Delayed immediate implants: alveolar bone chamzes durinrr the healing period

Abstract

Delaying the placement of immediate fixtures by 6-8 weeks after extraction of the natural dentition allows for the elimination of associated infective processes, the achievement of maximum osteoblastic activity that theoretically could help the osseointegration process and complete wound covering that simplifies the placement of grafts or membranes. This study examines the healing associated with 21 fixtures in 14 patients. The fixtures were placed into sockets 6-8 weeks after tooth extraction without the use of barrier membranes or bone substitutes. Measurements were taken immediately prior to fixture placement and 3-6 months later at the abutment placement. Alveolar bone height, the remaining socket depth and diameter and the depth to which a 3.75 mm fixture could be inserted into the socket were measured. After fixture placement the vertical and horizontal measurements from the cover screw to the surrounding alveolar bone and the distance from the cover screw to the CEJ of the adjacent tooth were recorded. All fixtures were integrated at exposure with 1 failure during the follow-up period. The distance from the cover screw to the buccal plate decreased by a mean of 2.17 mm. There was an increase in the mean vertical bone height at all 4 surfaces. When horizontal defects were present, the mean vertical distance decreased from 2.5 +/- 0.37 mm to 0.36 +/- 0.64 mm. When horizontal defects were absent, the mean vertical distance decreased from 3.86 +/- 0.58 mm to 0.48 +/- 0.25 mm. There was also a marked decrease in the horizontal distance between the bone margin and the surface of the fixture from 1.6 +/- 1.73 mm to 0.02 +/- 0.02 mm. These results indicate a strong tendency for the defects to fill-in the horizontal plane and for bone growth to occur in the vertical plane to the height of the cover screw. In conclusion the delayed immediate placement of fixtures has a good short-term prognosis with bone regeneration occurring around the defect without the use of barrier membranes or bone substitutes.

A prospective clinical study of bone augmentation techniques at immediate implants

“…In these studies, initial defect heights ranged from 2.4 to 8.4 mm. In contrast, percentage height reductions of over 85% were noted at implants placed using a 'delayedimmediate' protocol 4-6 weeks after extraction (Nir-Hadar et al 1998;Nemcovsky et al 2002). The enhanced result is likely to be because of the larger size of the initial defects in the current study sample (mean initial defect height of 9 mm).…”

Immediate/Early Function of Neoss Implants Placed in Maxillas and Posterior Mandibles: An 18‐Month Prospective Case Series Study

“…Even more important is the need to maintain the marginal bone level and, consequently, the soft tissue level too, in the front areas of the arches where the aesthetics play a fundamental role. It has been demonstrated that the positioning of an implant in a fresh extraction site can prevent the resorption, especially on the buccal side where the bone is generally thinner 24–25 …”

Dental Extractions and Preservation of Space for Implant Placement in Molar Sites

“…Traditional protocols for restoring these sites rely on bone deposition to fill the extraction site before the implant is placed. 5,6 Hard and soft tissue grafting often is necessary to provide an ideal functional and esthetic restoration. Grafts compensate for the bone resorption that accompanies the natural healing process in an extraction socket.…”