The effects of subcutaneous injection of nicotine on osseointegration of machined and anodized implants in rabbits.

Maria Salete Sandini Linden,João Paulo De Carli,Daniela Cristina Miyagaki,Marcos Eugênio de Bittencourt,Luiz Renato Paranhos,Pâmela Letícia dos Santos,Francisco Carlos Groppo,Juliana Cama Ramacciato

doi:10.1590/s0102-865020180010000004

Abstract

To evaluate the influence of subcutaneous injection nicotine in osseointegration process on different implant surfaces. Twenty-two male rabbits were distributed into two groups according to the subcutaneous injections: (1) nicotine 3 mg/day/kg and (2) 0.9 % NaCI 3 mL/day/kg, three times a day; subgroups were then designated-machined and anodized implants were placed in the right and left tibia bones, respectively. The animals were submitted euthanasia after periods of eight weeks to determine nicotine and cotinine levels, alkaline phosphatase and biomechanical analysis. The plasmatic levels of nicotine and cotinine were 0.5 ± 0.28 ng/mL and 9.5 ± 6.51 ng/mL, respectively. The alkaline phosphatase analyses in blood levels in control group were observed 40.8 ± 11.88 UI/L and 40.75 ± 12.46 UI/L, for the surfaces machined and anodized, respectively. In the test group was observed levels 37.9 ± 4.84 UI/L, for both implant surfaces. No significant differences were observed between control and test groups and between the implant surfaces regarding alkaline phosphatase blood levels. For biomechanics, no significant differences were observed in control group between the machined (25±8.46 Ncm) or anodized (31.2 ± 6.76 Ncm) implants. However, the treatment with nicotine induced higher torque than control in both machined (38.3 ± 13.52 Ncm) and anodized (35.5 ± 14.17 Ncm) implants, with p = 0.0024 and p = 0.0121, respectively. Subcutaneous injection of nicotine following implant insertion didn't have effect on osseointegration, independently from the implant surface.

Highlights

Failure to achieve osseointegration of dental implants has been related to several factors, such as poor bone quality and smoking
GraphPad 6.0 was used to perform all tests. This objective to evaluate the effect of nicotine on the osseointegration process data was obtained related to activity of nicotine, cotinine and alkaline phosphatase
No significant differences were observed between control and test groups (p = 0.402) and between the implant surfaces (p = 0.999) regarding alkaline phosphatase blood levels (Figure 3)

Summary

Introduction

Failure to achieve osseointegration of dental implants has been related to several factors, such as poor bone quality and smoking. The addictive element in tobacco, nicotine, has been shown to be of the highest importance when understanding the negative effects of smoking on bones[1]. Studies have isolated nicotine as their exposure agent and assessed its effect of dental implants have found no significant difference in osseointegration between animals with or without exposure to nicotine[2]. It is hypothesized that nicotine, by itself is not able to interfere with the bone healing around titanium implants. Nicotine interferes in the wound healing by causing direct cutaneous vasoconstriction, increasing levels of fibrinogen, hemoglobin and blood viscosity, impairing cellular protein synthesis and the adherence of gingival fibroblasts[3]. It has been demonstrated that nicotine may have beneficial anti-inflammatory effects, which may reduce the symptoms of other systemic inflammatory diseases, such as ulcerative colitis[4]

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