Immediate Vs. Early Loading of Immediately Placed Implants

The objectives of the study

The primary objective of this study will be to compare primary and secondary stability between immediate and early loaded, immediately placed bone-level tapered dental implants in the upper jaw in partial and total edentulous patients. The second objective will be marginal bone level changes and soft tissue changes such as keratinised tissue width and gingival thickness which will be assessed at one, two and five years postoperatively. The gained results will assess and compared within partial and total edentulous patients.

Additionally, the study also will be analyse functional and aesthetic outcomes as well as the possibility of the complication and its prevalences including (biological, mechanical, and procedure-related complications) comparing the their incidence between partial and total edentulous patients.

Materials and methods

The study is design as a prospective, randomised, controlled clinical trial which will be conducted at School of Dental Medicine in accordance with the Declaration of Helsinki (World Medical Association, 2013) and the CONSORT Statement.

Before the treatment procedure, after clinical examination patients will be divided into two groups:

• Group A- patient requires on both sides one implant to be placed
• Group B- patient requires full-arch reconstruction

Thereafter, in the both groups, patients will be randomly divided into two subgroups in which immediate loading (test group) or early loading (six week postoperatively) will be performed.

Surgical procedure

One hour before the surgery, antibiotic prophylaxis will be administered, and the patients should rins their mouths with 0.12% chlorhexidine solution for 1 minute preoperatively. The procedures will be performed under local anesthesia using 4% articaine, 1:100.000 epinephrine. A midcrestal incision will be made, and full-thickness will be elevated. Failing tooth or teeth will be extracted using periotomes, elevators, and forceps to preserve socket walls integrity. Extracted alveolus will be immediately prepared following by the epicrestal or subcrestal implant placement. If the gap between the implant surfaces and socket walls is wider than 2 mm, bovine-derived xenograft (Geistlich Bio-Oss®, Wolhusen, Switzerland) and collagen membrane (Geistlich Bio-Gide®, Wolhusen, Switzerland) will be placed. Healing screws (Institute Straumann AG, Basel, Switzerland; NC healing abutment ∅4.8 mm conical 5 mm and RC healing abutment ∅5 mm conical 6 mm) will be placed, and primary wound closure was achieved with 5-0 single resorbable sutures (AssuCryl Lactin, Pully-Lausanne, Switzerland). The presence of apical fenestration, cortical dehiscence, an apico-marginal defect, or the need for contour augmentation will also recorded in the patient study charts. Patients will be prescribed antibiotic therapy for the next five days (Amoxicillin with clavulonic acid, 1 g, twice a day, or, in case of allergy, Clindamycin, 0.6 g, three times a day).

2.3 Prosthetic protocol

Implants in subgroup marked as the test group will be immediately loaded with temporary restorations using S-R abutments (Institute Straumann AG, Basel, Switzerland) whereas the patients from the subgroup marked as control group wouldn't receive any kind of prosthetic restauration, and will left with healing abutments (HA).

For the provisional restoration, an open tray impression technique will be used. Plaster models with scan bodies will be digitized by the laboratory scanner (3Shape E1, 3Shape, Kopenhagen, Denmark), and the virtual design of provisional restoration will be performed with 3D designing software (Exocad-Matera 2.3, Exocad, Darmstadt, Germany). Provisional restorations will be then created using polymethyl methacrylate (PMMA) (Telio®CAD, Ivoclar Vivadent, Schaan, Lichtenstein) and were drilled from PMMA blocks using the 5-axis milling machine (Zenotec Select, Wieland, Pforzheim, Germany). Screw-retained abutments for the prosthetic bridge will be chosen according to implant angulation and surrounding soft tissue height.

At the end of the six-week healing period, definitive prosthetic restorations will be manufactured and delivered to the patients in both groups.

Data Collection and measurements

Implant stability, assessed as the primary study outcome, was measured using the Resonance Frequency Analysis (RFA) method with Osstell Mentor® (Osstell, Gothenburg, Sweden) (Fig. 7b) and Penguin® (PenguinRFA, Gothenburg, Sweden).

Marginal bone loss will be assessed as the difference between the postoperative and followed up years by means of CBCT measurements.

The distance between the implant shoulder and the crestal bone will be estimated as the shortest distance, using the same HA for each patient.

The results will be statistically analysed.

Inclusion criteria

• Adults ≥ 18 years of age;
• systemically healthy;
• periodontally healthy or with stable treated periodontitis and good oral hygiene (FMPS and FMBS ≤ 15%, measured at six sites per tooth)
• Have maxillary dentition with one or multiple failing teeth
• Have sufficient bone volume to immediately place implants
• Non-smoker or light smoker

Exclusion criteria

• An active or chronic disease that affects bone metabolism or wound healing (ASA III type);
• Diminished mental capacities that could mitigate the ability to comply with the protocol;
• History of maxillary augmentation; oral carcinoma or inflammatory changes;
• History of head and neck radiotherapy.