Matteo Chiapasco

Side effects and complications associated with third molar surgery

A retrospective analysis of complications and side effects associated with surgery for 1000 mandibular and 500 maxillary impacted third molars was performed. The analysis included 614 patients with impacted mandibular third molars and 274 with impacted maxillary third molars who were treated in a 5-year timeframe from 1987 to 1992. The incidence of intraoperative complications and side effects of mandibular third molar surgery was 1.1% and 4% for maxillary third molar surgery whereas postoperative complications were 4.3% and 1.2%, respectively.

Maxillary sinus grafting with Bio‐Oss® or Straumann® Bone Ceramic: histomorphometric results from a randomized controlled multicenter clinical trial

INTRODUCTION This investigation was designed to compare the histomorphometric results from sinus floor augmentation with anorganic bovine bone (ABB) and a new biphasic calcium phosphate, Straumann Bone Ceramic (BCP). MATERIALS AND METHODS Forty-eight maxillary sinuses were treated in 37 patients. Residual bone width was > or =6 mm and height was > or =3 mm and <8 mm. Lateral sinus augmentation was used, with grafting using either ABB (control group; 23 sinuses) or BCP (test group; 25 sinuses); sites were randomly assigned to the control or test groups. After 180-240 days of healing, implant sites were created and biopsies taken for histological and histomorphometric analyses. The parameters assessed were (1) area fraction of new bone, soft tissue, and graft substitute material in the grafted region; (2) area fraction of bone and soft tissue components in the residual alveolar ridge compartment; and (3) the percentage of surface contact between the graft substitute material and new bone. RESULTS Measurable biopsies were available from 56% of the test and 81.8% of the control sites. Histology showed close contact between new bone and graft particles for both groups, with no significant differences in the amount of mineralized bone (21.6+/-10.0% for BCP vs. 19.8+/-7.9% for ABB; P=0.53) in the biopsy treatment compartment of test and control site. The bone-to-graft contact was found to be significantly greater for ABB (48.2+/-12.9% vs. 34.0+/-14.0% for BCP). Significantly less remaining percentage of graft substitute material was found in the BCP group (26.6+/-5.2% vs. 37.7+/-8.5% for ABB; P=0.001), with more soft tissue components (46.4+/-7.7% vs. 40.4+/-7.3% for ABB; P=0.07). However, the amount of soft tissue components for both groups was found not to be greater than in the residual alveolar ridge. DISCUSSION Both ABB and BCP produced similar amounts of newly formed bone, with similar histologic appearance, indicating that both materials are suitable for sinus augmentation for the placement of dental implants. The potential clinical relevance of more soft tissue components and different resorption characteristics of BCP requires further investigation.

Clinical outcomes of GBR procedures to correct peri-implant dehiscences and fenestrations: a systematic review

OBJECTIVE To analyze the clinical outcomes of endosseous implants following guided bone regeneration (GBR) procedures to correct dehiscence/fenestration defects associated with implant placement. METHODS/SEARCH STRATEGY: A Medline search was performed for human studies published in English focusing on GBR procedures for the correction of dehiscence/fenestration defects associated with the placement of screw-shaped titanium implants. The selected studies had to include at least 10 consecutively treated patients with a minimum follow-up of 12 months after the start of prosthetic loading. The clinical outcomes in terms of the complication rate of the GBR procedure, implant survival, and stability of marginal soft tissues around implants were evaluated. RESULTS Seven publications were included in this review. A total of 238 patients received 374 implants. Defects were treated with resorbable or non-resorbable membranes, in association with or without graft materials. Patients were followed for 1-10 years after the start of prosthetic loading. In the postoperative period, 20% of the non-resorbable membranes and 5% of the resorbable ones underwent exposure/infection. However, in the majority of cases, a complete or an almost complete coverage of the initial defect was obtained. The overall survival rate of implants, irrespective of the type of membrane and grafting materials, was 95.7% (range: 84.7-100%). No significant modifications of probing depth and/or variation of clinical attachment level around implants were observed during the follow-up period. CONCLUSION Despite the favorable results obtained, it was difficult to draw a significant conclusion as far as the more reliable grafting material and membrane barrier for the correction of dehiscence/fenestration defects are concerned, due to the limited sample of patients and the wide variety of grafting materials and membranes, used alone or in combination. Moreover, due to the lack of randomized clinical trials, it was impossible to demonstrate that such augmentation procedures are actually needed to allow the long-term survival of implants.

The management of complications following displacement of oral implants in the paranasal sinuses: a multicenter clinical report and proposed treatment protocols

This study retrospectively analyses paranasal sinus complications following displacement of oral implants in the maxillary sinus treated according to clinical situation by functional endoscopic sinus surgery (FESS), an intraoral approach, or a combination of both procedures. Over 5 years, 27 patients (13 male; 14 female), aged 27-73 years (mean 53.9 years), underwent treatment for postoperative complications involving the paranasal sinuses following displacement of oral implants in the maxillary sinuses. According to the complication (implant displacement, implant displacement with or without reactive sinusitis and/or with or without associated oro-antral communication), patients were treated with FESS, intraoral approach to the sinus, or FESS associated with an intraoral approach. Follow up lasted for at least 1 year with clinical and radiographic controls. 26 patients recovered completely; one patient underwent re-intervention with FESS and an intraoral approach 2 years after implant removal, due to persistent signs and symptoms of maxillary sinusitis and oro-antral communication. Postoperative recovery after the second procedure was followed by complete recovery. The results demonstrate that a rational choice of surgical protocol for the treatment of complications involving the paranasal sinuses following displacement of implants in the maxillary sinuses may lead to reliable results.

Dental implants placed in grafted maxillary sinuses: a retrospective analysis of clinical outcome according to the initial clinical situation and a proposal of defect classification

OBJECTIVE OF THE STUDY To present a classification of maxillary defects necessitating sinus floor elevation procedures (SFEPs) with two objectives: (a) to propose a standardization of surgical procedures according to initial type of atrophy and (b) to allow the evaluation of the success/survival rates of implants placed in the grafted areas according to the initial situation. MATERIALS AND METHODS Nine-hundred and fifty-two consecutive SFEP were performed on 692 patients. Initial defects were classified according to a new classification, which considered not only residual bone height below the sinus but also the width of the alveolar crest and horizontal/vertical intermaxillary relationship. Results were evaluated according to the different classes. The sinuses were grafted with autogenous bone taken from intra-oral or extra-oral sites: 579 SFEP were associated with vertical and/or horizontal onlay grafts to correct concomitant alveolar ridge deficits. A total of 2037 implants were inserted into the grafted sinuses either immediately or 4-6 months later. Three to 6 months afterwards, implants were loaded. The mean follow-up was 59 months (range: 12-144 months). RESULTS The success rate of the reconstructive procedures varied between 93.2% and 100%, according to class of atrophy; the overall survival and success rates of implants were 95.8% and 92.5%, respectively, whereas the survival and success rates according to class of atrophy varied between 90% and 97.6%, and between 85.4% and 95.5%, respectively. Lower success rates were found in classes presenting with more severe atrophy. CONCLUSION The results obtained demonstrated that sinus floor elevation, alone or in association with reconstructive procedures with autogenous bone grafts, is a reliable procedure to allow implant placement in atrophic edentulous maxillae, irrespective of the initial clinical situation. However, it must be underlined that the success rates of reconstructive procedures and implants differ according to class of atrophy, showing lower success rates in classes presenting with more severe atrophy.

Germectomy or delayed removal of mandibular impacted third molars

PURPOSE To analyze and compare complications and side effects after removal of 1,500 mandibular impacted third molar teeth in three age groups. MATERIALS AND METHODS The sample comprised 868 patients, 462 women and girls and 406 men and boys aged 9 to 67 years. The patients were divided according to age into the following three groups: group A, aged 9 to 16 years; group B, aged 17 to 24 years; group C, older than 24 years of age. RESULTS The incidence of complications and side effects was 2.6% in group A, 2.8% in group B, and 7.4% in group C. All complications were temporary except in one instance of mandibular nerve paresthesia that occurred in a group C patient, in whom symptoms were still present 25 months after surgery. CONCLUSION This study showed no significant difference in the complication rate between groups A and B, but complications significantly increased in group C.

Endosseous implants for prosthetic rehabilitation in bone grafted alveolar clefts

The authors report their experience in the surgical and prosthetic rehabilitation of three patients affected by sequelae of cleft lip and palate, with residual alveolar cleft and absence of maxillary anterior teeth. The patients were treated by means of late secondary bone grafting of the alveolar cleft, followed by the insertion of endosseous titanium plasma-sprayed implants (IMZ). After a further healing period (6-12 months) fixed dental prostheses were constructed. Preliminary results from this series have shown how dental prostheses supported by endosseous implants in grafted alveolar clefts are a very reliable possibility in dental rehabilitation of this malformation.

Failures in Jaw Reconstructive Surgery with Autogenous Onlay Bone Grafts for Pre-implant Purposes: Incidence, Prevention and Management of Complications

Dental rehabilitation with oral implants has become a routine treatment modality in the last decades, with reliable long-term results. However, insufficient bone volume or unfavorable intermaxillary relationships may render implant placement impossible or incorrect from a functional and esthetic viewpoint. Among the different methods for the reconstruction of deficient alveolar ridges, the use of autogenous bone blocks represents the most frequently used treatment modality both for limited and extended bone defects. Prerequisites for a successful outcome are represented by accurate preoperative planning, proper reconstructive procedure, and adequate prosthetic rehabilitation. Even if all these principles are followed, complications involving the grafts may occur, such as dehiscence, infection, or relevant resorption of the graft. The aim of this article is to present an updated overview on the incidence, prevention and treatment of these complications.

Oral implants placed in bone defects treated with Bio‐Oss®, Ostim®‐Paste or PerioGlas: an experimental study in the rabbit tibiae

OBJECTIVES To compare the histological features of bone filled with Bio-Oss, Ostim-Paste or PerioGlas placed in defects in the rabbit tibiae by evaluating bone tissue composition and the integration of titanium implants placed in the grafted bone. MATERIAL AND METHODS Two cylindrical bone defects, about 4 mm in diameter and 6 mm in depth, were created in the tibiae of 10 rabbits. The defects were filled with either Bio-Oss, PerioGlas, Ostim-Paste or left untreated, and covered with a collagen membrane. Six weeks later, one titanium sandblasted and acid-etched (SLA) implant was inserted at the centre of each previously created defect. The animals were sacrificed after 6 weeks of healing. RESULTS Implants placed in bone previously grafted with Bio-Oss, PerioGlas or Ostim-Paste obtained a larger extent of osseointegration, although not statistically significant, than implants placed in non-grafted bone. The three grafting materials seemed to perform in a similar way concerning their contribution towards implant osseointegration. All grafting materials appeared to be osteoconductive, thus leading to the formation of bridges of mineralized bone extending from the cortical plate towards the implants surface through the graft scaffold. CONCLUSIONS Grafting with the above-mentioned biomaterials did not add any advantage to the osseointegration of titanium SLA implants in a self-contained defect.

Methods to treat the edentulous posterior maxilla: implants with sinus grafting.

Prosthetic rehabilitation of the edentulous posterior maxilla with implant-supported prostheses frequently presents a challenge for the oral surgeon because of the lack of bone due to alveolar ridge resorption or maxillary sinus pneumatization. To overcome these problems, different solutions were proposed over the years, such as the use of short implants or tilted implants (including zygoma implants), with the aim of avoiding maxillary sinus floor elevation. Both of these techniques have advantages and disadvantages that should be evaluated carefully to choose the most appropriate treatment. Zygoma implants or short/tilted implants are not a panacea for the treatment of patients with inadequate posterior maxillary bone stock. Instead, treatment should be based on the characterization of resorption patterns of the posterior maxilla, and may include the need for sinus grafting or other grafting procedures to reestablish not only adequate bone volume for implant placement, but also a favorable intermaxillary relationship, to optimize the functional and esthetic outcome of the final prosthetic rehabilitation. The authors discuss the indications, advantages, and disadvantages of sinus-grafting procedures in association with or without other reconstructive procedures.