Bilateral Sinus Elevation Evaluating Plasma Rich in Growth Factors Technology: A Report of Five Cases

Purpose: The purpose of this study was to evaluate the potential effects of plasma rich in growth factors (PRGF) technology and its autologous formulations in five consecutive patients in which bilateral sinus lift augmentation was carried out. Material and Methods: Five consecutive patients received bilateral sinus floor augmentation. All patients presented a residual bone height of class D (1–3 mm). The effects of PRGF combined with bovine anorganic bone (one side) were compared with the biomaterial alone (contralateral side). The effects of using liquid PRGF to maintain the bone window and autologous fibrin membrane to seal the defect were evaluated. A complete histological and histomorphometrical analysis was performed 5 months after surgery. Results: One patient was excluded from the study as the Schneiderian membrane of the control side was perforated during the surgery. In two patients, the biopsies obtained from the control sides 5 months postsurgery were not acceptable for processing. PRGF technology facilitated the surgical approach of sinus floor elevation. The control area was more inflamed than the area treated with PRGF technology. Patients referred also to an increased sensation of pain in the control area. PRGF‐treated samples had more new vital bone than controls. In patient number 1, image processing revealed 21.4% new vital bone in the PRGF area versus 8.4% in the control area, whereas in patient number 2, 28.4% new vital bone was quantified in the PRGF area compared with the 8.2% of the control side. The immunohistochemical processing of the biopsies revealed that the number of blood vessels per square millimeter of connective tissue was 116 vessels in the PRGF sample versus 7 in the control biopsy. Conclusions: These preliminary results suggest that from a practical point of view, PRGF may present a role in reducing tissue inflammation after surgery, increasing new bone formation and promoting the vascularization of bone tissue.     

压电超声骨刀在23例上颌窦提升术中的应用

目的:总结压电超声骨刀在上颌窦提升开窗手术中的临床应用,探讨其手术特点及术中注意的问题。方法:对符合上颌窦外提升术标准(种植区骨高度为5～8mm)的23例患者(24侧),进行了上颌窦外提升手术,术中应用压电超声骨刀进行上颌窦开窗手术,黏膜提升,填入人工骨粉,同期植入种植体。结果:24侧上颌窦提升手术,其中1侧由于术中操作不当,出现黏膜穿孔,终止手术;其余23侧均成功地进行了上颌窦提升,黏膜穿孔率仅为4.2%,并同期植入种植体48个,愈合期内(手术后10d拆线时)无感染及创口裂开等并发症。结论:应用压电超声骨刀进行上颌窦外提升手术,快捷、安全、可靠。     

改良上颌窦底提升术的临床应用

目的:评价改良上颌窦底提升术在处理上颌后牙区垂直骨量不足中的应用及临床效果。方法:65名上颌后牙缺失患者,共103个植入位点。上颌窦底下方的剩余牙槽骨高度为2～9mm。其中,30例剩余骨高度为5～9mm的患者,采用超声骨刀行上颌窦底内提升术;35例剩余骨高度为2～5mm的患者,行侧壁小开窗上颌窦底提升术。同期或延期植入种植体,随访9-30个月。结果:术后6个月,行上颌窦底内提升术的患者,平均提升高度为4.43mm(2.22～5.47mm);行上颌窦底外提升术的患者,平均提升高度为5.95mm(4.16～12.85mm)。103个种植位点中仅2例在术中发现黏膜穿孔,1例在戴牙后3个月出现种植体松动,其余种植体均形成良好骨结合,存留率为99%。结论:上颌窦底提升术能够有效促进上颌窦内成骨,增加上颌后牙区骨高度,超声骨刀及外提升术中小开窗术式的应用,可显著降低术中并发症的发生率、缩短手术时间、减轻患者术后反应。     

CBCT在侧壁开窗式上颌窦底提升术的临床应用

目的:通过CBCT评估上颌后牙区牙槽骨及上颌窦状况,评价其指导侧壁开窗式上颌窦底提升术的临床效果。方法:以上后牙缺失且经CBCT检查确认,需行上颌窦底提升术的患者46例为研究对象,根据CBCT信息制定手术方案。同期植入种植体85枚,延期植入11枚,术后6⁸月完成上部结构修复,修复后3、6、12月定期复查。结果:手术过程中未出现黏膜穿孔,术后随访中未出现种植体周围黏膜炎、种植体周围炎,种植体松动脱落;X线检查种植体周围骨结合良好,未出现明显骨吸收,患者未诉主观不适。种植手术成功率及随访期间种植体存留率均为100%。结论:CBCT可为侧壁开窗式上颌窦提升术提供全面可靠的指导,术前精确测量与检查,对提高成功率具有重要作用。     

Sinus floor elevation using osteotomes or piezoelectric surgery

The aim of this paper is to describe a technique for sinus floor augmentation with a 1-step crestal approach where the residual bone is ≤7.5 mm. 36 implants were installed in 25 patients in the atrophic posterior maxilla immediately after sinus floor elevation. Sinus floor elevation was performed with a crestal approach using either osteotomes and burs or piezosurgery. Standardized intraoral radiographs were taken prior to surgery and 1 year after surgery. The mean residual bone height was 5.61 mm (range 3-7.5 mm). The mean gain of sinus elevation was 6.78 mm (range 3.5-10 mm) at 1 year after surgery. Two patients dropped out of the study. Of the 23 patients completing the study, one implant failed, whilst the remaining 33 implants were stable 12 months after surgery (cumulative survival rate 97%). A statistically significantly higher bone height was achieved with tapered implants compared with cylindrical implants (P < 0.05). No statistically significant differences were found in bone level using osteotomes or piezosurgery. Piezosurgery was considered to provide less discomfort for the patient and greater convenience for the surgeon.     

Risk factors in lateral window sinus elevation surgery

Maxillary sinus augmentation is the most predictable of the pre‐prosthetic surgical procedures. There are, however, known and well‐documented complications that can and do occur. The most common are the intraoperative complications of sinus membrane perforation and bleeding, and the postoperative complications of sinus graft infections, sinus infections, and sinusitis. The majority of these complications can be prevented, or their incidence greatly reduced, through a thorough understanding of maxillary sinus anatomy, the multifaceted etiologies of these conditions, and the steps that can be taken to avoid them. This volume of Periodontology 2000 will discuss both the preoperative and intraoperative procedures that will prevent these untoward outcomes and the necessary treatment modalities that will limit their adverse effects.     

Palatonasal Recess on Medial Wall of the Maxillary Sinus and Clinical Implications for Sinus Augmentation via Lateral Window Approach

Background: Anatomic variations of the maxillary sinus determine the degree of difficulty in performing sinus augmentation. Whereas some variations, e.g., the septum and morphology of the sinus, have been extensively studied, the structure of the medial wall has never been investigated. The aims of this study are to measure the location and angulation of the palatonasal recess (PNR) on the medial wall and identify risk sites that are related to the shape of the PNR. Methods: Cone‐beam computed tomography (CBCT) scans were screened from the University of Michigan School of Dentistry database. Edentulous sites with <10 mm between the floor of the maxillary sinus and the alveolar crest were selected. The residual ridge height (RH), the distance between the PNR and the alveolar crest, and the angulation of the PNR were measured on the selected sagittal planes. The percentage of sites (risk sites) with recesses that were <90°and <15 mm from the alveolar crest was calculated. The PNR location and angulation were compared among premolar and molar edentulous sites. Results: Two hundred seventy‐four sites were studied. The mean ± SE PNR location was 14.2 ± 2.8 mm, 13.1 ± 2.2 mm, and 12.5 ± 2.5 mm for the second premolar, first molar, and second molar sites, respectively, with significant differences between the second premolar and second molar sites. The mean PNR angulation was 109.8° ± 25.3°, 121.6° ± 22.1°, and 144.9° ± 23.1° in the corresponding sites, with significant differences among the site groups. The respective percentages of risk sites were 15%, 8.2%, and 2.4% in the second premolar, first molar, and second molar sites. Conclusions: Maxillary sinuses with acute‐angled PNRs might present a challenge for performing sinus augmentation. Therefore, this anatomic structure should be carefully evaluated.     

Sinus Elevation with an Alloplastic Material and Simultaneous Implant Placement: A 1-Stage Procedure in Severely Atrophic Maxillae

Aims and objective

The aim of the study is to evaluate clinically and radiographically the long term success of one-stage direct (lateral) sinus lift procedure using alloplastic bone graft material and bio-absorbable membrane in conjunction with two stage implant placement in atrophic partially edentulous posterior maxilla.

Materials and methods

One stage direct maxillary sinus lift in conjunction with two stage implant placement was carried out in 12 patients at 13 sites. All the patients were partially edentulous with posterior maxillary alveolar ridge height of >5 mm and were in the age group of 20–50 years. Bioactive glass putty, bio-absorbable collagen membrane and 3.75 × 11.5 mm implants were used. Loading of implants was done 6 months after placement of implants. Patients were evaluated clinically and radio-graphically 6, 18, 30 months after placement of implants to assess increase in residual ridge height, peri-implant condition (marginal bone loss, plaque and gingival index) and implant stability.

Results

Maxillary first molar was the most common site (69.23 %) for sinus lift and implant placement. Caries was the most common cause (76.92 %) for loss of tooth. Increase in residual ridge height ranged from (71.43 to 133.33 %) as measured by Denta-Scan. Implant survival rate was 100 %. Marginal bone loss ranged from 0.68 to 1.22 mm. Implant stability was measured by periotest (−2.7 to −3.6). Only one patient had perforation of sinus membrane, but it was sealed satisfactorily by bio-absorbable membrane.

Conclusion

One stage lateral sinus lift procedure with alloplastic bone graft material in combination with 2 stage implant placement has a predictable outcome in patients with severe resorption of posterior maxilla.     

Osteotome Maxillary Sinus Lift Using Bovine Bone and Calcium Sulfate: A Case Series

Purpose: The purpose of this longitudinal study was to evaluate the success of bovine bone and calcium sulfate (CaSO₄) as sinus augmentation material with osteotome maxillary sinus lift. Materials and Methods: Thirty‐one osteotome sinus lift procedures were performed for 18 healthy patients (7 males and 11 females). A mixture of bovine bone and CaSO₄ (ratio, 4:1) was used as sinus augmentation material with simultaneous implant placement. Implants were loaded 4 to 5 months postimplant surgery. Cases were followed for an average of 23.4 months postloading (range, 12–60 months). Results: The mean age of the study group was 49.7 ± 10.66 years. The residual height of the alveolar ridge ranged from 5.5 to 11 mm (mean, 8.16 ± 1.52 mm). Four to 5 months after implant placement, the x‐ray showed a 1.5 to 5 mm apical shift of the sinus floor (mean, 3.47 ± 0.97 mm), which was maintained to the end of the evaluation period. At 12 months postloading, crestal bone loss ranged from 0.5 to 1.5 mm (mean, 0.87 ± 0.26 mm), and pocket depth ranged from 2 to 4 mm (mean, 2.9 ± 0.67 mm). No significant change in crestal bone loss or pocket depth was noticed afterward. Conclusion: Bovine bone plus CaSO₄ can be used successfully as a sinus augmentation material with osteotome sinus elevation. The use of CaSO₄ significantly improved the handling properties of bovine bone and helped to stabilize the bone graft particles during healing.     

Sinus Lift Using a Nanocrystalline Hydroxyapatite Silica Gel in Severely Resorbed Maxillae: Histological Preliminary Study

Purpose: The aim of this preliminary study was to evaluate histologically a nanocrystalline hydroxyapatite silica gel in maxillary sinus floor grafting in severely resorbed maxillae.
Materials and Methods: A total of 16 consecutive patients scheduled for sinus lift were recruited during this study. Patients were randomly divided in two groups, eight patients each. In both groups, preoperative residual bone level ranged between 1 and 3 mm (mean value of 2.03 mm). No membrane was used to occlude the buccal window.
Second surgery was carried out after a healing period of 3 months in Group 1 and 6 months in Group 2. Using a trephine bur, one bone specimen was harvested from each augmented sinus and underwent histological and histomorphometric analysis.
Results: Histological analysis showed significant new bone formation and remodeling of the grafted material. In the cores obtained at 6 months, regenerated bone, residual NanoBone, and bone marrow occupied respectively 48 ± 4.63%, 28 ± 5.33%, and 24 ± 7.23% of the grafted volume. In the specimens taken 3 months after grafting, mean new bone was 8 ± 3.34%, mean NanoBone was 45 ± 5.10%, and mean bone marrow was 47 ± 6.81% of the bioptical volume.
Conclusions: Within the limits of this preliminary prospective study, it was concluded that grafting of maxillary sinus using nanostructured hydroxyapatite silica gel as only bone filler is a reliable procedure also in critical anatomic conditions and after early healing period.     

Influence of Sinus Floor Configuration on Grafted Bone Remodeling After Osteotome Sinus Floor Elevation

Background: This study investigates influence of the sinus floor configuration on dimensional stability of grafted bone height after the osteotome sinus grafting procedure. Methods: Forty single‐tooth dental implants inserted after placement of bioglass and/or allograft into the sinus area using an osteotome technique in 37 patients were evaluated in this retrospective study. Periapical radiographs were taken using the long‐cone technique before and after implant placement. Specifically, radiographic measurements of grafted bone height at the mesial and distal side of each implant were taken, and the sinus floor configuration was classified into concave, angle, and flat according to the sinus floor profile at the implant site. Furthermore, the intruding angle, defined as the angle between the implant axis and sinus floor, was measured. Results: All implants were clinically stable during a mean follow‐up period of 39.2 months. Mean initial gain of sinus grafted bone height was 7.0 ± 1.9 mm, and later it was reduced to 4.6 ± 1.9 mm at follow‐up (P <0.001). A greater reduction in grafted bone height was revealed in the flat sinus group compared with the concave group (P <0.001). Results from the linear regression showed larger intruding angles were statistically significantly associated with a greater reduction in grafted bone height (r² = 0.55, P <0.001). Conclusion: All bioglass and/or allograft placed in the maxillary sinus after the osteotome technique underwent remodeling and shrinkage; however, the outcome of the procedure was more predictable in sinuses with a concave floor and small implant‐intruding angles.     

超声骨刀在上颌窦内提升术中的应用

目的:探讨超声骨刀在上颌窦底内提升种植术中应用的效果和技术特点。方法:30名患者共36颗上颌磨牙缺失,牙槽嵴顶至上颌窦底之间的剩余骨高度2～8 mm,以超声骨刀行上颌窦底内提升术,同期或延期植入种植体。结果:24名患者植骨同时植入28枚种植体。6例因剩余牙槽骨高度少于5 mm先行上颌窦提升植骨术,6个月后延期植入8枚种植体。平均上颌窦底提升高度为426 mm(213～540 mm)。36个上颌窦提升位点,仅1例出现上颌窦黏膜穿孔,以Bio-Gide胶原膜修补。术后随访未发现种植体周围阴影或快速骨吸收。所有病例随访3～17个月,未见种植体脱落或松动现象。结论:超声骨刀上颌窦内提升术简单易学,避免了开窗式上颌窦提升术的术后反应,降低了上颌窦黏膜穿孔的机率,值得在临床上推广应用。