Biomedical subjects

Poliana M Duarte

Publications and source records attributed to Poliana M Duarte.

3 recordsLinked to original sources

PubMed2006

Smoking modulates interferon-gamma expression in the gingival tissue of patients with chronic periodontitis.

Although interferon-gamma (IFN-gamma) plays a critical role in periodontitis, no information is available regarding the effect of smoking on this cytokine in the periodontium. Therefore, this study aimed to evaluate the effect of smoking on the IFN-gamma levels in gingival tissue from patients with chronic periodontitis. Sixty-two patients were assigned to three groups: healthy [non-smoking and periodontally healthy individuals (probing depth or= 5 mm and bleeding on probing; n = 25)]; and smoking [smokers (>or= 1 pack/day for at least 10 yr) diagnosed with chronic periodontitis (n = 25)]. Gingival biopsies were analyzed by quantitative polymerase chain reaction and enzyme-linked immunosorbent assay. Regardless of smoking status, diseased patients presented higher levels of IFN-gamma than peridontally healthy patients. In sites with comparable types of periodontitis, smoking increased both protein and mRNA levels of IFN-gamma in gingival tissue. Within the limits of this study, it can be concluded that modulation of periodontal tissue destruction by smoking may involve its effect on IFN-gamma production.

Adult↗

PubMed2003

A comparative study on the effect of nicotine administration and cigarette smoke inhalation on bone healing around titanium implants.

BACKGROUND: A series of isolated studies has focused on the influence of smoking on bone around titanium implants. This study proposes to investigate the impact of two conditions, i.e., nicotine administration and cigarette smoke inhalation, on the healing around implants. METHODS: Forty-five Wistar rats were used. After anesthesia, the tibiae surface was exposed and a screw-shaped titanium implant was placed bilaterally. The animals were randomly assigned to one of the following groups: Group 1: control, n = 19; Group 2: intermittent cigarette smoke inhalation, n = 15; and Group 3: subcutaneous administration of nicotine (3 mg/kg) twice daily, n = 11. After 60 days, the animals were sacrificed. The degree of bone-to-implant contact (BIC) and the bone area (BA) within the limits of the threads of the implant were measured in the cortical (zone A) and cancellous bone (zone B) areas. RESULTS: In zone A, cigarette smoke presented a significant negative influence on BIC and BA (Kruskal-Wallis test, P < 0.05). In contrast, the administration of nicotine did not influence either parameter (P > 0.05). In zone B, cigarette smoke inhalation also resulted in a decreased percentage of BIC compared to the control group (P < 0.05). In addition, the BA was significantly decreased in groups 2 and 3 when compared to controls (P > 0.05). CONCLUSION: The negative impact of smoking on implant outcomes may be related to more than one molecule present in the cigarette smoke and nicotine seems to partially contribute, especially in the cancellous bone.

Animals↗

PubMed2002

Nicotine and bone density around titanium implants: a histometric study in rabbits.

This study investigated the influence of nicotine on bone density around titanium implants inserted in rabbits. Thirty-two New Zealand rabbits were included. After anesthesia, the tibiae surfaces were exposed and two screw-shaped, commercially available, pure titanium implants of 7.0 mm in length and 3.75 mm in diameter were placed bilaterally. A total of 128 implants were inserted: 64 blasted with Al2O3 particles (group 1) and 64 with a machined surface finish (group 2). The animals were randomly assigned to one of four treatment subgroups, and daily subcutaneous injections of nicotine were administered. After 42 days, the animals were killed and undecalcified sections were prepared. The bone density was measured in the cortical passage of the implant. Statistical analysis (two-way analysis of variance) revealed no significant difference neither regarding the effect of nicotine nor the effect of surface design on bone density around the implants (P > 0.05). Within the limits of the present study, it can be assumed that daily nicotine administration may not statistically influence bone density around titanium implants.

Aluminum Oxide↗