The Role of Immediate Provisional Restorations on Bone Level Implants

The Role of Immediate Provisional Restorations on Bone Level Implants. A Randomised, Single Blind Controlled Clinical Trial

The study is designed to evaluate the clinical and radiographic outcomes of Straumann® Bone Level Implant SLActive placed in healed alveolar ridge (at least 8 weeks post extraction) and immediately provisionalised versus the same type of implants placed in healed alveolar ridge but not provisionalised. In both cases the implants will be loaded at 16 weeks (final restorations). The outcomes will be evaluated over a 2-year period.

This is a prospective, randomised, controlled, single blind, and single center study. The total study duration for each patient should be 24 months.

Straumann Bone Level Ø 4.1 mm SLActive implants will be placed for single tooth replacement, followed by either immediate provisional prosthetic loading or no provisionalised. The final prosthetic loading is made at 16 weeks after implant loading. The implant length will be selected according to the clinical indication of the site based on previous radiographic evaluation.

In total 11 visits per patient are scheduled in this study. Bone level changes, implant success and survival rate, soft tissue changes, aesthetic outcome and adverse events (AEs) will be assessed.

The study devices are CE- (Conformité Européenne, meaning European Conformity) marked products.

One center in the United Kingdom will participate.

Inclusion Criteria:

• General inclusion criteria

  • Males and females, age 18 to 75 years of age (the subjects should be legally able to give informed consent to the procedure; age limitation is also present to avoid inclusion of subjects with incomplete cranio-facial growth).
  • Absence of relevant medical conditions. Patients with contributing medical history in which any elective oral surgical intervention would be contraindicated should be excluded. In particular patients with uncontrolled or poorly controlled diabetes, or unstable or life threatening conditions should be excluded.
  • Absence of uncontrolled or untreated periodontal disease.
  • Absence of untreated caries lesions.
  • Patient in good medical and psychological health as documented by self assessment
  • Patient's availability for follow-up according to the protocol.

• Local inclusion criteria

  • A single tooth replacement is required in the incisor, canine, pre-molar and first molar region. Multiple-implant restorations (non adjacent to the test implant) can be performed during the study (not to be included as test implants).
  • at least 8 weeks post extraction where the soft tissues of the socket have healed
  • Presence of at least one adjacent tooth
  • Presence of adequate native bone to achieve primary stability

Exclusion Criteria:

• General exclusion criteria

  • Patients who have any known diseases (not including controlled diabetes mellitus), infections or recent surgical procedures within 30 days of study initiation.
  • Female patients who are pregnant or lactating or of child bearing potential not using acceptable methods of birth control (hormonal, barriers or abstinence).
  • Patients who are on chronic treatment (i.e., two weeks or more) with any medication known to affect oral status (e.g., phenytoin, dihydropyridine, calcium antagonists, cyclosporine) within one month of baseline visit.
  • Patients who are on concomitant anticoagulant therapy of warfarin (coumadine), clopidogrel, ticlopidine or once daily aspirin of more than 81 mg.
  • Patients who knowingly have HIV or Hepatitis.
  • Physical handicaps that would interfere with the ability to perform adequate oral hygiene.
  • Patients who have undergone administration of any investigational drug within 30 days of study initiation.
  • Alcoholism or chronically drug abuse causing systemic compromisation.
  • Patients who are heavy smokers (>10/cigarettes per day).
  • Patients suffering from a known psychological disorder.
  • Patients who have limited mental capacity or language skills such that study information cannot be understood, informed consent cannot be obtained or simple instructions cannot be followed.
  • Exclude patients with BOP > 30% at the completion of the pre-treatment phase.

• Local exclusion criteria

  • Exclude experimental sites with inadequate bone availability where initial stability of the implant cannot be achieved or extended augmentation procedures and/ or sinus nasal lift are required.
  • History of local radiation therapy.
  • Presence of severe oral lesions.
  • Severe bruxism or clenching habits
  • Patients with lack of posterior occlusion and severely reduced vertical dimension of occlusion
  • Patients presenting clinical and radiological signs and symptoms of maxillary sinus disease in the implant area.
  • Patients presenting an acute endodontic lesion in the neighboring areas to the experimental procedure (sites with presence of an asymptomatic chronic lesion are eligible)
  • Plaque score > 30%