Resolution of bone defects of varying dimension and configuration in the marginal portion of the peri-implant bone. An experimental study in the dog.

• BACKGROUND: It was demonstrated that a marginal defect of about 1 mm between the bone wall and the metal surface after implant installation can heal with a high degree of bone fill and osseointegration. Objective: The aim of the present animal experiment was to study bone healing at implant sites with hard tissue defects of varying dimensions and configuration. MATERIAL AND METHODS: Four Labrador dogs were used. All mandibular premolars and first molars were extracted. After 3 months of healing, five experimental sites, two control (C1, C2) and three test (T1, T2, T3) sites, were identified. In all five sites, custom-made implants with a sand-blasted, large-grit, acid-etched (SLA) surface and with an outer dimension of 3.3x10 mm, were used. In site C1, traditional implant installation was performed. In site C2, the marginal 5 mm of the canal, prepared for the implant, was widened to 5.3 mm using a step-drill. Thus, following the installation of the implant, a circumferential gap occurred between the bone tissue and the metal rod that was 5 mm deep and between 1 and 1.25 mm wide. In test site T1, the canal was widened to establish a marginal gap of 2-2.25 mm. In test sites T2 and T3, the marginal 5 mm of the canal was first widened to 5.3 mm (T2) or 7.3 mm (T3). The buccal bone wall opposite the defect was subsequently removed. Following the placement of a cover screw in sites C2, T1, T2, and T3, a resorbable membrane was placed over the defect. All implants were submerged. After 4 months of healing, block biopsies of each implant site were dissected and processed for ground sectioning. RESULTS: The observations disclosed that four-wall defects of different dimensions (1-2.25 mm wide) that occurred in the marginal portion of the recipient sites following implant installation were resolved during healing. Further, at sites where the buccal bone wall during defect preparation was intentionally removed, healing resulted in defect resolution at the mesial, distal, and lingual aspects. At the buccal aspects, healing was incomplete but the dimension of the defect was reduced by the limited amounts of new bone formation extending from the lateral and apical borders of the defect. CONCLUSION: Wide marginal defects may during healing be filled with bone. In such defects a high degree of osseointegration may occur to implants designed with an SLA surface.

Subject headings

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Odontologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Dentistry (hsv//eng)

Keyword

Absorbable Implants

Acid Etching

Dental

Air Abrasion

Dental

Animals

Dental Implantation

Endosseous

methods

Dental Implants

Dental Prosthesis Design

Dogs

Mandible

physiopathology

surgery

Membranes

Artificial

Osseointegration

physiology

Osteogenesis

physiology

Surface Properties

Time Factors

Tooth Socket

physiopathology

surgery

Wound Healing

Publication and Content Type

ref (subject category)

art (subject category)