The Relationship between Biofilm and Physical-Chemical Properties of Implant Abutment Materials for Successful Dental Implants

The aim of this review was to investigate the relationship between biofilm and peri-implant disease, with an emphasis on the types of implant abutment surfaces. Individuals with periodontal disease typically have a large amount of pathogenic microorganisms in the periodontal pocket. If the individuals lose their teeth, these microorganisms remain viable inside the mouth and can directly influence peri-implant microbiota. Metal implants offer a suitable solution, but similarly, these remaining bacteria can adhere on abutment implant surfaces, induce peri-implantitis causing potential destruction of the alveolar bone near to the implant threads and cause the subsequent loss of the implant. Studies have demonstrated differences in biofilm formation on dental materials and these variations can be associated with both physical and chemical characteristics of the surfaces. In the case of partially edentulous patients affected by periodontal disease, the ideal type of implant abutments utilized should be one that adheres the least or negligible amounts of periodontopathogenic bacteria. Therefore, it is of clinically relevance to know how the bacteria behave on different types of surfaces in order to develop new materials and/or new types of treatment surfaces, which will reduce or inhibit adhesion of pathogenic microorganisms, and, thus, restrict the use of the abutments with indication propensity for bacterial adhesion.     

Host responses induced by different animal models of periodontal disease: a literature review

Periodontitis is an infectious disease characterized by chronic inflammation of the periodontium, and it is mediated and modulated by the host immune system. In the presence of microorganisms or other antigens, immune cells (macrophages/monocytes, dendritic cells, lymphocytes, neutrophils), endothelial cells and fibroblasts secrete cytokines and trigger immune and inflammatory reactions. However, when synthesized at high levels, cytokines modify the pattern of cellular response, participating substantially in the development of chronic inflammatory pathologies, such as periodontal disease. Understanding the origin and progression of bone resorption is one of the primary goals of the field of periodontics, aiming to arrest the disease progression and to optimize future treatments. For this purpose, the development of experimental models is an important and necessary step before entering into clinical trials with new therapies. The purpose of this study is to characterize/evaluate the tissue changes induced by various models of experimental periodontitis through a literature review.     

Trough:peak ratio and smoothness index in the evaluation of 24-h blood pressure control in hypertension: a comparative study between valsartan/hydrochlorothiazide combination and amlodipine

OBJECTIVE: The aim of this study was to measure the time-effect profiles of a once-daily administered valsartan/hydrochlorothiazide combination and amlodipine on blood pressure using various indices derived from 24-h ambulatory blood pressure (BP) monitoring. METHODS: Of the 310 randomized outpatients with uncomplicated mild-to-moderate primary hypertension, 259 (133 on valsartan/hydrochlorothiazide, 126 on amlodipine) were eligible for analysis. After a 2-week placebo wash-out period, the patients were randomly allocated to treatment with either valsartan 80 mg once daily (o.d.) or amlodipine 5 mg o.d. for 4 weeks; in the case of an unsatisfactory blood pressure response, the treatments could be respectively changed to the fixed combination of valsartan 80 mg plus hydrochlorothiazide 12.5 mg o.d. or amlodipine 10 mg o.d. for a further 8 weeks. The trough:peak ratio (global and individualized approaches) and smoothness index (i.e., the ratio between the average of the 24-hourly BP changes after treatment and the corresponding standard deviation) were calculated from 24-h ambulatory blood pressure recordings made after the placebo period and after 4 weeks and 12 weeks of active treatment. RESULTS: Both regimens effectively lowered systolic and diastolic ambulatory pressures after 4 weeks and 12 weeks (all P<0.001) but, among the responders, the valsartan/hydrochlorothiazide combination had a greater antihypertensive effect during the night-time hours after 12 weeks (P=0.03/0.02). In the responders, the placebo-adjusted, mean trough:peak ratios were 0.76/0.74 in the valsartan/hydrochlorothiazide group (n = 111) and 0.66/0.62 in the amlodipine group (n = 101). The corresponding global trough:peak ratios were 0.61/0.57 for the valsartan/hydrochlorothiazide combination and 0.56/0.56 for amlodipine. However, the between-group differences in individual or global trough:peak ratios were not significant. The smoothness index was slightly, but insignificantly, greater for valsartan/hydrochlorothiazide than for amlodipine in the responders and the groups as a whole. CONCLUSION: Valsartan/hydrochlorothiazide and amlodipine were equally effective in reducing ambulatory BP, but the valsartan/hydrochlorothiazide combination led to more homogeneous BP control during the inter-dosing interval. Trough:peak ratio and smoothness index did not reflect this finding accurately.     

Masked hypertension in adults

A body of evidence indicates that masked hypertension is a significant predictor of cardiovascular disease, but how to identify these patients is still a matter of dispute. Data obtained in several cross-sectional studies have demonstrated that masked hypertension is associated with increased left ventricular mass index and carotid intima-media thickness, and impaired large artery distensibility. Furthermore, in longitudinal studies, masked hypertension was a strong predictor of cardiovascular morbidity and mortality. Several factors that can selectively raise ambulatory blood pressure increase the likelihood of having masked hypertension. These include younger age, smoking, alcohol use, contraceptive use in women, sedentary habits and central obesity. In addition, masked hypertension is more common in individuals with high-normal clinic blood pressure or transiently elevated blood pressure. Increased reactivity to daily life stressors and behavioural factors are other important predictors of masked hypertension. In clinical practice, masked hypertension should be searched for in individuals who are more likely to have this condition or are at increased risk of cardiovascular events including those with coronary, cerebrovascular or kidney disease, patients with diabetes and individuals with a high cardiovascular risk profile. To determine whether the use of ambulatory blood pressure monitoring is cost-effective in these individuals, further research is needed.     

Ambulatory versus clinic blood pressure for the assessment of anti hypertensive efficacy in clinical trials: insights from the Val-Syst Study

BACKGROUND: Several studies have found that measurement of blood pressure (BP) in the clinical setting may lead to overestimation of hypertension and may yield inaccurate assessments of the efficacy of antihypertensive treatment. OBJECTIVE: The aim of this study was to determine whether the use of clinic BP in the Valsartan and Amlodipine for the Treatment of Isolated Systolic Hypertension in the Elderly (Val-Syst) study accurately identified those elderly outpatients with systolic hypertension who had true 24-hour elevations in BP, as well as those who required dose increases in antihypertensive therapy during follow-up. METHODS: In Val-Syst, patients aged between 60 and 80 years with a clinic sitting systolic BP (SBP) of 160 to 220 mm Hg and a diastolic BP <90 mm Hg after a 2-week placebo washout period were randomized to receive valsartan 80 mg or amlodipine 5 mg once daily (level 1). In those with a trough SBP > or =140 mm Hg after 8 weeks of double-blind treatment, doses were titrated upward to valsartan 160 mg or amlodipine 10 mg once daily (level 2). If clinic SBP was > or =140 mm Hg after a further 8 weeks, hydrochlorothiazide 12.5 mg was added for an additional 8 weeks (level 3). Clinical decisions during the active-treatment period were based on clinic BP measurements. Thirteen of the 35 participating centers assessed ambulatory BP as well as clinic BP at baseline and the end of the treatment, making it possible to compare the results of the 2 modes of measurement. The Student test was used to compare drug-induced changes in clinic and ambulatory BP in individual patients. Differences between the decreases in clinic and ambulatory BP at the 3 treatment levels were tested using repeated-measures analysis of covariance (ANCOVA), with baseline as the covariate. RESULTS: One hundred sixty-four elderly patients (age range, 60-80 years; 85 men, 79 women) were included in the study (79 valsartan, 85 amlodipine), and valsartan and amlodipine were reported to have comparable effects on the level and rhythm of 24-hour BP In the present study, 22 of 164 patients had white-coat hypertension at baseline (clinic SBP > or =160 mm Hg and mean 24-hour SBP <130 mm Hg). For both treatments combined, the mean (SD) decreases in clinic SBP were inversely proportional to the treatment level (level 1 = -33.2 (7.9) mm Hg; level 2 = -31.6 (11.8) mm Hg; level 3 = -29.3 (11.6) mm Hg; P = 0.001, overall ANCOVA). In contrast, after adjusting for baseline values, the decreases in mean 24-hour SBP did not differ between treatment levels (level 1 = -10.8 [10.4] mm Hg; level 2 = -13.0 [11.2] mm Hg; level 3 = -16.4 [13.8] mm Hg). The decrease in clinic BP during therapy was similar in patients with white-coat hypertension and sustained hypertension (clinic SBP > or 160 mm Hg and mean 24-hour SBP > or =130 mm Hg), whereas 24-hour and 8- to 9-am SBP decreased significantly only in patients with sustained hypertension (P < 0.001). At the end of the study, mean 24-hour SBP continued to be uncontrolled (> or =130 mm Hg) in 16 of 53 patients (30.2%) at treatment level 1, 27 of 62 (43.5%) at level 2, and 19 of 49 (38.8%) at level 3 (P = NS). CONCLUSION: Based on the findings in this population of elderly patients with systolic hypertension, the management of hypertension may vary depending on whether decisions concerning the selection of patients for clinical trials and treatment adjustments during follow-up are made using clinic or ambulatory BP measurement.     

Lip cavernous hemangioma in a young child

Hemangiomas are benign tumors of infancy and childhood, characterized by a phase of fast growth with endothelial cell proliferation, occurring in 10-12% of children at 1 year of age. It is known that hemangiomas of infancy are most commonly located on the head and neck region (around 60% of cases) and occur more frequently in the lips, tongue, and palate. Approximately 50% of hemangiomas have complete resolution, and 90% of them are resolved up to the age of 9. Complications occur in only 20% of the cases, the most common problem being ulceration with or without infection. The treatment depends on lesion location, size and evolution stage, and the patient's age. Surgery is usually indicated when there is no response to systemic treatments, or even for esthetic reasons, being performed as a simple excision in combination or not with plastic surgery. This paper reports a case of lip cavernous hemangioma in a 4-year-old child, who was submitted to 3 sessions of vascular sclerosis due to the size of the lesion, before undergoing simple excision of the hemangioma. Two years of postoperative clinical follow-up shows treatment success with no recurrence of the lesion.