Έλεγχος απορρόφησης περιαυχενικού οστού γύρω από εμφυτεύματα με επικάλυψη αντιμικροβιακού βιοϋμένα

Abstract

Introduction: The incidence of malodor detection at the time of abutment removal reflectsthe accumulation of microbes in the internal spaces of the implant. Bacterial microleakageand colonization in the microgap at the implant abutment interface is believed to play apivotal role in the pathogenesis of infection around implants and the consequent marginalbone resorption. Understanding the aetiological factors, which have been implicated inperiimplant bone resorption and the influence of this marginal bone loss in periimplant softtissues, are considered prerequisites for successful therapeutic outcome.The accelerating bacterial resistance in antibiotics has driven scientific research andinterest in local antimicrobial substances, such as silver. A new implant surface treatmentwith silver biofilm coating in the internal implant surfaces has been developed to preventthe attachment of microbes on the internal surfaces of a dental implant. Silver concentratesall the basic properties that are requested for surface coatings, broad antimicrobialspectrum, high biocompatibility with tissues and the majority of materials used in theproduction of medical devices.Aim: The purpose of this experiment was to evaluate marginal bone resorption at implantswith Ag biofilm coated internal surfaces. The present experiment was further performed tocompare the periimplant tissue dimensions, biologic width, juctional epithelium, connectivetissue, and the distance between the marginal level of bone to implant contact and theimplant abutment connection, the bone implant contact to biofilm treated implants andcontrol implants.Materials and Methods: This study is a double blinded, randomized-controlledexperiment in a canine model. Five beagle adult dogs were used in the experiments. Allmandibular premolars and molars were extracted. After 3 and 5 months of healing, 25 implants with Ag biofilm coated internal surfaces and 25 control implants were installedand connected with the healing abutments in the left and right quadrant of the mandible. Atthe end of a 2 and 4 month period, during which proper plaque control had beenmaintained, biopsies including the implant and the surrounding soft and hard tissues wereobtained.Histology and histomorphometric study of soft and hard periimplant tissues werecarried on undecalfied mesiodistal and buccμlingual ground slides. The histometric analysis included assessment of the vertical dimension of biologic width, juctional epithelium,connective tissue, distance between the marginal level of bone to implant contact and theimplant abutment connection and finally the degree of “bone to implant contact” (BIC %).Statistical analysis was performed to results with Student‟s t-test and Mann-Whitney U test.Results: In mesiodistal sections, after a healing period of 2 and 4 months, the dimensionsof the biological width were 4.03 mm and 4.25 mm for test implants and 4.34 mm and 5.21mm for control implants, respectively. The respective mean values for crestal bone losswere 1.10 mm and 0.74 mm for test implants, and 1.13 mm and 1.49 mm for controlimplants. Statistically significant differences were only observed in the dimensions ofbiologic width and marginal bone resorption in test and control implants, at the 4 monthhealing period (P >0.05).In buccal sections, after a healing period of 2 and 4 months, the dimensions of thebiological width were 4.09 mm and 4.50 mm for test implants and 4.17 mm and 4.48 mmfor control implants, respectively. The respective mean values for crestal bone loss were1.31 mm and 1.02 mm for test implants, and 1.28 mm and 1.29 mm for control implants.No statistically significant differences were present between test and control implants, apartfrom the height of connective tissue at the 2 month healing period (P >0.05).No significant difference in bone to implant contact (%BIC) was found neitherbetween the control and test implants, nor between the 2 healing periods.Conclusions: The histometry showed significant smaller dimensions of biologic width andless bone loss in the test implants. In conclusion, the implant treatment of siver coated internal surfaces resulted in smaller biologic width and may prevent crestal bone loss.Within the limits of this study, the results give a first insight regarding the effectiveness ofantimicrobial properties of silver, before it is used in clinical trials.