The evolution of preimplant surgery from preprosthetic surgery

Patients' appreciation of pre-implant augmentation of the severely resorbed maxilla with calvarial or anterior iliac crest bone:a randomized controlled trial

Background

Little is known about the impact of bone graft harvesting for pre-implant augmentation of the maxilla from a patient’s perspective. To assess patient-reported outcome measures (PROMs) related to augmentation of the extremely resorbed edentulous maxilla with calvarial or anterior iliac crest bone.

Materials and methods

For this randomised controlled trial, 20 consecutive edentulous patients needing extensive pre-implant surgery of the maxilla were randomly assigned to either calvarial (n = 10) or anterior iliac crest (n = 10) bone harvesting. Patient reports on procedure-related satisfaction, questionnaires on oral functionality (denture satisfaction, chewing ability) and oral health-related quality of life (OHIP-49NL) and subjective donor site-related outcomes (e.g. of post-operative pain, scar formation, physical mobility) were assessed.

Results

Irrespective of the harvesting site, patients were generally satisfied (median VAS score 93 (86–99) mm, p = 0.400) with the procedure and its final results. Post-operative pain was mild (median 40 (20–40) mm) and decreased to no pain (4 (0–16) mm) within 14 days. Early post-operative pain was significantly higher following anterior iliac crest harvesting (p < 0.00). Impact on physical mobility, daily functioning and satisfaction with the scar formation were similar in both groups.

Conclusions

The assessed PROMs confirmed that bone graft harvesting from the calvarium or anterior iliac crest is an appropriate procedure, reflected by high levels of satisfaction, minor long-term sequela and improvement of perceived oral health. For clinical decision-making, decisions can be based on individual features and preferences.

Trial registration

NTR, NTR3968, registered 1 July 2013.

One-Stage Vertical Ridge Augmentation and Dental Implantation With Allograft Bonerings: Results 1 Year After Surgery

The aim of this study was to analyze the success rate of dental implants and the graft shrinkage rate after vertical ridge augmentation and simultaneous implantation with an allograft bonering. Fifty-one patients (81 augmentations and simultaneous implantations) were included. The bonering technique followed a standardized protocol. The alveolar ridge was prepared using a congruent trephine, and depending on the defect size, an allograft bonering with an outer diameter of 6-7 mm was placed. The height of the bonering was trimmed with a diamond disc to the required length. The average height of vertical augmentation was 5.5 mm. Implants were inserted through the bonering into the native bone of alveolar ridge. After 6 months, dental implants were exposed, and dental prosthetics were placed. Of 81 implants placed with the bonering technique, two failed during a 12-month follow-up, corresponding to a success rate of 97.5%. One year after surgery, the allograft bonering exhibited an average vertical graft shrinkage rate of 8.6%. In conclusion, the allograft bonering technique was associated with a favorable outcome, and in cases with large vertical defects, both treatment time and donor site morbidity could be reduced.

Alveolar Ridge Splitting Versus Autogenous Onlay Bone Grafting: Complications and Implant Survival Rates

PURPOSE

To compare the complications and implant survival rates of localized alveolar ridge deficiencies in the horizontal dimension reconstructed by alveolar ridge splitting (ARS) or autogenous onlay bone grafting (OBG).

MATERIALS AND METHODS

Twenty-eight ARS and 28 OBG were performed. The survival rate of the all included implants was evaluated using the clinical and radiographical evaluation criteria of Misch et al. Temporary exposure of graft, mild infection, temporary paresthesia, and bad split were defined as minor complications; permanent exposure of graft, loss of graft, and permanent paresthesia were defined as major complications. Major and minor complications of ARS and OBG groups were statistically compared.

RESULTS

When the minor and major complication rates are considered, there was not any statistically significant difference between OBG (P = 0.099) and ARS (P = 0.241) groups. The satisfactory survival rate of OBG group was 92% and was 100% in the ARS group, and the difference was not statistically significant (P = 0.116).

CONCLUSION

When reconstructing vertically sufficient but horizontally insufficient alveolar ridges, ridge splitting technique could shorten the treatment period, decrease postoperative swelling and pain, eliminate the need for a second surgical site, reduce the treatment cost, and ease the patient cooperation to the surgery.

Efficacy of PRP in the Reconstruction of Mandibular Segmental Defects Using Iliac Bone Grafts

This retrospective study was conducted to evaluate the role of platelet-rich plasma (PRP) in the reconstruction of segmental mandibular defects using iliac bone grafts. Thirteen patients underwent reconstruction of post-resection segmental defects of the mandible using titanium reconstruction plates, cortico cancellous iliac bone graft. The patients were randomly separated into two groups. One group of the patients received a PRP graft in addition to the iliac bone graft. Post-operative dimensions of the graft were measured and compared to assess the efficacy of PRP in reconstruction of segmental defects. The post-operative follow-up radiographs confirmed consolidation of the graft in all cases and the segmental defect was obliterated. Thereby mandibular continuity was successfully achieved in all cases. Two patients in the non-PRP group developed an infection and were administered additional antibiotics. The infection was contained and the grafts survived. The use of PRP along with autogenous bone graft may be advantageous since it appeared to enhance the quantity of bone formed. Further long-term follow-up and studies are required to effectively establish the efficacy of PRP and autogenous free bone grafts in the reconstruction of bony defects.

Influence of a collagen membrane and recombinant platelet-derived growth factor on vertical bone augmentation in implant-fixed deproteinized bovine bone--animal pilot study

OBJECTIVES

Combinations of bone substitute block materials with membrane techniques as well as with growth factors are possible options to enhance the prognosis of vertical bone augmentation. Therefore, the aim of the pilot study was to compare the influence of a collagen membrane and a signal protein (rhPDGF-BB) on vertical bone augmentation with a stable fixed block material (deproteinized bovine bone [DBB]).

MATERIALS AND METHODS

In 12 rabbits, a DBB-block was implant-fixed on the tibia in a split-leg-design. Included were: DBB only (control), DBB + collagen membrane (test), DBB + rhPDGF-BB (test) and DBB + rhPDGF-BB + collagen membrane (test). 24 samples were examined after 3 (n = 12) and 6 weeks (n = 12). Calculated parameters were new bone area (NBA;%), new vertical bone height (VBH; mm). Due to the pilot character of this study, single values are shown descriptively only.

RESULTS

After 3 weeks, there were constant higher NBA values in the rhPDGF-BB-group without membrane (NBA (%) DBB: 30/16/4; DBB + membrane: 25/17/7, DBB + rhPDGF-BB: 40/33/34, DBB + rhPDGF-BB + membrane: 0/30/16; VBH (mm) DBB: 1.2/1.2/1, DBB + membrane: 0.7/0.9/1, DBB + rhPDGF-BB: 0.7/0.9/1, DBB + rhPDGF-BB + membrane: 0/1.1/1). After 6 weeks, both membrane groups showed a constant higher NBA and VBH independent to the use of rhPDGF-BB (NBA DBB: 3/0/5, DBB + membrane: 20/35/31, DBB + rhPDGF-BB: 5/8/4, DBB + rhPDGF-BB + membrane: 31/35/40; VBH DBB: 0.3/0.3/0.6, DBB + membrane: 1.6/2.4/2.1, DBB + rhPDGF-BB: 0.4/0.7/0.8, DBB + rhPDGF-BB + membrane: 1.8/2/1.8).

CONCLUSIONS

For vertical augmentation, the addition of rhPDGF-BB to DBB-blocks may increase early bone growth. In the later phase, the use of a collagen membrane enhances new bone volume and height to a significant greater extend. Even if the results are higher than those in the non-membrane groups, the low gain of bone after the short time periods still needs improvement.

Simultaneous sinus lifting and alveolar distraction of a severely atrophic posterior maxilla for oral rehabilitation with dental implants

We retrospectively reviewed a new preimplantation regenerative augmentation technique for a severely atrophic posterior maxilla using sinus lifting with simultaneous alveolar distraction, together with long-term oral rehabilitation with implants. We also analyzed the regenerated bone histomorphologically. This study included 25 maxillary sinus sites in 17 patients. The technique consisted of alveolar osteotomy combined with simultaneous sinus lifting. After sufficient sinus lifting, a track-type vertical alveolar distractor was placed. Following a latent period, patient self-distraction was started. After the required augmentation was achieved, the distractor was left in place to allow consolidation. The distractor was then removed, and osseointegrated implants (average of 3.2 implants per sinus site, 80 implants) were placed. Bone for histomorphometric analysis was sampled from six patients and compared with samples collected after sinus lifting alone as controls (n = 4). A sufficient alveolus was regenerated, and all patients achieved stable oral rehabilitation. The implant survival rate was 96.3% (77/80) after an average postloading followup of 47.5 months. Good bone regeneration was observed in a morphological study, with no significant difference in the rate of bone formation compared with control samples. This new regenerative technique could be a useful option for a severely atrophic maxilla requiring implant rehabilitation.