Patients with chronic periodontitis present increased risk for osteoporosis: A population-based cohort study in Taiwan.

OBJECTIVES: Chronic periodontitis is a bone destructive inflammatory disease with an adverse impact on general health and suggested underlying factors in common with osteoporosis. A few studies have examined the possible relationship between chronic periodontitis and osteoporosis; however, the results remain inconclusive. This longitudinal follow-up study investigated the possible risk of patients with chronic periodontitis to present osteoporosis by using a population-based national health insurance data set in Taiwan. MATERIAL AND METHODS: A random sample consisting of 1 million individuals was collected from Taiwan's national health insurance data set. From the sample, a total of 29 463 patients with newly diagnosed periodontitis from 2002 to 2008 were recruited and compared with a matched cohort of 58 926 patients without periodontitis. All patients were tracked until an osteoporosis diagnosis, or death, until the end of 2011. Associated factors, such as gender, age and comorbidities were examined. Cox proportional-hazards regression was performed to examine the risk of osteoporosis for patients with or without periodontitis. RESULTS: Within the 6-year follow-up period, the incidence rates of osteoporosis in the periodontitis cohort and comparison group were 2.72 and 1.66 per 1000 person-years, respectively. Mild, moderate and severe periodontitis were found to have 1.56, 2.09 and 2.08 times the risk of osteoporosis respectively compared to patients without periodontitis. Log-rank analysis revealed that patients with periodontitis had significantly higher cumulative incidence rates of osteoporosis than the control group (P<.0001). CONCLUSION: This study found that patients with periodontitis had a higher risk of being diagnosed with osteoporosis.

Induction of apoptosis in oral epithelial cells by Candida albicans.

During infection, interactions between Candida albicans and oral epithelial cells result in oral epithelial cell death. This is clinically manifested by the development of oral mucosal ulcerations generally associated with discomfort. In vitro studies have shown that C. albicans induces early apoptotic alterations in oral epithelial cells; however, these studies have also shown that treatment of infected cells with caspase inhibitors does not prevent their death. The reasons for these contradictory results are unknown and it is still not clear if C. albicans stimulates oral epithelial signaling pathways that promote apoptotic cell death. Activation of specific death pathways in response to microbial organisms plays an essential role in modulating the pathogenesis of a variety of infectious diseases. The aim of this study was to (i) characterize C. albicans-induced apoptotic morphological alterations in oral epithelial cells, and (ii) investigate the activation of apoptotic signaling pathways and expression of apoptotic genes during infection. Candida albicans induced early apoptotic changes in over 50% of oral epithelial cells. However, only 15% of those showed mid-late apoptotic alterations. At the molecular level, C. albicans caused a loss of the mitochondrial transmembrane potential and translocation of mitochondrial cytochrome c. Caspase-3/9 activities increased only during the first hours of infection. Moreover, poly[ADP ribose] polymerase 1 was cleaved into apoptotic and necrotic-like fragments. Finally, five anti-apoptotic genes were significantly upregulated and two pro-apoptotic genes were downregulated during infection. Altogether, these findings indicate that epithelial apoptotic pathways are activated in response to C. albicans, but fail to progress and promote apoptotic cell death.

Implants in the pterygoid region: a systematic review of the literature.

This systematic review aimed to identify clinical studies on the short-term and long-term survival of implants placed in the pterygoid region. A structured literature search was conducted using PubMed, Scopus and Cochrane databases. Relevant studies were selected according to predetermined inclusion and exclusion criteria. Data from the final included studies could only be extracted for calculating interval survival rate (ISR) and cumulative survival rate (CSR) of implants for different time intervals. The initial database search yielded 693 titles. After filtering, 32 abstracts were selected culminating in 17 full text articles. Three additional articles were added through a hand search to obtain a total of 20 articles. Application of exclusion criteria led to elimination of 11 articles. Pooled data from the final 9 articles showed a first year ISR of 92%. The CSR over a 10 year period, largely due to data from one study was 91%. The minimum follow-up period reported in various studies was less than a year. There is insufficient data about failures that occurred beyond the first year interval, making it difficult to draw conclusions about long-term survival of these implants. More studies with longer follow-up periods involving adequate number of pterygoid implants are needed.

Transcriptional profiling of osseointegration in humans.

OBJECTIVE: To determine the temporal gene expression profile associated with the early healing events during osseointegration in a human model. MATERIAL AND METHODS: Nine solid screw-type cylindrical titanium implants, 4 mm long and 2.8 mm wide, with a chemically modified surface (SLActive) were surgically inserted in the retromolar area of nine human volunteers. The devices were removed using a trephine following 4, 7 and 14 days of healing. The tissue surrounding the implant was harvested, total RNA was extracted and microarray analysis was carried out to identify the differences in the transcriptome between days 4, 7 and 14. RESULTS: Gene ontology (GO) analysis of the temporal transcriptional changes was characteristic of a maturing, osteogenic process over the course of the study (4-14 days). At day 4, a gene expression profile associated with proliferation and immuno-inflammatory processes was predominant. However, by day 14, by far the most predominant mechanisms were associated with skeletogenesis, with the GO categories of skeletal system development, bone development and ossification being predominant, with the majority of changes occurring between days 7 and 14. Furthermore, the biological processes of angiogenesis and neurogenesis were also predominant by day 14. In terms of signal transduction, I-κB kinase/NF-κB cascade was predominant at day 4, whereas TGF-ß/BMP, Wnt and Notch signalling were all associated with the osteogenic process over the duration of the study. Furthermore, Ras and Rho protein signal transduction was regulated throughout the osseointegration process. CONCLUSION: The temporal transcriptional changes during osseointegration involve the expression of proliferation and immuno-inflammatory response associated genes during the early stages of osseointegration, which are ultimately replaced by genes associated with the biological processes of skeletogenesis, angiogenesis and neurogenesis. The early immuno-inflammatory changes appear to be regulated via the I-κB kinase/NF-κB cascade, whereas the later osteogenesis-related mechanisms are regulated by TGF-ß/BMP, Notch and Wnt signaling.

Gene expression profile of osseointegration of a hydrophilic compared with a hydrophobic microrough implant surface.

OBJECTIVES: To compare the gene expression profile of osseointegration associated with a moderately rough and a chemically modified hydrophilic moderately rough surface in a human model. MATERIAL AND METHODS: Eighteen solid screw-type cylindrical titanium implants, 4 mm long and 2.8 mm wide, with either a moderately rough (SLA) or a chemically modified moderately rough (SLActive) surface were surgically inserted in the retromolar area of nine human volunteers. The devices were removed using a trephine following 4, 7 and 14 days of healing. The tissue surrounding the implant was harvested, total RNA was extracted and microarray analysis was carried out to identify the differences in the transcriptome between the SLA and SLActive surfaces at days 4, 7 and 14. RESULTS: There were no functionally relevant gene ontology categories that were over-represented in the list of genes that were differentially expressed at day 4. However, by day 7, osteogenesis- and angiogenesis-associated gene expression were up-regulated on the SLActive surface. Osteogenesis and angiogenesis appeared to be regulated by BMP and VEGF signalling, respectively. By day 14, VEGF signalling remains up-regulated on the SLActive surface, while BMP signalling was up-regulated on the SLA surface in what appeared to be a delayed compensatory response. Furthermore, neurogenesis was a prominent biological process within the list of differentially expressed genes, and it was influenced by both surfaces. CONCLUSIONS: Compared with SLA, SLActive exerts a pro-osteogenic and pro-angiogenic influence on gene expression at day 7 following implant insertion, which may be responsible for the superior osseointegrative properties of this surface.

Association of the composite IL-1 genotype with peri-implantitis: a systematic review.

OBJECTIVE: Cytokine gene polymorphisms may modulate the host response to the bacterial challenge and influence susceptibility to peri-implantitis. OBJECTIVE: To systematically review the evidence of an association between the interleukin-1 (IL-1) composite genotype, i.e. presence of the allele 2 in the gene clusters IL-1A (-889) and in IL-1B (+3953), and peri-implantitis. MATERIAL AND METHODS: An electronic search in the National Library of Medicine-computerized bibliographic database MEDLINE and a manual search were performed. The search was conducted for longitudinal clinical trials comparing progression of peri-implantitis in IL-1 genotype positive (carrying allele 2) with IL-1 genotype negative (not carrying allele 2) subjects. Selection of publications, extraction of data and validity assessment were made independently by two reviewers. RESULTS: The search provided 44 titles of which two longitudinal publications were included. CONCLUSION: Based on the findings from this study, there is not enough evidence to support or refute an association between the IL-1 genotype status and peri-implantitis. Systematic genetic testing for the assessment of the risk of peri-implantitis cannot be recommended as a standard of care at this time.

The association of the composite IL-1 genotype with periodontitis progression and/or treatment outcomes: a systematic review.

BACKGROUND: Genetically transmitted traits such as cytokine gene polymorphisms may accentuate the host inflammatory response to the bacterial challenge and influence susceptibility to periodontitis. OBJECTIVE: To systematically review the evidence of an association between the interleukin-1 (IL-1) composite genotype, i.e. presence of the allele 2 in the gene clusters IL-1A-889 and in IL-1B +3953, and periodontitis progression and/or treatment outcomes. MATERIAL AND METHODS: Based on the focused question, a search was conducted for longitudinal clinical trials comparing progression of periodontitis and/or treatment outcomes in IL-1 genotype-positive (carrying allele 2) and IL-1 genotype-negative (not carrying allele 2) subjects. A search in the National Library of Medicine computerized bibliographic database MEDLINE and a manual search were performed. Selection of publications, extraction of data and validity assessment were made independently by two reviewers. RESULTS: The search provided 122 titles of which 11 longitudinal publications were included. The heterogeneity of the data prevented the performance of a meta-analysis. While findings from some publications rejected a possible role of IL-1 composite genotype on progression of periodontitis after various therapies, other reported a prognostic value for disease progression of the positive IL-1 genotype status. When assessed on a multivariate risk assessment model, several publications concluded that the assessment of the IL-1 composite genotype in conjunction with other covariates (e.g. smoking and presence of specific bacteria) may provide additional information on disease progression. The small sample size of the available publications, however, requires caution in the interpretation of the results. CONCLUSION: Based on these findings, (i) there is insufficient evidence to establish if a positive IL-1 genotype status contributes to progression of periodontitis and/or treatment outcomes. Therefore, (ii) results obtained with commercially available tests should be interpreted with caution.