in the molecular characterization of OED and OSCC using a few selected markers. Methods: A two-step diagnostic workflow was applied: (1) FISH evaluation of EGFR amplification and CDKN2A deletion to distinguish OED from OSCC and identify EGFR-dependent tumors, and (2) HRAS immunohistochemistry performed exclusively in EGFR-negative OSCCs to stratify EGFR-independent cases. Fluorescence in situ hybridization (FISH) was used to assess seven EGFR/cell cycle-related genes (CCND1, CDKN2A, EGFR, PIK3CA, PTEN, TP53, and 1p36 locus) in 117 formalin-fixed paraffin-embedded samples (66 OED and 51 OSCC) and 10 normal mucosa samples. HRAS expression was evaluated using immunohistochemistry (IHC) in 36 EGFR amplification-negative OSCCs samples. Results:EGFR amplification was frequent in OSCC, whereas CDKN2A deletion was common in OED. The EGFR-amplified/ CDKN2A-intact profile showed high specificity for OSCC and improved diagnostic performance (area under the curve = 0.77) when combined with the Ki-67 labeling index. It also predicted poor disease-free survival (hazard ratio [HR] = 5.08, p = 0.016) and overall survival (HR = 6.10, p = 0.047). Among EGFR-negative OSCCs, HRAS overexpression was associated with advanced-stage disease and a poor prognosis (HR = 6.15, p = 0.043). Conclusions:EGFR amplification was frequent in OSCC, and CDKN2A deletion was prevalent in OED, supporting their use as molecular markers for differential diagnoses. FISH for EGFR/CDKN2A and HRAS IHC can stratify OSCC by diagnosis and prognosis, enabling practical molecular subclassification, including EGFR-negative cases.