implants - internationalmagazine of oral implantology

I clinical study _ flapless implant surgery Fig. 9_Correlation of AG with PD. Fig. 10_Peri-implant soft tissue before insertion of fixed prosthetic restoration (Straumann). _Discussion The study aimed to assess the long-term clinical outcome of minimally invasive, flapless surgery with a particular focus on the peri-implant soft tis- sue. This longitudinal study investigated whether, withrespecttosofttissue,itispossibletoobtainre- sults comparable to or even better than the stan- dard, more invasive, flap surgery. To date, there is only a limited number of such studies. Three differ- ent implant designs were compared. Ample evi- dence is available documenting the long-term im- plant survival rate of >90% after five years with classical, trapezoidal flap surgery (Behneke et al. 2000; Mericske-Stern et al. 2001; Romeo et al. 2002). Surprisingly, there is limited information on the long-term outcome of the flapless surgical proto- col. Until now, published papers have reported the outcome only up to 18 months (Brodala, 2009). In a multicentre clinical study, Beckeretal. (2009) eval- uated 57 patients. They demonstrated that the re- sults are similar to those obtained with the conven- tional flap protocol. After five years, 37 of these pa- tients were followed up and the survival rate re- mained as high as 98.7%. This is comparable to the result obtained in the present study, with a slightly longer than average follow-up time of three to four (maximumof9.7)yearsand99.6%ofsurvivingand fully functional implants at the time of the last fol- low-up. The predictability of transgingival healing fol- lowing flap preparation has been extensively inves- tigated. Numerous studies concluded that there is no difference between implants that healed in sub- merged or open fashion (Ericsson etal. 1997; Buser etal.1990,1999;Abrahamssonetal.1999;Weberet al.2000).Forflaplesssurgery,despiteamodification of the surgical approach, osseointegration can be achieved in a predictable way (Campelo & Camara 2002; Sclar 2007; De Bruyn et al. 2009; Jeong et al. 2007, 2010; Rousseau 2010). Concerns of a higher failurerate,causedbytheinevitablecontamination of the sterile implant surface by oral bacterial flora, were not confirmed. The results of an animal study proved that contamination of the soft tissue before surgeryhasnonegativeimpactonimplantosseoin- tegration (Ivanoff etal. 1986). Adherence to aseptic conditions during surgery nevertheless remains an important implantation success factor (Adell et al. 1985; Sennerby & Lekholm 1993). Recently, in a controlled retrospective study Rousseau(2010)wasabletodemonstratethatinthe correct indication range the success of minimally invasive transgingival implantation is the same as that of the classical protocol: minimally invasive, 98.3%; conventional, 98.5%. Nevertheless investi- gations of the peri-implant soft tissue following minimally invasive surgery are rare: 24, 44 and 241 patientshavebeenfollowedupoveraperiodoffour to 12 months (Oh etal. 2006; Lee etal. 2009; Jeong etal. 2010, respectively). The influence of keratinised peri-implant AG on the occurrence of peri-implant inflammation is still a controversial issue (Marquez 2004). In this study, arelationshipbetweenAGandimplantsurvivalwas not established. We analysed the PD and BOP clini- calparameters,whichcanbemeasuredinapractice setting with reasonable technical equipment. This comparison should allow the assessment of peri- implant tissue health. An animal study demon- strated that missing AG resulted in significantly in- creased recession and slightly higher attachment loss (Warrer etal. 1995). This result implied that the absence of AG around implants increases plaque- induced tissue damage. The implication was vali- dated in a clinical study (Bouri et al. 2008) of 2008 implants, which remained in situ for at least 12 months.Thepresenceofatleast2mmofAGwasac- companied by minimal alveolar bone loss and im- provementofindicesthatdescribeperi-implanttis- suehealth.Thesamestudydemonstratedthatinthe 14 I implants4_2011 Fig. 9 Fig. 10