Margaret Hill

Platelet-Rich Plasma–Assisted Guided Bone Regeneration for Ridge Augmentation: A Randomized, Controlled Clinical Trial

BACKGROUND Platelet-rich plasma (PRP) contains a number of biologically active growth factors, and previous studies have reported conflicting ridge augmentation results. The primary aim of this randomized, controlled, masked, clinical trial was to determine if PRP combined with a rapidly resorbing cancellous allograft would enhance the regenerative result compared with an allograft without PRP. METHODS Thirty-two patients with an edentulous ridge defect were sequentially entered into the study; four were excluded from data analysis. Fourteen patients received a cancellous allograft (CAN group) and the other 14 received a cancellous allograft mixed with PRP (PRP group). All 28 grafted sites were covered with a resorbable polylactide membrane. After elevation of a full-thickness flap, horizontal ridge dimensions were measured with a digital caliper at the crest and 5 mm apical to the crest. Vertical ridge dimensions were measured from a tooth-supported stent. All sites were reentered at 4 months, and a trephine core was obtained for histologic analysis before implant placement. RESULTS The crestal ridge width for the CAN group had a mean gain of 2.0 ± 1.2 mm, whereas the PRP group gained 2.9 ± 1.0, and the difference was statistically significant between groups (P <0.05). The percent vital bone was 36% ± 14% for the CAN group compared with 51% ± 15% for the PRP group and was statistically significant between groups (P <0.05). Loss of augmented ridge width was 34% ± 17% for the CAN group and 28% ± 17% for the PRP group (P >0.05). CONCLUSION These clinical and histologic findings suggest that PRP enhanced bone regeneration and resulted in increased horizontal bone gain and percentage vital bone.

Success rate of immediate implants placed and restored by novice operators.

Aims:The primary aim of this study was to evaluate the 1-year crestal bone loss and success rate of an immediately placed single-stage implant placed and restored by novice operators. A secondary aim was to determine the patients assessment of the appearance of the final restoration. Methods:Fifty-one patients received a tooth extraction and placement of at least 1 immediate implant by a Graduate Periodontics resident. Clinical and radiographic measurements were taken at the surgical, 4-month, and 1-year follow-up visits. After at least 3 months healing, dental students restored the implants with either a crown or an overdenture. Patient satisfaction was assessed using 5 categories: excellent, very good, good, fair, or poor. Results:Sixty-two immediate implants were placed. The success rate was 100% at the 12-month visit and was subclassified as grade 3 because of the mean first year bone loss of 1.3 ± 1.0 mm. Using the 2008 classification of Misch et al, 42 implants were classified as success optimum health, 19 as survival satisfactory health, and 1 as survival compromised health. Radiographic bone loss was stratified by implant platform position relative to the alveolar crest and changed from time 0 to time 12 by −1.0 ± 1.2 mm for the supracrestal group (n = 25, P < 0.05), −1.5 ± 0.9 mm for the crestal group (n = 31, P < 0.05), and −1.3 ± 1.2 mm for the subcrestal group (n = 6, P < 0.05). The supracrestal group had significantly less bone loss than either the crestal or the subcrestal group (P < 0.05). The appearance of the final restoration at 1 year was rated excellent by 82% of patients, very good by 16%, and good by 2%. Conclusions:Immediate implant placement by novice operators using routine dental school procedures was a highly predictable procedure as indicated by the 100% success rate at 12 months. Most patients rated the restoration appearance as excellent.

Ridge Preservation Comparing Socket Allograft Alone to Socket Allograft Plus Facial Overlay Xenograft: A Clinical and Histologic Study in Humans

BACKGROUND Previous studies of ridge preservation showed a loss of ≈18% or 1.5 mm of crestal ridge width in spite of treatment. The primary aim of this randomized, controlled, masked clinical trial is to compare a socket graft to the same treatment plus a buccal overlay graft, both with a polylactide membrane, to determine if loss of ridge width can be prevented by use of an overlay graft. METHODS Twelve patients who served as positive controls received an intrasocket mineralized cancellous allograft (socket group), and 12 patients received the same socket graft procedure plus buccal overlay cancellous xenograft (overlay group). Horizontal ridge dimensions were measured with a digital caliper, and vertical ridge changes were measured from a stent. Before implant placement, at 4 months, a trephine core was obtained for histologic analysis. RESULTS The mean horizontal ridge width at the crest for the socket group decreased from 8.7 ± 1.0 to 7.1 ± 1.5 mm for a mean loss of 1.6 ± 0.8 mm (P <0.05), whereas the same measurement for the overlay group decreased from 8.4 ± 1.4 to 8.1 ± 1.4 mm for a mean loss of 0.3 ± 0.9 mm (P >0.05). The overlay group was significantly different from the socket group (P <0.05). Histologic analysis revealed that the socket group had 35% ± 16% vital bone, and the overlay group had 40% ± 16% (P >0.05). CONCLUSIONS The overlay treatment significantly prevented loss of ridge width and preserved or augmented the buccal contour. The socket and overlay groups healed with a high percentage of vital bone.

Ridge Preservation Comparing a Nonresorbable PTFE Membrane to a Resorbable Collagen Membrane: A Clinical and Histologic Study in Humans.

Purpose:The primary aim of this randomized, controlled, blinded clinical trial was to compare the effect of a resorbable collagen membrane (CM group) versus a nonresorbable high-density polytetrafluoroethylene membrane (PTFE group) on the clinical and histologic outcomes of a ridge preservation procedure. Materials and Methods:All 24 sites received an intrasocket cancellous allograft and a buccal overlay bovine derived xenograft. Results:The change in horizontal crestal ridge width was −1.4 ± 1.2 mm for the CM group, whereas the PTFE group lost −2.2 ± 1.5 mm, which was not statistically significant between groups (P > 0.05). Vertical ridge height change was −1.2 ± 1.5 for the CM group, whereas the PTFE group lost −0.5 ± 1.6, which was not significantly different between groups (P > 0.05). The percent vital bone was similar and not significantly different between groups. Primary closure was not obtained and the exposed membrane portion over the socket opening healed with keratinized tissue. Conclusion:The choice of a resorbable versus a nonresorbable barrier membrane did not affect the clinical or the histologic outcome of ridge preservation treatment.