Evaluation of Using Different Screwed Abutment Height

Not Applicable

Completed

Interventions: Device: Dental implant placement with COVER SCREW (two surgeries in control group) or DEFINITIVE TRANSEPITHELIAL ABUTMENT (one surgery in test group)

Brief Summary: A prospective randomized controlled clinical trial will be conducted. Study groups will be assigned as described above. The patients will be randomly divided into two groups in order to study the influence of prosthetic screw abutment in marginal bone loss (MBL) around Bone Level Tapered implants (BLT® Roxolid® SLActive® guided implants, Straumann Dental Implant System, Institut Straumann AG, Basel, Switzerland).

Detailed Description: 48 patients will be selected with partial edentulism in the maxilla or mandible, requiring two dental implants in the posterior areas (molars and premolars).

Each patient will be randomly allocated in one of the two groups: test group (n=36) or control group (n=12) and all the implants will be placed by residents of the International Master in Oral Surgery and Master in Periodontics of the same University.

Study groups

Group 1: Two stage approach (cover screw in first surgery and healing abutment in second surgery) (12 patients)

Group 2: One stage approach (healing cap over trans-epithelial abutments) (36 patients).Two subgroups according to different trans-epithelial height abutment:

* Subgroup 2.1: Screw-retained abutment of 1 mm height (18 patients)

* Subgroup 2.2: Screw-retained abutment of 2.5 mm height (18 patients)

Clinical Parameters and Outcomes

* Three-dimensional volumetric changes in hard and soft tissues (Cone-beam computed tomography superposed with digital cast models).

* Marginal bone level (MBL) change: Standardized intraoral periapical x-rays will be taken on the day of surgery, 4, 6, 12, 24 and 36 months following surgery.

* Probing depth, bleeding on probing and keratinized mucosa width will be measured in the follow-up visits in 3 different points in buccal (Mesial, center and distal).

* VAS Scale: The visual analog scale or visual analog scale (VAS).

Recruitment & Eligibility

Inclusion Criteria

Exclusion Criteria

Acute local infection
Occlusal overload with parafunctional activity (assessed clinically)
Large occlusal discrepancies
Untreated periodontal disease assessed by Socransky et al. parameters (≥2mm clinical attachment loss in two consecutive visits within 1 year)
Smokers (more than 10 cigarettes/day)
Drug and/or alcoholic dependencies
Medical conditions contraindicating implant surgery
History of head and/or neck radiation
Bisphosphonate therapy

Arm && Interventions

Group	Intervention	Description
Control group	Dental implant placement with COVER SCREW (two surgeries in control group) or DEFINITIVE TRANSEPITHELIAL ABUTMENT (one surgery in test group)	Group 1: 2 stage approach (cover screw) (12 patients): cover screw is placed over the dental implants in the first surgery and a second surgery will be performed to expose the implants and placing a healing abutment after 2-4 months, DEVICES: COVER SCREW (first surgery) and HEALING ABUTMENT (second surgery)
Test group	Dental implant placement with COVER SCREW (two surgeries in control group) or DEFINITIVE TRANSEPITHELIAL ABUTMENT (one surgery in test group)	Group 2: Protective plastic cap over different definitive trans-epithelial abutments are placed in the unic surgery performed (36 patients): Definitive transepithelial abutments will be placed the same day of the implant placement surgery. DEVICE: DEFINITIVE TRANSEPITHELIAL ABUTMENT

Primary Outcome Measures

Name	Time	Method
Marginal bone loss	After implant loading (baseline)and once every year to 36 months follow-up	Periimplant bone level by measuring from the implant platform to the first bone to implant contact. Messuret in 2 points: MESIAL AND DISTAL with intra-oral XR. (measured in millimeters)

Secondary Outcome Measures

Name	Time	Method
Probing depth	After implant loading (baseline)and once every year to 36 months follow-up	Measuring this outcomes at 4 different points .(Mesial Buccal, Center Buccal, Distal Buccal and central lingual) (measured in millimeters).
Bleeding on probing	After implant loading (baseline)and once every year to 36 months follow-up	Measuring this outcomes at 4 different points .(Mesial Buccal, Center Buccal, Distal Buccal and central lingual) (measured in millimeters).
Keratinized mucosa width	After implant loading (baseline)and once every year to 36 months follow-up	Measuring this outcomes at 4 different points .(Mesial Buccal, Center Buccal, Distal Buccal and central lingual) (measured in millimeters).