Journal of Oral Rehabilitation 1999 26; 495 – 502 Polymetallism and osseointegration in oral implantology: pilot study on primate B. FOTI*, P. TAVITIAN*, A. TOSELLO*, J.-J. BONFIL* & J.-C. FRANQUIN † *Unite ´ de Recherche Evaluative en The ´rapeutique et Sante ´ Bucco -dentaires, Service d’Odontologie, Ho ˆpital Nord and † Laboratoire Interface Matrice Extracellulaire Biomate ´riaux, Faculte ´d’Odontologie, Marseille, France analysis consists of X spectrometry by dispersion of SUMMARY In oral implantology, successful results in energy which enables a spectral analysis of selected osseointegration are obtained in the medium term points below the crestal neck of the implant (vulner- (6 – 12 months) with commercially pure titanium im- plants. However, current superstructures can be of a able area in the case of corrosive attack) to be obtained. It is noted that after 6 months, two of different nature (precious metal or titanium) and of different manufacture (cast or machine-produced). which were of activation, osseointegration did not vary according to the nature of the superstructure Polymetallism between the implant and the super- structure may lead to conditions of galvanic corro- (precious alloy or titanium). After 2 months, the presence of a precious alloy superstructure lead to sion, and influence osseointegration. The study described establishes, on the one hand, the proce- titanium migration towards the area around the dures of animal experimentation in primates and on cervical region of the implant (10–50 m). This phe- the other, the techniques of analysis of histological nomenon did not occur with a titanium implant. It sections. The first technique of analysis is based on can therefore be presumed that polymetallism leads histomorphometry and leads to the definition of an to detectable corrosion after 2 months but without osseointegration index. The second technique of apparent modification of osseointegration. Introduction During the fitting of endo-osseous implants, three fac- tors are considered essential: (i) close contact between the bony site and the im- plant during its insertion to ensure satisfactory primary immobilization; (ii) a cicatrization period of several months before introducing function; and (iii) a surface whose condition contributes to a fa- vourable biological response. The adherence to such principles helps successfull os- seointegration (Hansson, Albrektsson & Bra ¨ nemark, 1983; Deporter et al., 1986; Keller, Young & Natiella, 1987; De Lange & Donath, 1989; Lum et al., 1988; Sisk et al., 1992). The increasing use of endo-osseous implants to sup- port dental prostheses calls for continued dynamic ex- perimental studies as earlier recommended in 1988 by the NIH and the NIDR (Rizzo, 1988a,b).There is a need to evaluate the differences which may exist concerning the nature of oral tissue in relation to the different implant schemes and material. The widespread use of metal-framed prostheses on implants has led to an increase in certain failures which have been clinically recorded in the years fol- lowing the fitting of prosthetic superstructures. These have been mainly the fracture of the osseointegrated implants (Balshi, 1996). The possibility of changes af- © 1999 Blackwell Science Ltd 495