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S u c c e s s , s u r v i v a l a n d f a i l u r e r a t e s o f d e n t a l i m p l a n t s Introduction The use of dental implants is considered a revo- lution in modern dentistry.1 However, there are differences between professional and patient objectives.1 While the patient is usually concerned with esthetics and function, dental professionals expect success regarding biological and mechan- ical stability and the facilitation of oral hygiene.2 There is consensus among authors that the success of dental implant treatment depends on the presence and maintenance of surrounding bone, mainly in the bone crest area. However, one of the major challenges encountered in im- plantology is the process of bone resorption around the implant after insertion or during its use. In the literature, bone resorption of approx- imately 1.2 mm in height during the first year of function is reported, with 0.1 mm more resorp- tion for every subsequent year.3 This loss with a V or U shape has been called saucerization.4 In 1986, Albrektsson et al. established the following criteria for implant success:5 The im- plant should have no mobility and demonstrate no radiolucent areas radiographically, annual vertical bone loss after the first year should be less than 0.2 mm, and there should be no per- sistent and/or irreversible symptoms. The most common parameter used in clinical reports is the survival rate, indicating whether the dental implant is physically in the mouth or has been removed.6 However, with this method, implants that should be removed owing to pain or illness may be retained and erroneously considered successful. In 1993, an implant quality of health scale was created by James and developed by Misch.7, 8 This scale was later modified at the Interna tional Congress of Oral Implantologists’ Pisa Consen- sus Conference in 2007, presenting four clinical categories that contain conditions of success, survival and failure of the implant. Survival can be divided into two categories: satisfactory sur- vival, which describes implants with less than ideal conditions, but for which there is no need for clinical intervention; and compromised sur- vival, which includes implants with less than ideal conditions requiring clinical treatment to reduce the risk of implant failure. Implant failure is the term used for implants that require removal or that have been lost. Implant success is a term used to describe clinical conditions and must include at least a 12-month period for im- plants serving as prosthetic abutments. Early success is suggested for implants that are re- tained for a period of one to three years, inter- mediate success for three to seven years and long-term success for a period longer than seven years. In this new approach, pain, mobility, ra- diographic bone loss, probing depth and periim- plant disease are evaluated.9 Regarding periimplant disease, since the bone loss caused by stress or bacteria leads to the deepening of the sulcular gap and decreas- es oxygen tension, anaerobic bacteria become the primary promoter of continuous bone loss.9 Exudate or an abscess around an implant indi- cates exacerbation of periimplant disease and possibly accelerated bone loss. Exudate persist- ing for more than one or two weeks normally requires surgical intervention in the periimplant area to eliminate the etiological factors.9 The reduced bone height after the exudate episode exposes the implant to secondary occlusal trauma. The dentist should re-evaluate and reduce the stress factors for the new bone con- dition to improve the performance in the long term.9 Considering the importance of maintenance of the crestal bone around dental implants, the aim of this study was to evaluate the success, survival and failure rates of implants placed over three years based on the implant quality of health scale of the Pisa Consensus Conference. Materials and methods This study included 19 patients who received im- plants and prostheses on implants in the Implan- tology Clinic at the School of Dentistry of Ribeirão Preto of the University of São Paulo, Ribeirão Preto, Brazil, between 2007 and 2013. The pa- tients were recalled for clinical and radiographic examinations from three to six years after implant placement. The following criteria were evaluated by in- terview and dental record analysis: age, sex, presence of systemic disease, history of smok- ing, area in which the implant was placed, im- plant diameter and height, and type of prosthe- sis seated. For the analysis of implant diameter, the following classification was used: narrow when the diameter was less than 3.5 mm, reg- ular when the diameter was 4.0–4.8 mm, and wide when the diameter was greater than 5.0 mm. Regarding height, implants were clas- sified as short when they were less than 10 mm, regular when 10–12 mm, and long when great- er than 12 mm. Journal of Oral Science & Rehabilitation Volume 3 | Issue 2/2017 25