Simultaneous sinus membrane elevation and dental implant placement without bone graft: a 6-month follow-up study

Background: Previous studies have shown that simultaneous elevation of the sinus mucosal lining and placement of dental implants without graft materials can be a predictable procedure. Nevertheless, few prospective, controlled, and randomized studies have evaluated this technique. The aim of this prospective, controlled, and randomized clinical study is to evaluate whether sinus membrane elevation and simultaneous placement of dental implants without autogenous bone graft can create sufficient bone support to allow implant success 6 months post‐surgically. Methods: Sinus membrane elevation and simultaneous placement of dental implants were performed bilaterally in 15 patients in a split‐mouth design. The sinuses were assigned to two groups: the test group, with simultaneous sinus mucosal lining elevation and placement of dental implants without graft materials; and the control group, with simultaneous sinus mucosal lining elevation and placement of dental implants with intraoral autogenous bone graft. After 6 months of healing, abutments were connected. For each implant, length of implant protrusion into the sinus, resonance frequency analysis, and bone gain were recorded at baseline and 6 months follow‐up. Results: Clinical complications were not observed, except for two postoperative fistulas and suppuration in both groups. Only one implant of the test group was lost, reaching a success rate of 96.4% and 100% for the test and control groups, respectively. After healing, radiographic new peri‐implant bone was observed in both groups ranging between 8.3 ± 2.6 and 7.9 ± 3.6 mm for the control and test groups, respectively (P >0.05). Resonance frequency analysis values were lower for the control group compared to baseline (P <0.05). However, these values were similar at 6 months (P >0.05). A significant positive correlation was found between the protruded implant length/bone gain and implant survival/sinusitis (P <0.0001). Conclusion: Implants placed simultaneously to sinus membrane elevation without graft material resulted in bone formation over a period of 6 months.     

上颌窦冲顶提升术同期种植体植入的临床研究

目的 研究上颌窦冲顶提升术不植骨同期植入种植体的临床效果及种植特点。方法 43例患者,牙槽嵴顶距窦底骨高度为5～10mm。经上颌窦冲顶提升术不植骨植入56颗ITI种植体。结果 术后X片显示上颌窦底抬高(2.50±1.70)mm。所有患者未发生上颌窦炎的并发症,种植体稳固,X线片显示骨结合良好。所有种植体术后3～4个月均完成种植修复,可正常负重;种植体存留率100%。结论 在选择好适应证及良好的手术操作配合下,上颌窦冲顶提升术不植骨同期植入种植体可以获得很好的种植成功率。     

Flapless, CBCT-guided osteotome sinus floor elevation with simultaneous implant installation. I: radiographic examination and surgical technique. A prospective 1-year follow-up

Background: Survival rates of implants placed in transalveolar sinus floor augmentation sites are comparable with those placed in non‐augmented sites. Flapless implant surgery can minimize postoperative morbidity, alveolar bone resorption and crestal bone loss. The use of cone beam computerized tomography (CBCT) provides 3D presentations with reduced dose exposure. Objectives: To evaluate a flapless, CBCT‐guided transalveolar sinus floor elevation technique with simultaneous implant installation. Material and methods: Fourteen consecutive patients in need of maxillary sinus floor augmentation were enrolled in this study. Preoperative CBCT with a titanium screwpost as an indicator at the intended implant position was used to visually guide the flapless surgical procedure. Twenty one implants all with a length of 10 mm and a diameter of 4.1 and 4.8 mm were inserted and followed clinically and with CBCT for 3, 6 and 12 months postoperatively. Intraoral radiographs were taken for comparison. All patients were provided with permanent prosthetic constructions 8–12 weeks after implant surgery. Results: Ten (47.6%) implants were inserted in residual bone of 2.6–4.9 mm and 11 (52.3%) implants were inserted in residual bone of 5–8.9 mm. No implants were lost after surgery and follow‐up. There was no marginal bone loss during the follow‐up verified by CBCT. The implants penetrated on average 4.4 mm (SD 2.1 mm) into the sinus cavity and the mean bone gain was 3 mm (SD 2.1 mm). Conclusion: Flapless transalveolar sinus lift procedures visually guided by preoperative CBCT can successfully be used to enable placement, successful healing and loading of one to three implants in residual bone height of 2.6–8.9 mm. There was no marginal bone loss during the 3–12 months follow‐up. To cite this article :
Fornell J, Johansson L‐Å, Bolin A, Isaksson S, Sennerby L. Flapless, CBCT‐guided osteotome sinus floor elevation with simultaneous implant installation. I: radiographic examination and surgical technique. A prospective 1‐year follow‐up.
Clin. Oral Impl. Res. 23 , 2012; 28–34.
doi: 10.1111/j.1600‐0501.2010.02151.x     

Osteotome sinus floor elevation and simultaneous placement of implants--a 1-year retrospective study with Astra Tech implants

Background: The bone support for implants in the posterior part of the maxilla is often poor. This condition may be treated with augmentation of the maxillary sinus floor. The most common technique used is to elevate the sinus floor by inserting a bone graft through a window opened in the lateral antral wall, although less invasive techniques with osteotomes have been used since 1994. Purpose: The aim of this study was to evaluate the clinical and radiographic outcome of implants placed in the posterior maxilla with the osteotome sinus floor elevation (OSFE) technique without grafting. Materials and Methods: The study population comprised 36 consecutive patients in whom 53 implants were inserted with the OSFE technique. The indication for sinus floor elevation was that the bone height below the maxillary sinus was considered to be 10 mm or less. Results: The mean height of the alveolar process in the intended implant sites was 6.3 ± 0.3 mm, and the mean elevation of the sinus floor was 4.4 ± 0.2 mm. At the 1‐year follow‐up, two implants had been lost, both in edentulous patients. The remaining 51 implants inserted were in function, giving a 1‐year cumulative survival rate of 96%. Implants used in single‐tooth replacements and in partially edentulous cases had a 100% survival rate. The mean marginal bone level at the time of loading of the implants was 0.1 ± 0.04 mm below the reference point. One year later, the corresponding value was 0.5 ± 0.06 mm. The mean bone loss between the two examinations was 0.4 ± 0.05 mm. Conclusions: The OSFE technique, without bone grafts, was found to produce predictable results in the treatment of 36 patients with restricted bone volume in the posterior part of the maxilla.     

Simultaneous dental implant placement and endoscope-guided internal sinus floor elevation: 2-year post-loading outcomes

Aims: To determine whether endoscope‐guided sinus elevation procedures can be consistently used to create sufficient bone support for stable implant placement and long‐term implant success. Material and methods: Sixty‐two implants were surgically placed into 30 patients (14 men and 16 women) following internal sinus elevation without the use of graft material. Panoramic radiographs were made pre‐, post‐operative and after 24 months in order to evaluate the peri‐implant bone and maxillary sinuses. Resonance frequency analysis (RFA) was used to evaluate implant stability immediately upon placement and just before prosthesis delivery. Results: The average pre‐operative height of the maxillary alveolar bone was 8.4±2.2 mm at the premolar and 7.3±3.1 mm at the molar regions. The average bone gain was 3.5±1.8 and 4.5±1.9 mm in the premolar and molar sites, respectively. Clinical parameters and the RFA (4 and 12 weeks post‐operative) outcomes show sufficient stability (ISQ=60) of the inserted implants. Three implants failed during the healing period of 12 weeks. The overall implant success rate was 94%. After loading, no further implant failure was observed. The overall success rate after beginning of implant loading was 100%. Conclusions: Sinus floor elevation is a well‐established procedure for augmentation of the atrophic maxillary posterior region. The minimally invasive internal sinus floor elevation procedure visually guided by an endoscope helped to prevent, diagnose and manage complications such as sinus membrane perforation. The clinical outcomes of this study show that endoscope‐controlled internal sinus floor elevation combined with implant placement results in low intra operative trauma, good implant stability upon placement, low incidence of post‐operative symptoms and high success rates after 24 months of loading.     

Bone reformation and implant integration following maxillary sinus membrane elevation: an experimental study in primates

Background: Recent clinical studies have described maxillary sinus floor augmentation by simply elevating the maxillary sinus membrane without the use of adjunctive grafting materials. Purpose: This experimental study aimed at comparing the histologic outcomes of sinus membrane elevation and simultaneous placement of implants with and without adjunctive autogenous bone grafts. The purpose was also to investigate the role played by the implant surface in osseointegration under such circumstances. Materials and Methods: Four tufted capuchin primates had all upper premolars and the first molar extracted bilaterally. Four months later, the animals underwent maxillary sinus membrane elevation surgery using a replaceable bone window technique. The schneiderian membrane was kept elevated by insertion of two implants (turned and oxidized, Brånemark System®, Nobel Biocare AB, Göteborg, Sweden) in both sinuses. The right sinus was left with no additional treatment, whereas the left sinus was filled with autogenous bone graft. Implant stability was assessed through resonance frequency analysis (Osstell^TM, Integration Diagnostics AB, Göteborg, Sweden) at installation and at sacrifice. The pattern of bone formation in the experimental sites and related to the different implant surfaces was investigated using fluorochromes. The animals were sacrificed 6 months after the maxillary sinus floor augmentation procedure for histology and histomorphometry (bone‐implant contact, bone area in threads, and bone area in rectangle). Results: The results showed no differences between membrane‐elevated and grafted sites regarding implant stability, bone‐implant contacts, and bone area within and outside implant threads. The oxidized implants exhibited improved integration compared with turned ones as higher values of bone‐implant contact and bone area within threads were observed. Conclusions: The amount of augmented bone tissue in the maxillary sinus after sinus membrane elevation with or without adjunctive autogenous bone grafts does not differ after 6 months of healing. New bone is frequently deposited in contact with the schneiderian membrane in coagulum‐alone sites, indicating the osteoinductive potential of the membrane. Oxidized implants show a stronger bone tissue response than turned implants in sinus floor augmentation procedures.     

How to avoid intraoperative and postoperative complications in maxillary sinus elevation

Maxillary sinus floor elevation, via the lateral approach, is one of the most predictable bone augmentation procedures performed in implant dentistry. but both intra‑ and postoperative complications can occur, and some of them are severe. Our aim is as follows:

1. To review the pertinent literature on the topic, especially assessing the risk factors related to complications.
2. To give clinical recommendations to minimize intra‑ and postoperative complications with the ultimate scope of improving the standard of clinical care and patient safety.

     

闭合式上颌窦底提升术同期种植体植入临床应用分析

目的探讨采用闭合式上颌窦提升术进行上颌窦底提升及同期种植体植入的效果及技术特点。方法对56例患者共64枚种植体应用骨挤压技术经牙槽嵴顶入路行闭合式上颌窦底提升术及同期种植体植入术。观察方法为临床检查和X线片检查。结果全部患者均在术后6个月完成义齿修复。随访时间8个月-5年,平均19.4个月,发现有3例鼻腔出血;义齿修复后种植体无松动及脱落。术后X线片检查种植区窦底高度平均提升(3.85±0.12)mm,种植体周围无阴影,形成良好的骨结合。结论闭合式上颌窦底提升术较传统的开放式上颌窦提升术简化了手术步骤,缩短了手术时间,减轻了患者术后反应,是一种简单有效的窦底提升技术。     

Long-term changes in graft height after maxillary sinus floor elevation with different grafting materials: radiographic evaluation with a minimum follow-up of 4.5 years

Objective: To compare the vertical dimensional changes with regard to graft height in a long‐term follow‐up in patients treated with two different grafting materials used in maxillary sinus floor elevation procedures. Material and methods: Twenty consecutive patients were included. One group was grafted with autogenous bone from the mandible (chin area), and the other group was augmented with a 100%β‐tricalcium phosphate (β‐TCP). During a 4‐ to 5‐year period, in each patient, at least five panoramic radiographs were made. These panoramic radiographs were used for morphometric measurements, at three different locations. The three locations were the first bone to implant contact at the distal side of the second most posterior implant (L1), halfway between this implant and the most posterior implant (L2) and the site 5 mm distal to the most posterior implant (L3). The measured vertical bone heights were evaluated to assess whether there was loss of height and, if so, whether the reduction in graft height occurred in an initial healing period or whether it was an ongoing process during the whole study period. Results: There is a statistically significant reduction of vertical bone height in time at all locations (P<0.001). The mean decrease of the total vertical height during the whole study period at the three different locations did not differ significantly for and between both grafting groups. Repeated measures analysis of variance showed that at location L1, the reduction in millimeters per month decreased in time (P=0.001). There was no difference between the grafting groups (P=0.958). Similar results were found on L2 (P=0.005). For L3, there also appeared to be a statistically significant difference in reduction in time in millimeters per month (P=0.004). There was no statistically significant difference in height reduction between locations L1, L2 and L3 for vertical bone height and graft height, respectively. Conclusions: Both β‐TCP and mandibular bone grafts resulted in radiographic reduction of the vertical height over the 5‐year period following maxillary sinus floor elevation. After an initial height reduction in the first 1.5 year, subsequent changes were minimal. No significant differences were observed between the two types of grafting material. There was no statistically significant difference in reduction between the three locations for vertical bone height and graft height, respectively.     

A collagenated porcine bone substitute for augmentation at Neoss implant sites: a prospective 1-year multicenter case series study with histology

Background: The presence of localized defects and/or small amounts of bone below the maxillary sinus is a common finding, which may compromise implant placement. There is therefore a need for predictable techniques for bone augmentation in such situations. Purpose: The study aims to clinically and histologically evaluate a porcine bone (PB) substitute used for augmentation of the alveolar crest or the maxillary sinus floor prior to or in conjunction with implant placement. Materials and Methods: Nineteen patients were treated with a porcine bone substitute and barrier membranes (OsteoBiol, Tecnoss Dental, Turin, Italy) for lateral bone augmentation (Group 1a) and healing of bone defects (Group 1b) or for augmentation of the maxillary sinus floor using either a replaceable (Group 2a) or an infractured bone window (Group 2b). A total of 34 implants (Neoss Ltd., Harrogate, UK) were placed in conjunction or 5 to 7 months after the procedure. Implants were followed with implant stability measurements at placement and abutment connection, and with intraoral radiographs at abutment connection and after at least 1 year of loading. A biopsy for histology and morphometry was taken at the first reentry operation. Results: All but one of the procedures was successful (94.7%) as one maxillary sinus procedure (Group 2a) resulted in insufficient bone for implant placement. One of the 34 implants failed, giving an implant survival rate of 97.1% after 1 year. Implant stability measurements showed a mean stability of 71.9 ± 7.7 implant stability quotient (ISQ) at placement, which significantly increased to 75.3 ± 6.8 ISQ at abutment connection (p = .03). The average bone loss was 0.5 ± 0.7 mm during 1 year. Histology revealed new bone formation at the PB surface, which formed bridges between particles and between particles and preexisting bone. The presence of scalloped resorption lacunae and new osteons inside the particles indicated ongoing resorption/remodeling of the particles. The histomorphometric analyses showed that the total specimen area consisted of, in average, 56.5 ± 15.7% mineralized tissue of which 24.8 ± 13.9% of the total area was PB particles. Conclusion: This study showed good clinical results when using a PB substitute and barrier membranes for augmentation of the alveolar crest and maxillary sinus. Histology revealed bone condensation properties and indicated that the material can be resorbed with time.     

Osteotome sinus floor elevation with concentrated growth factor and simultaneous implant placement with or without bone grafting: a retrospective study

The aim of this study was to compare the clinical effects of osteotome sinus floor elevation (OSFE) combined with concentrated growth factor (CGF) and simultaneous implant placement with or without bone grafting in the maxillary posterior region, where the residual bone height (RBH) was 4–6 mm. A total of 44 patients who underwent OSFE combined with CGF and the simultaneous placement of 60 implants (group A, 31 implants with bone grafting; group B, 29 implants without bone grafting) were included in this retrospective study. The clinical indicators of implants were observed for 24 months. Sinus floor lift height was 6.02 ± 0.99 mm in group A and 5.81 ± 0.72 mm in group B (P = 0.360) after surgery. There was no significant difference in the vertical bone resorption between the two groups at 24 months (P = 0.097). Postoperative pain at 14 days (visual analogue scale) was significantly greater in patients with bone grafting when compared to those without bone grafting (P < 0.001). There was no significant difference in marginal bone loss (MBL) between the two groups (P = 0.707 for MBL during the first 12 months, P = 0.922 for MBL during months 12–24). The implant success rate was 100% with or without bone grafting. The technique of OSFE with CGF, either with or without bone grafting, is safe and reliable in patients with RBH 4–6 mm.