Effect of cigarette smoke inhalation and estrogen deficiency on bone healing around titanium implants: a histometric study in rats.
BACKGROUND
It has been shown that cigarette smoke inhalation (CSI) and estrogen deficiency (OVX) may affect bone quality around titanium implants; however, their association has not been evaluated. Therefore, this study aimed to verify the effects of CSI associated with OVX on bone healing around titanium implants.


METHODS
The tibia surface of 45 female Wistar rats was surgically exposed, and screw-shaped titanium implants were placed. The animals were randomly assigned to OVX (ovariectomized rats; n = 15), SHAM (sham-operated rats; n = 15), and CSI + OVX (4 months of intermittent cigarette smoke inhalation, starting 2 months before implant placement in ovariectomized rats; n = 15). The implants were placed at the time of OVX or SHAM surgery. After 60 days, the animals were sacrificed and undecalcified sections obtained. The percentages of mineralized tissue (bone density [BD]) in a 500-microm-wide zone lateral to the implant, bone filling (BF) within the limits of the threads, and bone-to-implant contact (BIC) were measured in cortical (zone A) and cancellous (zone B) bone.


RESULTS
In zone A, the CSI + OVX group showed a significant difference regarding BIC and BD (P <0.05) compared to the other groups. In zone B, data analysis showed that the CSI + OVX group presented the lowest percentage of BD and BIC, followed by the OVX and SHAM groups, respectively (P <0.05).


CONCLUSIONS
Within the limits of the present study, it can be concluded that cigarette smoke inhalation amplified the deleterious effects of estrogen deficiency, affecting both preexisting and newly formed bone in the cortical and cancellous bone around titanium implants.
Carvalho
Marcelo Diniz
MD
Department of Prosthodontics and Periodontics, Division of Periodontics, School of Dentistry at Piracicaba, State University of Campinas, São Paulo, Brazil.
Benatti
Bruno Braga
BB
César-Neto
João Batista
JB
Nociti
Francisco Humberto
FH
da Rocha Nogueira Filho
Getúlio
G
Casati
Marcio Zaffalon
MZ
Sallum
Enilson Antonio
EA
D000818:Animals; D015519:Bone Density; D004967:Estrogens / Q000172:deficiency*; D005260:Female; D020007:Implants, Experimental; D016348:Osseointegration / Q000502:physiology*; D010052:Ovariectomy; D010053:Ovary / Q000502:physiology; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D013977:Tibia; D014025:Titanium; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*
D004967:Estrogens; D014028:Tobacco Smoke Pollution; D014025:Titanium