University of Missouri–Kansas City School of Dentistry

BACKGROUND:Perigraftitis is a recently introduced concept describing biologic complications specifically associated with implants placed in grafted bone. It is characterized by inflammation resulting from bacterial colonization of grafted bone and/or residual graft particulates. Reported cases have been managed by removal of the implant, grafted bone, and surrounding inflammatory tissue, and therefore have not definitively established perigraftitis as an independent disease entity. This report describes a histologically confirmed case of perigraftitis treated successfully without implant removal, supporting its recognition as a distinct pathologic condition. METHODS:A 63-year-old healthy, nonsmoking Asian male presented with discomfort, and a foul taste around implant #31, placed in a site previously grafted with deproteinized bovine bone mineral. Examination revealed infection and bone loss that centered on the grafted bone, and the site was diagnosed with perigraftitis. The implant crown was removed, and surgical access was obtained using a laser. Three hard tissue specimens were removed and submitted for histology, revealing numerous graft particulates surrounded by mature necrotic host bone with bacterial aggregates within intertrabecular spaces of all three specimens. The site was thoroughly debrided and allowed to heal without the use of any biomaterials. RESULTS:Three weeks post-treatment, symptoms had resolved. At 13.5 months post-treatment, crestal bone regeneration up to the implant collar was observed. Vertical implant soft tissue augmentation with a subperiosteal circumferential connective tissue graft was then performed, and the implant crown was reseated following soft tissue healing. CONCLUSIONS:The histologic findings and clinical outcome of this case support the recognition of perigraftitis as an independent disease entity. Further controlled studies are warranted to elucidate the etiopathogenesis, risk factors, and prevalence of perigraftitis, and to optimize its prevention and treatment. KEY POINTS:Perigraftitis may be considered an independent disease entity, distinct from peri-implant mucositis and peri-implantitis. Perigraftitis is an inflammatory response induced by bacterial colonization of grafted bone and/or residual graft particulates, with the implant fixture and its transmucosal components likely providing the pathway for oral bacteria to access and infect the grafted bone. Perigraftitis may be successfully resolved through the removal of the infected grafted bone and associated inflammatory tissue without the need for implant removal. PLAIN LANGUAGE SUMMARY:A patient had discomfort, foul taste, and bone loss around an implant on the lower right jaw that had been placed into grafted bone. The site was diagnosed with perigraftitis, defined as inflammation resulting from infection of the grafted bone. The implant crown was removed, and a laser was used to obtain surgical access. Three hard tissue masses were removed and submitted for biopsy. The site was thoroughly cleaned and allowed to heal naturally. After 3 weeks, the patient reported discomfort and foul taste had resolved. Thirteen and a half months after treatment, bone had regenerated around the implant. Vertical implant soft tissue augmentation was then performed. The implant crown was reseated after soft tissue healing. The tissue biopsy confirmed infection of the grafted bone and the diagnosis of perigraftitis. The treatment outcome supports perigraftitis as an independent disease entity, distinct from peri-implant mucositis and peri-implantitis.

PURPOSE:This cross-sectional study aimed to evaluate dental students' experiences with an innovative online interactive platform that mimics real clinical diagnostic scenarios. The null hypothesis was that the interactive scenarios have no effect on students' perceived learning of endodontic diagnosis. METHODS:284 third-year dental students enrolled in preclinical endodontic courses at five US dental schools were exposed to three interactive online endodontic diagnostic scenarios. They then completed a validated questionnaire assessing usability, perceived learning effectiveness, and suggestions for improvements. The data was analyzed statistically with a significance level set at 5%. RESULTS:Participants recognized the difficult levels of each scenario, significantly perceived their level of knowledge increase after using the interactive learning tool (p < 0.05), and considered it was intuitive and would be beneficial in other courses. CONCLUSIONS:The online interactive endodontic diagnostic scenarios were perceived as successful in several aspects. After completing the modules, participants noted changes in scenario difficulty as their general subject knowledge increased. Participants indicated that the content provided an opportunity to think critically about information that applies to clinical experiences. Students further indicated that extending its use to other courses would be helpful.

This study investigated a combined strategy using collagen crosslinking and polymer-induced liquid precursors (PILP)-based remineralization to enhance collagen biostability and resistance to collagenase degradation in sound (SD), denatured (DD), and caries-affected dentin (CAD). Ultra-thin demineralized collagen films and acid-etched dentin beams with demineralized layers (DL) were treated with 1% cranberry-extract (CR) collagen crosslinker for 30 s, followed by PILP remineralization for 1-7 days. Biostability was assessed by collagenase-induced weight loss and hydroxyproline release; structural and remineralization changes were evaluated via electron microscopes. Both CR and PILP individually improved collagen biostability, with greater effects in SD than DD. CR crosslinking was more effective than PILP alone. Notably, the combined CR-PILP approach produced the greatest enhancement in biostability. Electron microscopes confirmed that this dual treatment preserved the DL from enzymatic digestion and dramatically accelerated mineral deposition in both SD and CAD. These findings support the potential of this synergistic strategy for improving dentin restoration durability.

OBJECTIVE:Perigraftitis is a biologic complication associated with dental implants placed in grafted bone, distinct from peri-implant mucositis and peri-implantitis. This report further characterizes its clinical, radiographic, and histopathologic features. CLINICAL CONSIDERATIONS:Three patients presented with discomfort around a single implant placed following tooth extraction and alveolar ridge preservation. Surgical access was obtained, and the implant fixture and surrounding defect were thoroughly debrided. Tissue fragments were submitted for histology, and sections from two previously reported cases were reexamined. Clinically, perigraftitis presented with signs of inflammation and radiographically as a radiolucent defect centered on the grafted bone rather than the implant fixture, containing radiopacities consistent with grafted bone and graft particulates. Histologically, grafted bone, composed of graft particulates surrounded by mature host bone, demonstrated microbial colonies and inflammatory cells. The hallmark histopathologic feature, irrespective of graft type, was microbial aggregates adherent to the surfaces and within the intertrabecular spaces of grafted bone, accompanied by inflammatory infiltrates. Sulfur granules and amoebae were novel observations. CONCLUSIONS:Perigraftitis arises from microbial colonization of grafted bone and is not restricted to a specific graft material. Implant recipient site grafting should be performed judiciously. Management requires complete removal of infected grafted bone and associated inflammatory tissue.

BackgroundOral epithelial dysplasia (OED) is a precancerous oral lesion with variable risk of progression to oral squamous cell carcinoma (OSCC). The molecular basis underlying this progression remains incompletely understood. To address this gap, this study applied spatial transcriptomics to characterize benign, OED and OSCC biopsies with a focus on the comparison between transforming and non-transforming OED.MethodsSpatial transcriptomic profiling was performed on 13 benign, 15 OED (8 transforming, 7 non-transforming), and 14 OSCC biopsies using the NanoString GeoMx Digital Spatial Profiler. Regions of interest were segmented into epithelial and immune-enriched compartments with morphological markers. Gene expression was measured using the GeoMx Cancer Transcriptome Atlas (~1, 800 genes) and differentially expressed genes (DEGs) were identified using linear mixed-effects modeling. Exploratory bioinformatic analyses were performed to provide biological context.ResultsComparison of OED with and without transformation identified a limited set of 11 epithelial DEGs, including genes associated with antigen presentation and interferon signaling (e.g., B2M, STAT1, and CD74), while no significant DEGs were detected in immune-enriched regions. Pathway analyses indicated enrichment of immune- and interferon-related processes. Given the modest sample size and targeted gene panel, these findings should be considered exploratory in nature.ConclusionsThis study provides spatially resolved, exploratory insights into molecular differences between OED lesions with distinct clinical outcomes. The results suggest altered epithelial-immune interactions in transforming lesions, though these findings require validation. Spatial transcriptomics may offer a useful framework for investigating early molecular changes in oral carcinogenesis.