Biome-microbiome interactions in peri-implantitis: A pilot investigation.

BACKGROUND: Dental implants replace missing teeth in at least 100 million people, yet over one million implants fail every year due to peri-implantitis, a bacterially induced inflammatory disease. Our ability to treat peri-implantitis is hampered by a paucity of information on host-microbiome interactions that underlie the disease. Here, we present the first open-ended characterization of transcriptional events at the mucosal-microbial interface in the peri-implant crevice. METHODS: We simultaneously sequenced microbial and human mRNA from five pairs of healthy and diseased implants from the same patient and used graph theoretics to examine correlations between microbial and host gene expression in the peri-implant crevice. RESULTS: We identified a transcriptionally active peri-implant microbiome surrounding healthy implants. Microbial genes encoding phenylalanine, tyrosine, and tryptophan biosynthesis, cysteine, methionine, arginine, proline, and histidine metabolism correlated to human genes encoding cell development, metabolism, morphogenesis, adhesion, gap junctions, cell-cell signaling, and immunoinflammatory pathways, suggesting a role for commensals in protecting epithelial integrity. In disease, we found 4- to 200-fold upregulation in microbial genes encoding biofilm thickness, heme transport and utilization, and Gram-negative cell membrane synthesis. These genes correlated with mucosal zinc finger proteins, apoptosis, membrane transport, inflammation, and cell-cell communication. CONCLUSIONS: Within the limitations of a small sample size, our data suggest that microbial dysbiosis in the peri-implant sulcus might promote abandonment of host-bacterial transactions that dictate health and instead drive a move towards chronic programming of a non-healing wound.

Estrogen and extracellular matrix influence human gingival fibroblast proliferation and protein production.

BACKGROUND: A paucity of information exists concerning how estrogen affects cellular function in the gingiva of women. In this study, the behavior of human gingival fibroblasts was examined in the presence of a potent estrogen, estradiol. METHODS: Quiescent, premenopausal gingival fibroblasts were incubated in the presence and absence of estradiol (1 nM) and/or raloxifene (100 nM). Cell number was determined and cell cycle analyzed using a flow cytometer. Collagen and non-collagen production in cell cultures grown on various extracellular matrices were determined using a radioactive microassay which measures collagenase-digestible and collagenase-resistant radiolabeled proteins. To ascertain if the gingiva contained specific estrogen-sensitive cell populations, a fluorescence-activated cell sorter was used to detect, sort, and enrich fibroblast populations responsive to estrogen. RESULTS: Cellular proliferation and the number of cells entering the S-phase of the cell cycle were significantly increased in mass cultures of fibroblasts stimulated by estradiol. Raloxifene did not antagonize the action of estradiol on cell proliferation. In regard to protein production, estradiol significantly reduced collagen production on plastic and collagen IV matrices; whereas non-collagen protein production on plastic and collagen I matrices was significantly reduced. Cell sorting of mass fibroblast populations revealed that, on average, 45% of the cells from the resident population selectively accumulated the estrogen probe. These sorted and estrogen-sensitive enriched cell populations proliferated in the presence of 1 nM estradiol, whereas the sorted, estrogen-deficient enriched fibroblast populations did not proliferate when incubated with 1 nM estradiol. CONCLUSIONS: These data indicate that estradiol can induce cellular proliferation while depressing protein production in cultures of human, premenopausal gingival fibroblasts. This cellular proliferation appears to be the result of a specific population of cells within the parent culture that responds to physiologic concentrations of estradiol.

Intrapocket anesthesia for scaling and root planing in pain-sensitive patients.

BACKGROUND: In 2 previous multicenter studies evaluating the efficacy of a novel anesthetic gel (lidocaine 25 mg/g plus prilocaine 25 mg/g), there was a rather small, although statistically significant, overall difference between the active and placebo gels. There were, however, large center variations. At centers where the placebo-treated patients reported high pain scores, the difference between treatments was large, suggesting that the anesthetic gel is most effective in patients who experience the procedure as painful. The present multicenter, double-blind, randomized study evaluated the anesthetic effect of this gel in pain-sensitive patients by using a visual analog scale (VAS) and a verbal rating scale (VRS). METHODS: One hundred thirteen (113) patients with moderate to severe periodontitis were screened for pain sensitivity upon probing. Eighty-five reported VAS > or = 30 mm on probing and were included in the treatment phase (43 anesthetic and 42 placebo gel). The periodontal pockets of one quadrant in each patient were treated with gel for 30 to 45 seconds, followed by scaling and/or root planing. RESULTS: The results were similar between centers. The median overall VAS pain score was 11 mm in the anesthetic group and 27 mm in the placebo group. The Hodges-Lehmann point estimate of the treatment difference was 10 mm (P = 0.004). No pain or only mild pain was reported by 70% in the anesthetic group and by 48% in the placebo group (P = 0.003). Two patients in the anesthetic group and 7 patients in the placebo group required rescue anesthesia. CONCLUSIONS: This study confirms the favorable anesthetic efficacy of active gel over placebo in selected pain-sensitive patients. It suggests that the gel may be a valuable alternative to conventional injection anesthesia.

Geriatric pharmacology.

With the dramatic demographic change that has resulted in the "graying of the population" has come a compelling interest in the health and health concerns of older adults. The increasing incidence and prevalence of systemic diseases, especially chronic diseases, among older adults, and the concomitant increase in medication use, have provided impetus for the subspecialty of geriatric pharmacology. This article reviews the physiologic changes, nonphysiologic aspects, and pharmacologic changes associated with aging and their implications for dental practice.

Squamous odontogenic tumor: diagnosis and management.

The squamous odontogenic tumor (SOT) is a rare, benign, locally infiltrative neoplasm of the jaws that appears to originate from the rests of Malassez. It has been confused with other pathologic entities such as ameloblastomas, carcinomas, and fibromas and clinically may resemble localized periodontal disease. The tumor is often asymptomatic, although it can present with symptoms of pain and tooth mobility. A characteristic radiographic appearance is that of a triangular-shaped or semi-circular lucency associated with the roots of erupted teeth. Histologically, the tumor is characterized by the formation of variably sized nests and cords of uniform, benign-appearing, squamous epithelium with occasional vacuolization and keratinization. Treatment of SOT by conservative surgical excision is normally curative with rare episodes of recurrence reported. Since the clinical presentation of SOT may mimic more common pathologic entities, this case report reinforces the need for careful histologic evaluation of all lesions found in the periodontium.