[Reconstraction of severe anterior maxillary ridge atrophy: combination of several surgical techniques].

Achieving an esthetic and functional implant supported restoration in the maxillary anterior segment can be challenging especially in a severe atrophy. The reconstruction of atrophic alveolar ridges using autologous Onlay Bone Grafting (AOBG) was originally reported in 1975. It's still considered as the 'gold standard' bone-grafting material, as if combines all properties required in a bone graft material; osteogenesis, osteoinduction, and osteoconduction. The use of intraoral donor sites, such as the mandibular symphysis, and ramus, offers no cutaneous scarring, minimal discomfort, and less morbidity compared with the extraoral sources. In addition, intraoral sites comprises good bone quality, convenient surgical access, good incorporation with a short healing time, high biocompatibility and embryological proximity. Furthermore, recent studies describe extensive bone deficiency reconstruction using solely intraoral block bone grafts by means of the multities technique, possibly by re-harvesting bone from the same donor site. the anatomic configuration in the atrophic site, influences the surgical choices, i.e. when surgical reconstruction is performed in the anterior atrophic maxilla, the reference standard of care would be to perform subnasal augmentation procedure for vertical augmentation with additional vertical and/or horizontal AOBG augmentation if necessary. For the AOBG to be accepted in the augmented area, other elements are introduced for support and rehabilitation; Growth Factor (GFs) for example, are expressed during different phases of tissue healing and are therefore a key element in promoting tissue regeneration. Platelet Rich Plasma (PRP) is an inexpensive way to obtain many GFs in physiological proportion and therefore has gained wide interest as a therapy for both soft and hard tissue injuries. In addition, Platelet-Poor Plasma (PPP) is composed of acellular plasma containing fibrinogen and growth factors, and is used as a "biological membrane" to cover the entire augmented area and donor sites that were filled with bone substitutes saturated in PRP or BMAC (Bone Marrow Aspirate Concentrate)as scaffold. Mesenchymal stem cells (originated from the BMAC) can be differentiated into diverse tissues, including bones. It has been suggested that transplantation of autologous stem cells from bone marrow can as well enhance bone healing. Patient satisfaction is a key factor in the success of implant therapy, especially in the anterior maxilla. Defect in the gingival continuity of shape cannot be always compensated by the quality of the dental restoration only. The challenge is that hard and soft tissue augmentation is necessary to achieve a successful result. The challenge is that hard and soft tissue augmentation is necessary to achieve a successful result. The aesthetics of the patient can be improved using sub-epithelial connective tissue graft. The effectiveness of the combined surgical treatment described, is the fact that AOBG, was used fort he severe atrophic anterior maxilla reconstruction. Augmentation of atrophied maxilla through the positioning of horizontal and vertical AOBG, should be considered reliable, safe, and very effective in obtaining apico-coronal and bucco-lingual dimensions improving implant trajectory for high bone graft success rate following a high long-term implant survival rate.

Mandibular block success rate in relation to needle insertion and position: a self-report survey.

AIM: To evaluate possible associations between successful mandibular block injection and location of penetrating the oral mucosa, location of injection on the ramus and the needle insertion length. STUDY DESIGN: The study consisted of 101 dentists, of whom, 33 were oral surgeons, 33 certified paediatric dentists and 35 general dental practitioners. The dentists were asked to estimate their rate of success in mandibular block injections, defined as the proportion of their patients for whom only a single carpule was necessary, and to indicate the needle insertion length and the location of the injection on a photograph of a ramus and on a photograph of the oral mucosa. RESULTS: Injecting a single carpule for achieving full anaesthesia in 90% or more of their patients was reported by 79.3 and 57.8% of the dentists treating children and adults, respectively. Of practitioners treating children, experienced dentists (>5 years in occupation) reported higher success rates than did inexperienced ones (p = 0.05). A positive correlation was found between failure rate reported in children, shorter length of the inserted needle (R = 0.356, p = 0.001) and injecting at the central (superior inferior dimension) most anterior quarters of the ramus (p = 0.006; odd ratio = 3.9375). Routine waiting period of more than 5 min after the injection and before operative treatment was associated with higher rates of failure (p = 0.042, χ(2) = 6.335). No correlation was found between the success rates of mandibular block injection and the location of penetrating the oral mucosa in children (p = 0.94), adults (p = 0.57), or between success rates and the target location on the ramus in adults (p = 0.42). STATISTICS: χ(2) test was used to determine the significance of differences among proportions and t test for continuous variables. Pearson's correlation analysis was used to analyse the correlation between the length of the needle inserted in children and adults by the same dentist. CONCLUSIONS: Shorter needle insertion lengths and targeting the injecting to the most anterior quarters of the ramus were positively correlated with failure of anaesthesia in children, according to dentists' reports. A routine waiting period of over 5 min did not increase the success rates of mandibular block injection.

Implant success, survival, and failure: the International Congress of Oral Implantologists (ICOI) Pisa Consensus Conference.

The primary function of a dental implant is to act as an abutment for a prosthetic device, similar to a natural tooth root and crown. Any success criteria, therefore, must include first and foremost support of a functional prosthesis. In addition, although clinical criteria for prosthetic success are beyond the scope of this article, patient satisfaction with the esthetic appearance of the implant restoration is necessary in clinical practice. The restoring dentist designs and fabricates a prosthesis similar to one supported by a tooth, and as such often evaluates and treats the dental implant similarly to a natural tooth. Yet, fundamental differences in the support system between these entities should be recognized. The purpose of this article is to use a few indices developed for natural teeth as an index that is specific for endosteal root-form implants. This article is also intended to update and upgrade what is purported to be implant success, implant survival, and implant failure. The Health Scale presented in this article was developed and accepted by the International Congress of Oral Implantologists Consensus Conference for Implant Success in Pisa, Italy, October 2007.

Anxiety and ability to recognize clinical information in dentistry.

Stress significantly affects a person's cognitive ability to process information. Therefore, we hypothesized that patients' ability to recognize information related to the procedure they are about to undergo will be affected by the stressfulness of the situation (less recognition under a high-stress situation as compared with a low-stress situation). Patients (n = 66) were evaluated for their ability to recognize clinical information supplied on two different occasions: immediately before oral surgery (high-stress condition) and before suture removal (low-stress condition). Dental and state of anxiety and expectation of pain were also assessed. On both occasions, the patients' ability to recognize information correctly was low (less than 50%). Patients recognized significantly less information pre-operatively than before suture removal. State of anxiety, dental anxiety, and expectation to experience pain had a profound effect on their ability to recognize provided information correctly. Apparently, before dental treatment (high or low on stress), patients' ability to process information may be severely impaired.

Prevalence, diameter and course of the maxillary intraosseous vascular canal with relation to sinus augmentation procedure: a radiographic study.

The aim of the study was to characterize the prevalence, diameter and course of intraosseous anastomosis between the posterior superior alveolar artery and the infraorbital artery (bony canal) involved in the sinus floor augmentation procedure. Data from 208 sinuses were analyzed from reconstructed computed tomography (CT) images. The presence of the intraosseous anastomosis in the lateral antral wall was detected using sagittal plane sections, in addition, the intraosseous course and the diameter of the bony canal were examined. The bony canal was identified in 114 (55%) of the 208 maxillary sinuses, with a mean distance of 16.9 mm from the alveolar ridge. From the examined canals, in 7% the diameter was 2-3 mm wide, in 22% 1-2 mm and in 26% it was less than 1 mm wide. Because only in 50% of cases the vessel was large enough to be detected by a CT scan, it is recommended, to place the superior border of the osteotomy up to 15 mm from the alveolar crest in A to C type ridges to avoid penetration of the artery.

[The use of platelet rich plasma (PRP) and platelet rich fibrin (PRP) extracts in dental implantology and oral surgery].

Platelet-rich plasma (PRP), made from autologous blood, is being used to deliver growth factors in high concentration to sites requiring osseous grafting. Growth factors released from the platelets include Platelet-Derived Growth Factor (PDGF), Transforming Growth Factor Beta (TGF-b) and Insulin-Like Growth Factor 1 (IGF-1). These factors signal the local mesenchymal and epithelial cells to migrate, divide, and increase collagen and matrix synthesis. PRP has been suggested for use to increase the rate of bone deposition and quality of bone regeneration when augmenting sites prior to or in conjunction with dental implant placement. There is still lack of scientific evidence to support the use of PRP and PRF in combination with bone grafts during augmentation procedures. Further research is warranted.

[Atrophic ridge augmentation using intra-oral onlay bone grafts--expanding the limits].

Placement of an endosseous implant requires sufficient bone volume for complete bone coverage. There is a growing use of intraoral block bone grafts from intraoral sources. The use of bone from the mandibular symphysis, retromolar area, mandibular ramus, and the maxillary tuberosity can serve as a good treatment alternative for alveolar ridge augmentation with a high success rate for long span augmentation, up to complete jaw augmentation or extensive bone reconstruction. The intraoral block bone graft procedure can be combined with other surgical procedures, such as sinus lift elevation or nasal floor elevation.

Radiological features of central haemangioma of the jaws.

OBJECTIVES: The aim of this study was to evaluate the radiological and clinical features of central haemangioma of the jaws. METHODS: A total of 86 cases (84 from the English-language literature and two new cases) were studied and critically evaluated with emphasis on the radiological features. RESULTS: Age at time of initial diagnosis ranged from 0 to 74 years (mean 23 years, median 17 years). There was approximately equal distribution between females and males. The ratio between the mandible and maxilla was 3.3:1. Of the lesions, 69% were located in the posterior region of the jaws. Lesions were radiolucent in 96% of cases. Of the lesions, 66% were multilocular, 33% unilocular, and 1% not loculated. Borders were described in 41 cases, as well defined in 32% and diffuse in 68%. Tooth resorption was described in 23% of the lesions and tooth displacement in 16%, both more common in the mandible. The inferior alveolar nerve canal was involved in 15% of the mandibular lesions and the sinus in 35% of the maxillary lesions. CONCLUSIONS: Central haemangioma has a marked variability in its radiological appearance and should be considered in the differential diagnosis of many unilocular or multilocular radiolucent lesions of the jaws, especially in the mandible. Some radiographic patterns, such as the spoke-like and sunray appearance frequently described in the literature, are actually extremely rare.

[Smoking as a risk factor for dental implants and implant-related surgery].

Cigarette smoking is known to adversely affect wound healing, and thus may jeopardize the success of dental implantation and implant-related oral surgery. The present study is aimed to present the influence of cigarette smoking on the success and survival of dental implantation as well as on the complication and success of implant-related surgery. We conclude that smokers undergoing both implant-related surgical procedures and dental implantation should be encouraged by their dentists, oral and maxillofacial surgeons, or treating physicians to cease smoking, emphasizing that smoking can increase complications and reduce the success rate of these procedures.

[Preservation of alveolar bone of un-restorable traumatized maxillary incisors for future].

UNLABELLED: Anterior maxillary implantation is a challenging treatment for both the surgeon and prosthodontist due to high esthetic demands in this area. However, it is the most traumatized and most exposed region to habits. Prompt and appropriate management can significantly improve prognosis of many dentoalveolar injuries, especially in young patients. Unfortunately, many traumatized teeth are overtreated or left untreated, which lead to a much more complicated treatment at the time of permanent restoration at adulthood. The facial cortical plate over the roots of the maxillary teeth is thin and porous. Periapical infections, as well as prolonged and stubborn surgical treatments (repeated root end surgeries) can cause resorption of the labial plate, migrate to a more palatal position, and may later require an augmentation procedure prior to implant placement. The treatment-options of traumatized, anterior maxillary, un-restorable fractured root and ankylosed infraocluded teeth, in relation to preservation of the adjacent alveolar bone for future use of dental implantation will be discussed. The recommended treatment of crown-root fracture of permanent incisor includes removal of the coronal fragment and supragingival restoration of the fractured root. In severe cases in which the fracture line positions deeply under the gingival margin, this treatment may be supplemented by gingivectomy and/or osteotomy, as well as surgical or orthodontic extrusion of the root. In young patients, use of these treatment options as temporary treatment to preserve the facial cortical plate is important. Preservation of alveolar dimension will enable implantation after the completion of growth and development. Dento-alveolar ankylosis accompanied by replacement resorption is a serious complication following severe injury to the periodontal membrane. This complication develops mainly following avulsion and intrusion but also following lateral luxation and root fracture. Replacement resorption develops after severe damage to the periodontal ligament cells that cover the root surface. As a result of this damage, the periodontal ligament is replaced by bone tissue, causing ankylosis between bone and tooth. Following ankylosis, resorption of cementum and root dentin occurs. These processes eventually result in replacement of the entire root by bone. In young children it could arrest the growth of the alveolar process and create an infra-occluded tooth, resulting in a severe bony defect that is difficult to correct. In addition, loss of the maxillary incisor leads to serious esthetic and restorative problems, particularly when the trauma occurs at a young age. Therefore, ankylosed teeth should be treated as soon as diagnosed. Alternative treatments include intentional extraction and immediate replantation of the ankylosed tooth to its socket after embedding the tooth and the socket in Emdogain. This treatment is indicated only when the ankylosis or the replacement resorption is diagnosed at an early stage or has affected only a small area of the root. When the resorption is diagnosed at a later stage, auto transplantation of first lower pre-molar to the anterior region or decoronation of the ankylosed tooth may be considered. Decoronation is a simple and safe surgical procedure for preservation of alveolar bone prior to implant placement. It should be considered as a treatment option for teeth affected by replacement resorption. The alternative treatment of surgical extraction of an ankylosed tooth often leads to considerable bone loss and reduced bone volume in the oro-facial dimension. This may later necessitate an augmentation procedure. CONCLUSION: Scrupulous diagnosis of teeth and the alveolar bone after a traumatic injury is necessary. Treatment is multidisciplinary, requiring endodontic, surgical, orthodontic, operative and prosthetic compliance. An individual treatment plan for each patient is necessary. General rule do not apply. Periodic check-up is essential.

[Intraoral autogenous onlay block bone grafting for implant dentistry].

The use of autogenous bone graft with endosseous implant for the reconstruction of alveolar ridge deficiencies has been reported with increasing frequency in the past two decades. These bone grafts were harvested mainly from extra oral sites. Various donor sites have been described in the literature including the calvarium, tibia and iliac crest, the latter being most common. Due to the need for hospitalization, general anesthesia and the great morbidity of surgery associated with these donor sites, alternative intra oral sources for graft harvest have been suggested. The most common sites for, being the mandibular symphysis and the mandibular ramus. For the repair of localized alveolar bone defects these donor sites are advantageous. In addition to the ease of donor site access and minimal morbidity, membranous bone grafts show less resorption, good incorporation and shorter healing times. The use of these bone grafts allow us to correct the alveolar ridge height, width and trajectory prior to implant placement thus not only enable a better surgical success, but also should enhance a better prosthetic results as well.

Immediate versus non-immediate implantation for full-arch fixed reconstruction following extraction of all residual teeth: a retrospective comparative study.

BACKGROUND: Immediate implants placed into fresh extraction sites are considered a predictable and acceptable procedure. The main biological advantage is the preservation of bone height and width. However, there is no direct proof of the clinical and surgical importance of this. The purpose of this study was to evaluate the correlation between implant dimensions, anatomic factors, and survival rates of immediate versus non-immediate implants. METHODS: From 1989 to 1996, 380 implants (117 immediate and 263 non-immediate) were placed in 43 patients (50 jaws) following extraction of all residual teeth. A total of 253 implants were placed in the maxilla and 127 in the mandible, with a mean of 7.65 and 7.9 per jaw, respectively. Of the implants, 31% were placed immediately into fresh extraction sites. RESULTS: Total 5-year cumulative survival rate (CSR) was 92%, mandibular 96% and maxillary 90%. Immediate implants had a better 5-year CSR (96%) versus non-immediate implants (89.4%). The maxilla mainly contributed to this difference (95% versus 88%). The mean potential contact surface area (PCSA) was 230 mm2. Implants with significantly higher values yielded a higher 5-year CSR in the maxilla (96.6% versus 82.9%). Immediate implants in the posterior maxilla had a 100% 5-year CSR versus 72% with the non-immediate implants. CONCLUSIONS: 1) Implant-supported fixed ceramo-metal prosthesis is a predictable treatment modality for edentulous patients; 2) factors favorably affecting the survival of implants placed to support full-arch ceramo-metal prosthesis include immediate implantation, higher PCSA values, and implant location; 3) immediate implantation exerts its effect through higher PCSA values and by a compensatory effect to bone quality; 4) immediate implantation does not carry additional morbidity; and 5) potential contact surface area (PCSA) is a reliable mean that accurately represents implant dimensions and may replace length and diameter in future studies.

The clinical effectiveness of implants placed immediately into fresh extraction sites of molar teeth.

BACKGROUND: Studies concerning immediate implantation describe its use in the anterior and premolar regions. However, its clinical effectiveness in immediately replacing molar teeth has rarely been challenged. The purpose of this study was to evaluate the survival rate of implants placed immediately after extraction of molar teeth to support a fixed ceramo-metal prosthesis. METHODS: From 1989 to 1996, 56 immediate implants were placed in 43 patients following extraction of 51 molars; 46 molars were replaced by 1 implant and 5 molars replaced by 2 implants. All implants were restored with fixed prostheses (4 single crowns and 52 splinted). Mean follow-up period was 15 months (range, 4 to 60 months). The influence of the following parameters on implant failure was evaluated: gender, arch, smoking, pre-extraction vertical bone loss, implant length, and severity of complications between the two stages of surgery. RESULTS: The 5-year cumulative survival rate (5-year CSR) was 89%. The 5-year CSR among men was 84% compared to 93.5% among women. The maxillary 5-year CSR was 82% and the mandibular 92%. Among non-smokers (50 implants), the 5-year CSR was 90% compared to 83% among smokers (6 implants). Complications were evident in 8 (6 minor, 2 major) out of 50 non-failing implants compared to 2 (minor) of the 6 failing implants. No differences were evident in the other study variables. CONCLUSIONS: Immediate implantation in the molar region is an alternative, predictable surgical treatment. Immediate implantation in the posterior mandible has a better prognosis than in the posterior maxilla.

The challenge of endosseous implants placed in the posterior partially edentulous maxilla: a clinical report.

The survival rate of implants placed in the maxillary molar area in a 2-stage procedure was evaluated. Between 1990 and 1997, 60 consecutive patients (32 females and 28 males, mean age 51 years) received 87 implants to replace missing maxillary molar teeth. Radiographs were evaluated preoperatively for bone quantity (mesiodistal width, potential implant length not compromising the integrity of adjacent vital structures). Second-stage surgery was performed in a mean of 7.9 months postimplantation. The 5-year cumulative implant survival rate and the influence of implant characteristics (type, length, diameter, and coating) on implant failure and complication rates (between the 2 stages of surgery) were evaluated. The total 5-year cumulative survival rate was 95.4% (4 implants were lost). There were a total of 17 "complications" (premature spontaneous implant exposure) in non-failing implants, 11 with high and 6 with flat cover screws, respectively. Implantation in the edentulous maxillary molar area is a predictable procedure with a considerably high survival rate. The type of implant cover screw used can affect the complication rate.

Odontogenic cysts related to pulpotomized deciduous molars: clinical features and treatment outcome.

OBJECTIVE: The purpose of this study was to assess the morbidity and outcomes associated with large cysts that developed in conjunction with pulpotomized deciduous molars. STUDY DESIGN: This retrospective study was based on the files of 18 patients who were referred to 2 oral surgery departments during a 10-year period (1986-1996). The inclusion criteria were large cyst lesions (>1 cm in diameter) and complete documentation. Data regarding symptoms at presentation, histologic and radiologic features, treatment modalities, morbidity, and outcomes were analyzed. RESULTS: An equal gender distribution of patients was found, as were a later development in males (12+/-2 years in boys, 9+/-2 years in girls) and a 5:1 ratio favoring the mandible over the maxilla. Treatment included enucleation (12 patients) and marsupialization (6 patients). The morbidity was high and included loss of permanent teeth (3 patients), extensive loss of alveolar bone (3 patients), use of flaps (2 patients), and adjuvant orthodontic treatment (9 patients). CONCLUSION: Failure of early detection and treatment of cysts that develop in conjunction with pulpotomized deciduous molars can cause considerable morbidity. Therefore, periodic clinical and radiologic follow-up until the eruption of succedaneous teeth is recommended.

Single tooth replacement of missing molars: a retrospective study of 78 implants.

As experience with osseointegrated implants has grown, greater use has been made of placement in the posterior jaw. The aim of this study is to present the survival rate of 78 osseointegrated single implants, inserted in the molar area and to evaluate the prosthetic rehabilitation on these teeth. This retrospective study presents findings of 55 consecutive patients with 78 restored single osseointegrated implants in the molar area. The patients went through a clinical and radiological evaluation. The same maxillofacial surgeon inserted all implants. Three of the implants were inserted into the maxilla and 75 into the mandible; 4 of the 78 implants were immediate implants. The cumulative survival rate after one year was 93.6%. Follow-up was up to 80 months, with an average of 27 months. Out of all the implants, 6 failed (7. 7%): 5 failed in the surgical stage, and 1 after prosthetic loading. The main implant failures were among the titanium screw implants. Prosthetic complications occurred in 11 cases (14%), which included loosening of the abutment and/or the crown (9 cases), fracture of the abutment (1 case), and porcelain fracture (1 case). No incident of implant fracture occurred. Within the limits of this study, replacement of a single molar by a single implant is a valid and successful surgical treatment modality, with a high survival rate.

Full-arch restoration of the jaw with fixed ceramo-metal prosthesis: late implant placement.

BACKGROUND: The completely edentulous patient has few treatment options in conventional dentistry. When implants are considered, treatment plans range from a 2-implant overdenture to a completely implant-supported prosthesis. Fixed prosthesis is often the preferred selection of the edentulous patient. This study assesses the 5-year cumulative survival rate of implants placed to support full-arch fixed restoration. METHODS: During 1990 to 1995, 171 implants were placed in 22 completely edentulous jaws of 20 patients. All patients were discharged wearing immediate dentures. The implants were analyzed as to the number of implants per jaw, implant location, length, and diameter. RESULTS: The 5-year cumulative survival rate was 89.9%. The mean number of implants per jaw was 7.7 for the maxilla and 8 for the mandible. In the maxilla, the preferred implant locations were the canines, centrals, laterals, and first premolars; in the mandible, they were the canines, laterals, and first molars. The mean implant length was 14.2 mm for the mandible and 13.2 mm for the maxilla. The mean implant diameter was 3.6 mm for the maxilla and 3.8 for the mandible. CONCLUSIONS: The results of the present study indicate that fixed full-arch ceramo-metal restorations can be a predictable implant treatment modality for the edentulous patient.

Full-arch restoration of the jaw with fixed ceramometal prosthesis.

Between 1990 and 1995, 214 implants were placed in 29 maxillae and mandibles of 22 patients following extraction of all residual teeth as a consequence of severe periodontal disease. All patients were discharged wearing immediate dentures. The implants were analyzed with regard to the number per arch, location, length, and diameter. The 5-year cumulative survival rate was 98.5%. The mean number of implants per arch was 7.5 for the maxilla and 7.2 for the mandible. The preferred implant locations were canines, central incisors, lateral incisors, and second premolars in the maxilla; and lateral incisors, first molars, and canines in the mandible. The mean implant length was 14.7 mm in the mandible and 14.5 mm in the maxilla. The mean implant diameter was 3.8 mm in the maxilla and 3.8 mm in the mandible. The results of the present study indicate that immediate implantation for fixed full-arch reconstruction can be considered a viable treatment alternative in patients with severe periodontal disease.

Immediate implant placement: a procedure without incisions.

Primary socket closure in immediate implantation may be difficult, due to the opening left by the extracted tooth. The absolute need for bone augmentation and primary flap closure for implants placed into fresh extraction sites has never been proven. The hypothesis of the present study was that immediate implants can succeed without primary flap closure. A technique that does not require any incisions during immediate implant placement is described. No barrier membranes were used and the sole grafting material used were autogenous bone chips. Full soft tissue coverage was achieved 1 week to 2 months postimplantation. Clinical osseointegration was achieved with minimal gingival recession and papillae preservation. Immediate implant placement in the anterior maxilla can be successful for replacing a single tooth even without primary closure.

The ways and wherefores of immediate placement of implants into fresh extraction sites: a literature review.

A waiting period of 12 months or longer to allow total socket healing used to be accepted protocol for placing dental implants. More than 15 years of research and clinical practice were needed for the concept of immediate endossceous implantation into fresh extraction sites to be accepted. Today the dilemma is no longer when, but which, protocol to follow. The diverse recommendations found in the literature leave the practitioner confused as to the methodology of choice. The conclusions drawn after reviewing the relevant literature on immediate dental implantation are: 1) implants placed into fresh extraction sockets have a high rate of survival, ranging between 93.9% to 100%; 2) implants must be placed 3 to 5 mm beyond the apex in order to gain a maximal degree of stability; 3) implants should be placed as close as possible to the alveolar crest level (0 to 3 mm); 4) there is no consensus regarding the need for gap filling and the best grafting material; 5) the use of membrane does not imply better results-on the contrary, membrane exposure may carry complications in its wake; and 6) the absolute need for primary closure remains to be established.