GAP Australasian-Dentist-May June 2019

Category 66 AustrAlAsiAn Dentist lInICal implant site preparation and implant placement were performed in compliance with modern surgical protocols and in accordance with the manufacturer’s instructions. After placement, cover screw was positioned and the implants were submerged. immediately after positioning, patients were prescribed antibiotic coverage with 2 g of amoxicillin (or 600mg of clindamycin in patients allergic to penicillins) for 6 days. Postoperative pain was controlled with nimesulide 100mg daily for 2 days. Patients were given detailed instructions on oral hygiene and were prescribed chlorhexidine 0.12% mouth rinse twice a day for 6 days. the patients were recalled for suture removal after 10 days. the implants were left to heal submerged for a total period of 4 months, to allow undisturbed healing and achieve osseointegration. After 4 months of undisturbed healing, the patient was recalled for the implant to be uncovered. the cover screw was replaced with the healing abutment, and sutures were positioned. two weeks later, the sutures were removed and an impression was taken for the manufacture of the temporary restoration. the temporary restoration was maintained in situ for 3 months, in order to monitor the response of the implant, as well as the peri-implant tissues, to masticatory load; at the end of this period, the temporary restoration was replaced with the final restoration. the final restorations were metal porcelain, cemented with a zinc oxide-eugenol cement. A periapical radiograph was taken to check on the sealing of the restoration. All patients were included in a follow-up protocol with an annual check-up at one of the scheduled professional oral hygiene sessions. 2.3. Primary Outcome. early implant failure, occurring within 4 months after implant placement and therefore prior to placement of the prosthetic restoration and the functional load of the implant, was the primary outcome studied. early implant failures were divided into two different categories: (a) early failures due to lack of osseointegration and subsequent implant mobility, in the absence of clinical signs of infection; (b) early failures due to infection of the bone tissue around the implant, with inflammation (peri-implantitis) of periimplant tissues and the presence of fistula, pain, swelling, pus and/or exudate, pocket depth >6mm with bleeding, and marginal bone resorption >2.5 mm. 2.4. Statistical Analysis. All the data retrieved from the individual medical records were recorded on a generic 2. Materials and Methods 2.1. Data Collection. All patients who had been treated with Morse-taper connection dental implants (leone implant system, Florence, italy) [3, 8] inserted to support fixed prosthetic restorations in one single dental centre (Gravedona, Como, italy), in the period between January 2003 and December 2015, were evaluated for possible enrolment into this retrospective study. Patients were enrolled into the study if they were over 18 years of age, had good oral and general health, and had not undergone bone regenerative therapy prior to implant placement. the exclusion criteria were incomplete medical records, the presence of specific systemic diseases (uncontrolled diabetes mellitus, immunodeficient states, and bleeding disorders), and the abuse of alcohol and drugs; patients undergoing radiotherapy and chemotherapy and those who were pregnant were also excluded. All the data used for the study were obtained from the medical records of the patients enrolled. the patient data was evaluated; this included gender (male or female), age at time of surgery, history of chronic periodontal disease, smoking habits, and serum vitamin D levels. Vitamin D levels were taken from blood tests, which had been requested two weeks prior to surgery. the medical records also contained a range of information as regards the implant or implants, that is, their site (maxilla ormandible), location (incisor, canine, premolar, and molar), the length and diameter of the implant, the type of prosthetic restoration, and the loading conditions. lastly, the medical records contained all the information on any implant failure. these included their cause (lack of osseointegration in the absence of infection, infection of the periimplant tissues or peri-implantitis, or implant failure due to progressive bone loss caused by to prosthetic overload). it also included their classification: early failure, occurring in the early healing period, that is, the four months after implant placement, prior to the placement of restoration and loading, or late failure, occurring after loading. there were also details of any possible biological complications (periimplant mucositis and peri-implantitis) and/or prosthetic complications (mechanical and/or technical). 2.2. Insertion Protocol for the Implants. All implants were inserted under the same strict protocol by the same specialist (C. M.) who had 25 years’ experience in implant dentistry, in the period between January 2003 and December 2015. the implants were inserted after raising a full thickness mucoperiosteal flap; the transformed into its active form, known as either calcitriol or 1,25-dihydroxyvitamin D3 [11, 12]. this active form exerts its action on various tissues by binding to the vitamin D receptors and regulating the transcription of specific target genes [12–23]. serum levels of vitamin D in the 25(OH)D form are the most accurate way of determining vitamin D status: a subject with <10 ng/ml is considered to be vitamin D deficient; one with 10–30 ng/ml is considered to have low levels of vitamin D. the optimal blood level of vitamin D is a value >30 ng/ml [12, 13]. Vitamin D deficiency is high in the general population [12]: in italy, for example, it is estimated that about 80% of people can be deficient, particularly in the northern regions where exposure to the sun is lower [20]. this deficiency increases with age and encompasses the majority of the elderly population of italy who are not taking vitamin D supplements [20]. until a few years ago, the guidelines estimated that the daily intake of vitamin D required to maintain adequate blood levels was 200 iu (5 mcg) in adults aged between 19 and 50, 400 iu (10mcg) in adults aged between 51 and 69, and at least 600 iu (15mcg) in those over 70 [12, 13]. these guidelines have now been revised upwards and it is currently believed that the amount of vitamin D which should be taken daily is 2000iu (50mcg) and up to 4000 (100mcg) in the case of, for example, pregnant women [12, 13]. there is now substantial literature on the negative effects of low levels of vitamin D, especially in severely compromised patients: vitamin D deficiency seems to be associated with increased mortality, cardiovascular events, and reduced functioning of the immune and musculoskeletal systems [15–19, 21–23]. On the other hand, normalizing levels of vitamin D can lead to substantial benefits for critically ill patients, with effects on the muscles, the respiratory system, the heart, and the immune system [18, 21, 23]. Despite the importance of vitamin D and its effects on bone metabolism [11, 12] few studies have, to date, investigated the effects of its depletion on the osseointegration of dental implants [9, 24–35]: almost all these studies have been done on animal models [24–32] and very few on humans [33–35]. the purpose of this retrospective study was therefore to investigate any possible correlation between low blood levels of vitamin D and early implant failure (failure occurring in the four months prior to the full restoration of the implant, because of a lack of osseointegration or because of infection).