ABSTRACT
OBJECTIVES: The purpose of this study was to evaluate the movement of pure titanium implants under different continuous forces in the edentulous alveolar ridge. MATERIAL AND METHODS: Four pairs of titanium implants were inserted into the right maxillary and mandibular post-extraction edentulous ridge of the experimental dog. Three different levels of continuous force (100, 200, and 500 g) were loaded onto three pairs of adjacent implant abutments using a memory Ni-Ti coil spring for up to 6 months and the remaining two implant abutments as the control group received no force. The positions of implant abutments were observed and the distances between the implants abutment at the top, middle and base levels were measured at the 0th, 2nd, 3rd, 6th and 8th month of the follow-up period. RESULTS: There was no significant change in the distances between adjacent abutments loaded with 100 or 200 g continuous forces throughout the entire study period. However, significantly more movement of implant abutments was noted in the 500 g pair after the 3rd month of loading when compared with the 200 or the 100 g pair (both P < 0.001). This change further increased at the 6th month (P < 0.001, 0.01, respectively). Moreover, the difference in the measurements at the top, middle and base level indicated that the two adjacent implants moved in a tipping manner in the 500 g pair after 3 and 6 months of loading. CONCLUSION: The osseointegrated implants remained stable and rigid with a pulling force of 100 and 200 g after 6 months of loading. However, when the force reached 500 g, the implants moved in an inward-tipping pattern. The results suggested that endosseous titanium implants might not necessarily be rigid anchorages under all circumstances.
Subject(s)
Dental Implantation, Endosseous/methods , Dental Implants, Single-Tooth , Dental Stress Analysis , Orthodontic Anchorage Procedures , Orthodontic Appliance Design , Analysis of Variance , Animals , Dogs , Longitudinal Studies , Movement , TitaniumABSTRACT
BACKGROUND/PURPOSE: Microarrays, or biochips, are a new technology that can allow rapid detection of bacterial genetic materials. To explore their practical applications, we compared use of a microarray for the diagnosis of bacterial meningitis with the traditional blood and cerebrospinal fluid (CSF) culture methods. METHODS: Samples from 50 patients with suspected bacterial meningitis were analyzed by microarray and by traditional blood and CSF cultures. RESULTS: Among all samples, 11 were positive by microarray analysis, seven were positive by CSF bacterial culture and six were positive by blood culture. CSF pleocytosis was found in 26 patients. Of these, eight were positive by microarray analysis, seven were positive by CSF culture and five were positive by blood culture. The percentage of positive results from microarray analysis was 22%, compared to 14% by CSF culture and 12% by blood culture. The CSF bacterial culture method had the highest positive predictive value and specificity (both 100%). The sensitivity of microarray analysis was higher (30.8%) than that of CSF and blood cultures (26.9% and 19.2%). All three methods had a similar negative predictive value in the range of 52.3-55.8%. Of the 11 microarray positive samples, four were identified successfully in CSF culture (36.4%) and three samples were identified in blood culture (27.2%). One of the microarray positive samples was diagnosed as a polymicrobial infection (9%), and the rest were monomicrobial infections. CONCLUSION: The microarray method provides a more accurate and rapid diagnostic tool for bacterial meningitis compared to traditional culture methods. Clinical application of this new technique may reduce the potential risk of delay in treatment.
Subject(s)
Meningitis, Bacterial/diagnosis , Adult , Aged , Aged, 80 and over , Child, Preschool , Female , Humans , Infant , Male , Meningitis, Bacterial/microbiology , Microarray Analysis , Sensitivity and SpecificityABSTRACT
The present study aimed to assess the association between the severity of chronic periodontitis and the risk of gastrointestinal (GI) cancers by investigating whether severe chronic periodontitis (CP), rather than mild CP, correlates with an increased risk of total or individual GI cancers.Adults (≥18 years) with mild and severe CP were identified from a random sample of 2 million insured patients in the National Health Insurance Research Database (2001-2010). After propensity score matching, 25,485 individuals, each with mild or severe CP, were included for comparison. The primary endpoint was the incidence of total or individual GI cancers, including cancers of the esophagus, stomach, small intestine, colon/rectum, and pancreas. Cox proportional hazard models with the robust aggregated sandwich estimator were used to calculate hazard ratios (HRs) and 95% confidence intervals (95% CIs) after adjusting for known risk factors.GI cancers occurred in 275 individuals with mild CP and 324 individuals with severe CP. After adjusting for known risk factors, severe CP was not associated with an increased risk of total GI cancer relative to mild CP (HR: 0.99, 95% CI: 0.84-1.16) or individual GI cancers, including esophageal (HR: 1.15, 95% CI: 0.62-2.15), gastric (HR: 1.01, 95% CI: 0.68-1.49), small intestinal (HR: 0.70, 95% CI: 0.22-2.22), colorectal (HR: 0.95, 95% CI: 0.78-1.16), and pancreatic cancers (HR: 0.90, 95% CI: 0.47-1.75).Severe CP was not associated with an increased risk of total or individual GI cancers when compared with mild CP.
Subject(s)
Chronic Periodontitis/complications , Gastrointestinal Neoplasms/epidemiology , Adult , Aged , Aged, 80 and over , Cohort Studies , Databases, Factual , Female , Follow-Up Studies , Gastrointestinal Neoplasms/etiology , Humans , Incidence , Male , Middle Aged , Propensity Score , Proportional Hazards Models , Retrospective Studies , Risk Factors , Taiwan/epidemiologyABSTRACT
Infective endocarditis (IE) is an uncommon but potentially devastating disease. Recently published data have revealed a significant increase in the incidence of IE following the restriction on indications for antibiotic prophylaxis as recommended by the revised guidelines. This study aims to reexamine the basic assumption behind the rationale of prophylaxis that dental procedures increase the risk of IE.Using the Longitudinal Health Insurance Database of Taiwan, we retrospectively analyzed a total of 739 patients hospitalized for IE between 1999 and 2012. A case-crossover design was conducted to compare the odds of exposure to dental procedures within 3 months preceding hospitalization with that during matched control periods when no IE developed.In the unadjusted model, the odds ratio (OR) was 0.93 for tooth extraction (95% confidence interval [CI] 0.54-1.59), 1.64 for surgery (95% CI 0.61-4.42), 0.92 for dental scaling (95% CI 0.59-1.42), 1.69 for periodontal treatment (95% CI 0.88-3.21), and 1.29 for endodontic treatment (95% CI 0.72-2.31). The association between dental procedures and the risk of IE remained insignificant after adjustment for antibiotic use, indicating that dental procedures did not increase the risk of IE.Therefore, this result may argue against the conventional assumption on which the recommended prophylaxis for IE is based.
Subject(s)
Dental Care/adverse effects , Dental Scaling/adverse effects , Endocarditis/etiology , Adult , Aged , Antibiotic Prophylaxis , Cohort Studies , Female , Humans , Male , Middle Aged , Risk AssessmentABSTRACT
BACKGROUND: The aim of the present study was to identify the long-term major adverse cardiovascular events (MACE) in treated periodontitis patients in Taiwan. METHODS: From the National Health Insurance Research Database (2001-2010), adult patients (≥ 18 years) with treated periodontitis were identified. Comparison was made between patients with mild form and severe form of treated periodontitis after propensity score matching. The primary end point was the incidence of MACE. RESULTS: A total of 32,504 adult patients with treated periodontitis were identified between 2001 and 2010. After propensity score matching, 27,146 patients were preserved for comparison, including 13,573 patients with mild form and 13,573 patients with severe form of treated periodontitis. During follow-up, 728 individuals in mild treated periodontitis group and 1,206 individuals in severe treated periodontitis group had at least 1 MACE event. After adjustment for gender, hyperlipidemia, hypertension and diabetes mellitus, severe treated periodontitis was associated with a mildly but significantly increased risk of MACE among older patients > 60 years of age (incidence rate ratio, 1.26; 95% confidence interval, 1.08-1.46). No association was found among younger patients ≤ 60 years of age. CONCLUSIONS: Severe form of treated periodontitis was associated with an increased risk of MACE among older Taiwanese patients, but not among younger Taiwanese patients. We should put more efforts on the improvement of periodontal health to prevent further MACE.