Implantes Dentales

ARTICLE IN PRESS
Journal of Cranio-Maxillofacial Surgery (2005) 33, 212–217 r 2005 European Association for Cranio-Maxillofacial Surgery doi:10.1016/j.jcms.2004.12.004, available online at http://www.sciencedirect.com

Failed dental implants – clinical, radiological and bacteriological findings in 17 patients$
Pekka LAINE1Ã, Antero SALO1, Risto KONTIO1, Seija YLIJOKI1, Christian LINDQVIST12,Riitta SUURONEN123 Department of Oral and Maxillofacial Surgery (Chair: Prof. C. Lindqvist), Helsinki University Central Hospital; 2Department of Oral and Maxillofacial Surgery (Chair: Prof. C. Lindqvist), Helsinki University, Helsinki, Finland; 3Institute for Regenerative Medicine and Medical School (Chair: Prof. R. Suuronen), Tampere University and University Hospital, Tampere, Finland
1SUMMARY. Aim: The aim of this study was to evaluate the reasons for implant failure in two Oral and Maxillofacial Units in Helsinki. Seventeen patients, who lost 30 implants were included in this study. Material and methods: The patients and implants were studied clinically, radiologically and microbiologically. Results: Most patients did not have any symptom indicating failure; hence, the failureswere noticed mainly by the clinicians when instability of the fixture or of the prosthetic reconstruction became obvious. Radiolucency around the fixture was the most frequent radiological finding. Twenty per cent of the fixtures were located in insufficient bone. Ninety seven per cent of the bacterial cultures were positive, Streptococcus milleri being the most commonly identified aerobic andFusobacterium nucleatum the most commonly anaerobic bacteria. Conclusion: The most critical time for success is immediately after prosthetic loading. Hence, implants should be placed in the optimal position to facilitate prosthetic reconstruction and loading. r 2005 European Association for Cranio-Maxillofacial Surgery

Keywords: dental implants; failing; microbiology; clinical

INTRODUCTION The FinnishDental Implant Register was established in Finland in 1994 to provide a reliable source for patient information needs, for users to support better implant choice, and as background information for administrative decisions. It is obligatory nationwide for every surgeon to provide information about the insertion, as well as the loss or removal of dental implants. It has been estimated that 70% ofthe procedures are being registered, because at the moment there is no sanction for not sending in the information. This registry facilitates long-term follow-up of dental implant treatment in Finland. According to the ‘Finnish Dental Implant Register 1994’, 2653 implants were inserted in Finland in 1994. In 2001 the number of inserted implants was 9210. Altogether 53,110 implants have been insertedin Finland during the period from 1994 to 2001 (Fig. 1). In the maxilla, the most frequent site was central incisor and premolar areas, while in the mandible the first molar area was the most frequent implant site. In 1994, most prosthetic rehabilitation was carried out using removable prostheses, while in 2001, most prosthetic reconstructions were fixed bridges and crowns. During the first years ofthe Register, all age groups were evenly represented, whilst during the last
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few years (1999–2001), most of the implants have been inserted for patients aged 50–59 years. In 2000, according to the Register, 160 implants were reported to have failed. The corresponding figure for 2001 was 214. The most common reason for failure was local infection, followed by unsatisfactory position of theimplant. According to the register, one of the main reasons to remove the implant was injury to the inferior alveolar nerve leading to pain caused by the implant (Pihakari et al., 2002). The first implants in the Helsinki Units were inserted in 1980. Today, approximately 350 implants are being inserted here annually. Contrary to the patient material in the whole Implant Register, where most...