Long-term Clinical and Radiographic Comparison of Dental Implants with Different Surface Properties Placed in the Posterior Region

Dental implants have become one of the most common treatments used for the rehabilitation of lost teeth. Dental implant surfaces have been roughened in different ways to increase the degree of osseointegration. A recent review reported that five different types of implant surfaces have been documented over more than 10 years. These surfaces were evaluated in 5 parts: machined, titanium plasma spray (TPS), sprayed, SLA (sandblasted and acid-etched), and anodized. The properties of an implant surface have long been identified as an essential factor in achieving and maintaining osseointegration. Modifications made to the implant body surface aim to support osseointegration and the reduction of bacterial adhesion. Pathogenic microbial colonization can lead to peri-implantitis and peri-implant marginal bone loss, resulting in dental implant failure. Roughness, porosity, and surface chemistry are essential factors for osseointegration. In particular, surface chemistry is vital in increasing cell adhesion.

An example of those produced by rearrangement of the outermost surface layer is the Ti-Unite (Nobel Biocare AG, Zurich, Switzerland) implant, where the oxide thickness is increased, and an anodizing process breaks the boundary between titanium crystals. Ti-Unite was introduced in 2001 and is among the best-selling dental implant surfaces worldwide. Nowadays, the Ti-Ultra (Nobel Biocare AG, Zurich, Switzerland) surface structure is being introduced. This redesigns the surface chemistry and topography to optimize tissue integration at all implant levels. Ti-Ultra is an ultra-hydrophilic, multizone, anodized implant surface with a graduated surface from implant neck to apex. There are studies in the literature comparing different implant surfaces.

The aim of this study is to compare the effects of fixed prosthetic restorations placed in the posterior region with different implant surfaces on clinical and peri-implant marginal bone loss.

The study will be carried out by Kütahya Health Sciences University, Faculty of Dentistry, Department of Periodontology. Systemically healthy patients between the ages of 18 and 99 and patients who have missing teeth in the posterior region and want to have a restoration with a dental implant will be included. Patients will be evaluated in two different groups: test and control groups. Patients were assigned to study groups. It will be distributed randomly and with a sealed envelope method. While dental implants with a Ti-Ultra surface will be included in the test group, dental implants with a Ti-Unite surface will be placed in the control group. All patients will undergo implant surgery and prosthetic restorations with the protocol recommended by the same company. After functional loading, patients will be followed for 12 months and routine clinical evaluations will be performed. Measurements and radiographic examinations will be obtained.

Before the operation, systemic and dental anamnesis will be taken from the patients and clinical measurements will be recorded. Periodontal indices such as plaque index, gingival index, bleeding on probing index and pocket depth will be recorded in both implant groups. Before the operation, the patient's bone amount will be evaluated on cone beam computed tomography and planning will be made. In both implant groups, keratinized mucosal thickness, keratinized mucosal height and vertical mucosal height will be measured in the area where the implant will be placed. Before and during the dental implant treatment operation, mesial, distal, buccal and lingual-palatal bone thickness measurements of the implant socket will be made with a digital caliper. Post-operative (T0), post-prosthetic loading (T1), 6th month (T2) and 1st year (T3) periapical x-rays will be taken. The amount of peri-implant marginal bone loss will be evaluated using software on standardized control periapical radiographs to be taken at the end of one-year follow-up.