New Bone Formation in the Maxillary Sinus Without Bone Grafts

Maxillary sinus augmentation via the bone lid technique: A prospective, radiographic case series

BACKGROUND

Maxillary sinus augmentation is one of the most performed procedures to increase the bone quantity of the atrophic maxilla to allow implant placement. The aim of the present case series was to describe a surgical protocol to perform maxillary sinus augmentation with the "bone lid technique," and its outcomes in a cohort of patients eligible for the procedure.

METHODS

After the initial clinical evaluation, a cone-beam computed tomography (CBCT) examination was performed for preoperative assessment. Patients were then scheduled for surgical intervention. At 6-9 months follow-up, patients underwent a second CBCT scan to evaluate bone height following bone graft and to schedule implant placement.

RESULTS

A total of 11 patients were enrolled in the study with a total of 13 sinus lift procedures. Membrane perforation was registered in 4 cases (30.76%). Mean surgical time was 67.69 min (SD 6.51). Postoperative period was uneventful in all patients, in the absence of complications. The mean graft volume increase was 2.46 cm3 (SD 0.85), and the mean height increase was 14.27 mm (SD 3.18). Mean membrane thickness was 1.40 mm (SD 0.75). In all the 4 cases with sinus membrane perforation, the membrane had a thickness lower than 1 mm.

CONCLUSIONS

The present study highlights that the maxillary sinus augmentation with bone lid repositioning could provide repeatable results in terms of bone height increase. The technique appears reliable both in terms of bone gain and absence of complications.

KEY POINTS

The bone lid technique for maxillary sinus augmentation provides repeatable results in terms of bone height increase. The favorable clinical outcomes can be related to an enhancement of bone formation due to the unique osteoconductive and osteoinductive properties of autogenous bone, along with a reduction of soft tissue ingrowth. Complications were not observed in any of the patients following the surgical procedures. The risk of Schneiderian membrane perforation is inversely proportional to membrane thickness; the thinner the membrane is, the higher the risk to perforate it.

The Effect of Denatured Albumin with Concentrated Growth Factors in Minimally Invasive Sinus Piezosurgery: Preliminary Pilot Study Results

A new protocol with albumin-concentrated growth factor (CGF) is investigated through Piezosurgery as a minimally invasive alternative to sinus-floor-augmentation that is associated with high morbidity and high incidence of sinusitis. The clinical sample consists of five patients (three men and two women) with an average age of 53.75 ± 3.59 years and a mean height of 3.7 ± 1.22 mm of residual bone. The Piezo-Alb-CGF protocol consists of a minimally invasive transcrestal approach with or without flap, piezosurgery preparation, applying the Schneiderian membrane's hydrodynamic detachment-elevation, injecting albumin-CGF into the sinus, optional bone grafting and implantation, and evaluation for 2 to 6 months postoperatively. Eight implants were placed without complications. After 4 to 6 months, cone-beam computed tomography and panoramic radiographs showed total osseointegration and the formation of new bone. In addition, a year of clinical follow-up was performed. There was a positive correlation between implant stability quotient values at all protocol stages. The significance level was 5%. Albumin-CGF regenerative protocol promotes new bone formation, reduces postoperative morbidity, and shortens healing time. It also offers a uniform and safe hydraulic membrane lift and bicortical implant fixation, even in cases with a residual bone height below 6 mm.

Radiological Evaluation and Biomechanical Stability of Implants Simultaneously Placed at the Sites with Sole Advanced Platelet-Rich Fibrin (A-PRF) Grafted Sinus Floor

Introduction

In this retrospective study stabilities of 24 implants simultaneously placed at posterior maxillae with sinuses grafted by advanced platelet rich fibrin (A-PRF) and newly formed bone around them were evaluated.

Patient and Methods

Fourteen augmented maxillary sinuses of 11 patients with a mean residual alveolar bone height of 4.55 mm were involved in this study. Maxillary sinus lifting via lateral window approach and implant site osteotomy were performed, and prepared A-PRF clots were used as sole graft material. Each of the implants was immediately placed with a good primary stability. Postoperative sixth month tomography images were compared with preoperative ones in order to calculate the gained bone height and implant stability quotient (ISQ) values were recorded.

Results

The new vertical mean bone height of 24 implant sites was 12.21 mm with an implant survival rate of 100%. ISQ values of the implants were ranging from 62 to 75 with a mean value of 68. Statistically the diameter of implant did not have any effect on new bone formation and the ISQ values, however the length of them did.

Conclusion

A-PRF as a graft material for sinus lifting with simultaneous implant placement is a reliable technique with its low cost and lack of immunogenic reaction risk.

Assessment of absorbable gelatin sponge for maxillary sinus floor elevation versus anorganic bovine bone minerals: a randomized clinical trial

PURPOSE

The present study compared the absorbable gelatin sponge as a space-filling material versus anorganic bone bovine mineral (ABBM) in maxillary sinus augmentation with simultaneous endosseous dental implant placement.

METHODS

Eighteen maxillary sinus floor elevation cases were randomly allocated into two groups. The first group received ABBM, while the second group received an absorbable gelatin sponge as a space-filling material. For both groups, CBCT scans were obtained immediately postoperatively and six months later to calculate the difference in sinus floor bone gain. Osstell readings were recorded both at the time of implant placement and implant exposure with a total of twenty-three dental implant placements in relation to the eighteen elevated sinus floors.

RESULTS

The mean radiographic sinus floor gain in the ABBM group was 10.2 mm (± 2.5), while in the absorbable gelatin sponge group was 5.4 mm (± 2.0), with a mean difference of 4.8, which was statistically significant (p < 0.001). The mean implant stability for the ABBM was 77.3 (± 4.9), while in the absorbable gelatin sponge group was 74.2 (± 3.0), with a mean difference of 3.1, which was statistically insignificant (p = 0.1610).

CONCLUSION

The ABBM showed superior results regarding the amount of radiographic sinus floor bone gain. However, the implant stability was invariable between both groups.

Comparison between Platelet-rich Fibrin and Saline Filling after Sinus Elevation without Adjunctive Bone Graft in Dental Implants Insertion Using CBCT

AIM

The goal of this research was to compare radiographically the outcomes of hydraulic transcrestal sinus lifting with platelet-rich fibrin (PRF) or normal saline filling on implant survival rates, negative outcomes, and variations in the height of residual alveolar ridge (HARB).

MATERIALS AND METHODS

There were 80 study participants included and 90 dental implants were placed. The study participants were divided into two categories: Category A and Category B. Each category consists of 40 study participants. Category A: Normal saline was placed in the maxillary sinus. Category B: PRF was placed in the maxillary sinus. Implant survival, complications, and HARB alterations were the outcome metrics. Radiographic images through Cone-beam computed tomography (CBCT) were retrieved and compared prior to surgery (T0), immediately following surgery (T1), three months later (T2), 6 months later (T3), and 12 months later (T4).

RESULTS

There are 90 implants having an average length of 10.5 ± 0.7 mm were inserted into the posterior portion of the maxilla of 80 patients with an average HARB of 6.9 ± 1.2 mm. At T1, elevation in HARB peaked, and the sinus membrane continued to droop but steadied while observed at T3. The steady increment of areas of radiopacities was noticed below the elevated membrane of the maxillary antrum. A radiographic intrasinus bone increase of 2.9 ± 1.4 mm was caused by the PRF filling, compared to 1.8 ± 1.1 mm by the saline filling at T4 (p < 0.05). Over the course of the one-year follow-up period, all of the implants were operating normally with no major issues.

CONCLUSION

Platelet-rich fibrin when used as a filling medium alone without bone graft can cause significant ascend in height of the residual alveolar bone (HRAB).

CLINICAL SIGNIFICANCE

The degradation of the alveolar bone under the maxillary sinus following tooth loss frequently restricts the placement of the implant in the edentulous region of posterior maxilla. Numerous sinus-lifting surgery procedures and tools have been developed to address these problems. It has been a topic of debate regarding the benefits of bone grafts placed at the apical region of the implant. The sharp protrusions of the granules of bone graft may also provide a danger of membrane puncture. Recently, it was shown that regular bone gain might occur inside the maxillary antrum without the use of any bone transplant material. Additionally, if there were substances that filled the gap between the floor of the sinus and the raised sinus membrane, then the membrane of the maxillary sinus could be raised greater and for a longer period of time during the phase of formation of new bone formation.

The application of leukocyte- and platelet-rich fibrin (L-PRF) in maxillary sinus augmentation

BACKGROUND

Since the introduction of sinus augmentation in the 1970s the procedure has been performed with or without biomaterials. Autologous blood products (ABPs) for use in sinus augmentation was first introduced in the 2000s, to aid potentially in bone and soft tissue healing.

METHODS

Three different applications of leukocyte- and platelet-rich fibrin (L-PRF) in maxillary sinus augmentation are presented in this case series. In case 1, L-PRF is used in bilateral sinus augmentation to support placement of implants to support a maxillary hybrid denture. Case 2 highlights the use of L-PRF in a complication associate with Schneiderian membrane elevation. Case 3 provides histology taken at the time of implant placement 6 months following L-PRF/xenograft sinus augmentation.

RESULTS

All cases resulted in the successful placement of dental implants. In case 2, an osseodensification procedure was performed with freeze-dried bone allograft, which provided an approximate 4 mm of additional vertical height for implant placement. Histology from case 3 at 6 months post sinus augmentation demonstrated the presence of new vital bone in contact with the xenograft.

CONCLUSION

To date, there is only a limited amount of evidence reporting on platelet-rich fibrin (PRF) or L-PRF use in maxillary sinus augmentation. Bone gain from either product has ranged from 3.2 to 11.8 mm, with the percentage of newly formed bone reported in case series as 33% ± 5%. Despite the lack of strong evidence, L-PRF appears to have beneficial effects on bone regeneration when used in sinus augmentation.

The bone lid technique in lateral sinus lift: a systematic review and meta-analysis

Objective

This systematic review aimed at assessing the effect of the repositioned bone lid on bone augmentation in lateral sinus lift in pre-clinical in vivo and clinical studies. Secondary aims were to report on the healing of the bone window and to assess the implant survival rate.

Material and methods

Animal and human studies comparing lateral maxillary sinus floor elevation in combination or not with the repositioned bone lid were retrieved from MEDLINE (PubMed), Web of Science and Cochrane online library. Studies published in English up to April 2022 and reporting on histological and/or radiographic outcomes were considered. Case reports, case series and reviews were excluded. A hand search was also conducted. Risk of bias was assessed and meta-analysis performed to investigate the effect of the bone lid on new bone formation.

Results

After screening, 5 animal studies (4 in rabbits, 1 in sheep) and 2 clinical studies (1 RCT, 1 case–control) were included. Meta-analysis confirmed a higher new bone formation in rabbits at 2 and 8 weeks using the bone lid. The two clinical studies investigated lateral sinus lift with concomitant implant placement and reported similar results and high short-term implant success rate in both test and control groups.

Conclusions

The meta-analysis provided moderate evidence that the repositioned bone lid favored the formation of new bone to a higher extent as compared to resorbable membranes in animal studies. Implant success seems not to be influenced by the technique in the short term.

Effects of platelet-rich fibrin on osteogenic differentiation of Schneiderian membrane derived mesenchymal stem cells and bone formation in maxillary sinus

BACKGROUND

The existence of mesenchymal stem cells (MSCs) in Schneiderian membrane has not been determined. The aim of this study is to investigate whether there are MSCs in Schneiderian membrane, and the effect of platelet-rich fibrin (PRF) on osteogenic differentiation of these cells and on new bone formation in maxillary sinus after maxillary sinus floor elevation.

METHODS

Schneiderian membrane derived mesenchymal stem cells (SM-MSCs) were isolated from rabbit maxillary sinus. Cells were identified by flow cytometry and multipotential differentiation. Real-time cell analysis assay, fluorescence staining, transwell assay, and wound healing assay were used to determine the effects of PRF stimulation on cell proliferation and migration. The osteogenic differentiation ability of cells stimulated by PRF or osteoinductive medium was evaluated by alkaline phosphatase staining, alizarin red staining, PCR and Western blot. Equivalent volume Bio-oss and the mixture of Bio-oss and PRF were used as bone graft materials for maxillary sinus floor elevation. Micro-CT, bone double-staining, HE staining, Masson staining, and toluidine blue staining were used to evaluate the osteogenic effect in 8 and 12 weeks after surgery.

RESULTS

The cell surface markers were positive for expression of CD90, CD105, and negative for expression of CD34, CD45. SM-MSCs had the ability of osteogenic, adipogenic and chondrogenic differentiation. PRF could stimulate proliferation, migration and osteogenic differentiation of SM-MSCs, which was achieved by up-regulating ERK 1/2 signaling pathway. PRF could accelerate the formation of new bone in maxillary sinus and increase the amount of new bone formation.

CONCLUSIONS

MSCs existed in Schneiderian membrane, and PRF stimulation could promote cell proliferation, migration and osteogenic differentiation. The application of PRF in maxillary sinus floor elevation could accelerate bone healing and increase the quantity and quality of new bone. PRF, as autologous graft materials, might offer a promising strategy for the clinical bone formation during MSFE procedure. Video Abstract.

Implant Placement With Graftless Sinus Floor Elevation via the Lateral Approach: A Case Series With 4 Years Post-Loading Radiographical Outcomes and Implant Survival Rate

ABSTRACT

The purpose of the present study was to evaluate the radiographical outcomes, survival rate, and amount of bone formation around implants placed during graftless lateral sinus lift approach (GLSLA). Five patients (6 sinus augmentations) were consecutively treated with GLSLA. After Schneiderian membrane elevation and implant insertion, only blood clot was left to fill the new sinus compartment. After 4 months of healing, implants were functionally loaded. In all cases, samples were taken for biopsy at the time of second-stage surgery. The radiographical marginal bone variations and apical bone gain were assessed using cone beam-computed tomography taken 4 months after the surgery (at crown insertion) and after 4 years of loading. A total of 14 implants were placed in a mean initial residual bone height of 3.1 mm (range 1.6-4 mm). No failure was recorded, and all the implants were successfully loaded yielding a 100% survival rate. Vital bone formation was 33% according to the histomorphometry data. Four years after loading the mean radiographic bone remodeling was 1.3 mm. The mean ridge height was 7.6 mm and the mean apical bone gain amounted for 3.8 mm. Within the limitations of this study, the placement of dental implants in conjunction with GLSLA seems to be feasible and accompanied by high implant survival rate.

A New Approach for Lateral Sinus Floor Elevation

The lateral sinus lift procedure has been extensively investigated and described as a reliable surgical solution aimed at facilitating implant placement and rehabilitation when the posterior upper maxilla is atrophic. The standard technique consists in a lateral antrostomy, the careful raising of the sinus membrane, and following apposition of a bone substitute between the membrane and the sinus floor. The present technical note illustrates a new conservative technique enabling lateral sinus lift without the use of bone substitutes and with predictable outcomes.

The assessment of the effect of the size of lateral-antrostomy in graftless balloon elevation of the maxillary sinus membrane with simultaneous implant placement (a randomized controlled clinical trial)

BACKGROUND

The overlying maxillary sinus frequently restrains the height of the posterior maxillary bones.

PURPOSE

Evaluating the effect of downsizing the antrostomy side-window on the stability of the installed implants and vertical bone gain, after employing a graftless antral membrane balloon elevation (AMBE).

MATERIALS AND METHODS

The study is a randomized controlled clinical trial conducted on 20 patients with 30 deficient maxillary alveolar ridges underwent graftless (AMBE) after being allocated into a (5 mm) entry antrostomy group (the test group) and a (10 mm) entry antrostomy group (the control group) implementing a radiographic linear bone height and implant stability quotations (ISQ) comparison among both groups immediately after the placement of 38 Implants and 6 months after.

RESULTS

Radiographic bone gain of the test group (5.55 ± 0.93 mm) was significantly higher than the control group (2.86 ± 0.60 mm) (p <0.001). There was no significant difference in primary stability between the test (65 ± 5.32) and control groups (62.67 ± 4.46) (p = 0.202); while the test group (73.43 ± 4.39) showed significantly higher secondary stability than the control group (64.83 ± 6.05) (p <0.001). ISQ values recorded at 6 months were significantly higher than those recorded at insertion in the test group (p <0.001), while they were insignificant in the control group (p = 0.148).

CONCLUSION

Undersizing the antrostomy window deemed beneficial concerning the vertical bone gain and the simultaneously placed root form dental implants' secondary stability.

Implant placement with sinus floor elevation via the lateral approach using only absorbable collagen sponge: 12-month post-loading radiographical outcomes and implant survival rate

PURPOSE

The purpose of the present study was to evaluate the radiographical outcomes and survival rate of implants placed during graftless lateral sinus lift approach (GLSLA) using an absorbable collagen sponge.

MATERIALS AND METHODS

Fourteen patients (14 sinus augmentations) were consecutively treated with GLSLA. After Schneiderian membrane elevation and implant insertion, only collagen sponges were used to fill the new sinus compartment. After 4 months of healing, implants were functionally loaded. The radiographical marginal bone variation and apical bone gain were assessed on periapical radiographs taken 4 months after the surgery (at crown insertion) and at 12 months post-loading.

RESULTS

A total of 41 implants were placed in a mean initial residual bone height of 3.5 mm (range 1.6-6.7 mm). No failure was recorded and all the implants were successfully loaded with fixed prosthesis. Twelve months post-loading the mean radiographic bone remodeling was 2.22 mm. The mean ridge height was 8.4 mm and the mean apical bone gain amounted for 4.4 mm.

CONCLUSIONS

Within the limitations of this study, the placement of dental implants in conjunction with GLSLA using only a collagen sponge to fill the sinus compartment seems to be feasible and accompanied by a high implant survival rate. Further studies on a large population and with a longer follow-up are warranted to drawn definitive conclusions.

Tenting effect of dental implant on maxillary sinus lift without grafting

Background/purpose

Maxillary sinus lift without grafting is an alternative procedure that is used to lower the risk of infection and facilitate the surgical procedure. The objective of this study was to evaluate the tenting effect of the dental implant by measuring the amount and morphology of bone formation around it.

Material and methods

49 implants were placed in 26 patients by maxillary sinus lift without grafting. Radiographic images were taken preoperatively and at 6 months postoperatively and used to evaluate the height of the residual bone, the width of the maxillary sinus, the amount of bone formation, and the adjacent tooth.

Results

The most common type of bone formed around the implant, as seen in 23 cases, was the same height as the apex of the implant; in 11 cases, it was 0–2 mm above the apex of the implant, and in 7 cases, 2 mm or more. Meanwhile, 5 cases showed defects. The tent type of bone formation, which showed more bone formation at the implant apex than in the surrounding bone, was overwhelmingly the most common. (80.4%) The amount of bone formation increased in proportion to the difference between the residual bone height and the implant length. (P < .001).

Conclusion

The amount of bone formation in the sinus lift without grafting increased in proportion to the length of the implants in the maxillary sinus due to the tenting effect of the implant in the maxillary sinus membrane.

Radiologic comparative analysis between saline and platelet-rich fibrin filling after hydraulic transcrestal sinus lifting without adjunctive bone graft: A randomized controlled trial

OBJECTIVES

To evaluate implant survival rate, any complications, and changes in residual alveolar bone height (RABH) using saline or platelet-rich fibrin (PRF) filling after hydraulic transcrestal sinus lifting.

METHODS

Dental implants were placed after hydraulic transcrestal sinus lifting and the filling of saline (20 patients) or PRF (20 patients). Outcome measurements were implant survival, any complications, and RABH changes. Cone-beam computed tomography (CBCT) scans were taken and compared preoperatively (T0), immediately postoperatively (T1), at 3 months (T2), 6 months (T3), and 12 months postoperatively (T4), respectively.

RESULTS

In a total of 40 patients, 45 implants with a mean length of 10.4 ± 0.8 mm were placed in posterior maxilla of a mean RABH of 6.8 ± 1.1 mm. The increase in RABH peaked at T1, and continuous drooping of the sinus membrane was observed but stabilized at T3. Meanwhile, the gradual increase in the radiopacities was found below the lifted sinus membrane. The PRF filling induced the radiographic intrasinus bone gain of 2.6 ± 1.1 mm, which was significantly more than 1.7 ± 1.0 mm of saline filling at T4 (p < .05). All the implants were in function with no significant complications over the one-year follow-up period.

CONCLUSIONS

In this randomized case-control study, the feasibility of hydraulic transcrestal sinus lifting without bone graft was confirmed and PRF might be a better filler to support the elevated sinus membrane. However, adjunctive bone grafting should still be indicated for cases requiring more than 2-3 mm of intrasinus bone gain.

Clinical and Radiological Evaluation of Sinus Membrane Osteogenicity Subsequent to Internal Sinus Lifting and Implant Placement

To evaluate the ability of the maxillary sinus membrane to produce bone after internal sinus lifting and implant placement without adding exogenous bone graft, and to assess the quality of bone that has been produced 6 months postoperatively.In this retrospective study, 10 subjects who underwent maxillary sinus floor lifting and met the inclusion criteria were selected and then subdivided into: Group-A underwent internal sinus elevation and placement of implants without the use of bone graft and Group-B underwent classical internal sinus lifting and placement of bovine bone particles and then placement of the implant as a control group. Radiofrequency analysis (RFA) values for measuring the Implant Stability Quotient (ISQ) of all implants were measured by Osstell device. CBCT was performed involving linear measurements of the site of sinus lifting for both groups.High RFA values demonstrating excellent biomechanical stability were observed in Group-A compared to Group-B at 6 months postoperatively. Group-A showed a median of ISQ value;78 (8), 77(12), 79(3.5) and 77(4.50). Group-A was significantly higher in ISQ values than Group-B, which showed median and interquartile range (IQR) of ISQ value of [51(12.50), 54(14.50), 55(9), and 55(7.50)]. However, the amount of bone available in group B was significantly higher than group A; [3.5 mm (0.75) and 3.8 mm (0.69)].Internal sinus lifting without bone graft has the ability of bone formation by osteogenic potential of the sinus membrane. Nevertheless, the high quality of bone being produced is of high importance for the success of an implant without the need for an exogenous bone graft. The newly formed bone was significantly of a better quality in Group-A. Thus, it is recommended to perform internal sinus lifting, without adding bone graft material and allow the osteogenic potential of the maxillary sinus membrane to produce its own osteogenic cells.

The use of concentrated growth factor in dental implantology: A systematic review

In the era of evidence based dentistry, a well-documented consolidated data about improvements in dentistry is a necessity. Concentrated growth factor (CGF) is an emerging trend in periodontology and now in implant dentistry. Various studies have been published in the literature evaluating the effect of CGF on implant osseointegration, implant stability, survival rate, sinus augmentation, and peri-implant defects. However, no systematic review has yet been documented. The present systematic review, being first of its kind, aimed to evaluate the potential outcomes of employing CGF in implant treatment. A literature search was carried out in PubMed and Google scholar for articles published between 2001 and 2019, with various keywords such as "CGF," "dental implant," "bone regeneration," "CGF," and "osseointegration." The screening of studies was done according to PRISMA guidelines. A total of eleven studies were included in this review. Majority of the included studies pointed toward the beneficial effects of CGF in implant treatment. CGF was seen to promote osseointegration and enhance bone regeneration. Although more clinical studies are required to validate the potential merits of CGF in the long run, the preliminary results seem promising.

Maxillary sinus floor elevation using hydroxyapatite nano particles vs tenting technique with simultaneous implant placement: A randomized clinical trial

PURPOSE

The present study was conducted to evaluate the amount of bone height gain, density values, and implant stability after maxillary sinus floor elevation using graftless tenting technique or the use of Hydroxyapatite Nanoparticles bone substitute for augmentation with simultaneous implant placement.

MATERIALS AND METHODS

A total of 20 sinuses with a residual alveolar bone height ranging from 4-6 mm were divided into two groups and underwent sinus augmentation using nano hydroxyapatite bone substitute material and the graftless tenting technique with simultaneous implant placement. Computed tomography CT scans and ISQ measurements were conducted to evaluate bone quality, quantity, and implant stability.

RESULTS

Radiographic analysis revealed that the mean bone height gain of the nano group was (7.0 ± 0.8 mm) compared to (5.0 ± 1.5 mm) in the tent group, which was statistically significant (P = .002) being higher in the nano group. The mean bone density value of the nano group was (548 ± 25 HU) compared to (420 ± 23 HU) in the tent group, which was statistically significant (P < .001) being higher in the nano group. The mean ISQ value after 6 months in the nano group was (78 ± 5) compared to (77 ± 5) in the tent group, which was statistically nonsignificant (P = .901).

CONCLUSION

Nano hydroxyapatite bone graft offered superior results in terms of the bone height gain and the relative bone density as compared to graftless tenting technique. However, both techniques showed accepted results regarding implant stability.

Evaluation of New Bone Formation in Sinus Floor Augmentation With Injectable Platelet-Rich Fibrin-Soaked Collagen Plug: A Pilot Study

INTRODUCTION

The objective of this study is to evaluate the new bone formation after sinus floor augmentation with collagen plugs used as carriers for injectable platelet-rich fibrin (i-PRF).

MATERIALS AND METHODS

Postoperative immediate and postoperative 6th month panoramic radiographies of patients treated between January 1, 2015, and February 1, 2018, with sinus floor augmentation using i-PRF-soaked collagen plugs were retrieved from the archives, and subantral bone heights of distal and mesial regions of simultaneously inserted implants were measured with a software program. Statistical analysis was performed to understand whether there is a significant change in new bone formation at 6th month follow-up control.

RESULTS

A total of 18 implants were inserted in 12 patients. There was significant new bone formation at 6th month follow-up radiography at mesial and distal regions of inserted implants (P < 0.05).

CONCLUSION

New bone was regenerated with i-PRF carried by collagen plugs in sinus floor augmentation.

Clinical outcome and factors determining new bone formation in lateral sinus membrane elevation with simultaneous implant placement without grafting material: A cross-sectional, 3-17 year follow-up study

BACKGROUND

Lateral sinus membrane elevation with simultaneous implant placement without grafting material (graft-less LSFE) is a widely investigated method for bone augmentation of the maxillary sinus floor. Long-term follow-up studies are rare.

PURPOSE

This study aimed to investigate the long-term effects of implants placed with graft-less LSFE.

MATERIALS AND METHODS

The study group was comprised of 111 patients previously treated with graft-less LSFE. The first follow-up visit, which occurred after a mean of 5 years after surgery, included a clinical examination, cone beam computerized tomography, and panorama or intraoral radiography. The second follow-up included panorama or intraoral radiography, and it was conducted after a mean of 8 years.

RESULTS

Overall, 218 implants were placed in 127 sinuses. Nine of the 218 implants failed resulting in an overall implant survival of 95.9%. The average bone gain at the follow-up was 4.0 ±2.0 mm.

CONCLUSION

The implant-supported rehabilitation achieved using graft-less LSFE was stable over time, and there was no or little impact on sinus health. Furthermore, it was concluded that the new bone formation and the amount of bone gain is proportional to the length of the implant protruding into the sinus cavity.

Evaluation of Space-Maintaining Sinus Membrane Using the Absorbable Screws in Sinus Lifting Bone Augmentation

PURPOSE

We investigated whether it was possible to perform a sinus lift maintaining absorbable screw material with biological activity.

MATERIALS AND METHODS

Thirty rabbits were used. The screws used in this study were unsintered hydroxyapatite/poly-L-lactic acid (uHA/PLLA) (uHA/PLLA group) and titanium alloy (Ti group). Some uHA/PLLA screws were treated with ultraviolet light (UV-uHA/PLLA group). Each group consisted of 10 rabbits, and 2 screws were implanted for 1 rabbit. The screws were implanted into the frontal bone. Rabbits were euthanized at 3 days, 1, 2, 3, and 4 weeks postoperatively and prepared for histological examination, BMP-2 cell staining, and micro-computed tomography (micro-CT) assessment.

RESULTS

At 1, 2, and 3 weeks, the UV uHA/PLLA group had significantly more bone contact and new bone ratio on histological assessment than the other 2 groups. At 1, 2, 3, and 4 weeks, micro-CT assessment revealed significant differences between the UV uHA/PLLA group and the other 2 groups.

CONCLUSIONS

Sinus lift surgery using absorbable screw allowed bone formation. The UV-treated hydroxyapatite/poly-L-lactic acid (uHA/PLLA) was superior for sinus lift bone augmentation using a screw.

Blood clot stability and bone formation following maxillary sinus membrane elevation and space maintenance by means of immediate implant placement in humans. A computed tomography study

OBJECTIVE

The present controlled clinical pilot study proposed to assess blood clot contraction and bone neo-formation following maxillary sinus lift (MSL) with immediate implant placement without using grafts using cone beam tomography exams.

MATERIALS AND METHODS

Ten implants were placed in ten patients with a residual bone crest height ≥4 and ≤ 7 mm, in maxillary premolars or 1st or 2nd molars regions, using MSL and immediate implant placement without grafts, by means of the lateral window approach. A resorbable membrane (Bio-Gide®, Geistlich, USA) was used to close the window. Computed tomography images were taken after 15 (T1) and 180 (T2) days to assess the rate of blood clot contraction and bone neo-formation. The images were analysed by OsirixMD software. The Shapiro Wilk test was used to verify the normality hypothesis and the data were submitted to Student's paired t-test.

RESULTS

The mean of bone clot height in mesial, apical and distal area referred to implant, presented 4.77 mm, 0.77 mm and 5.30 mm respectively. The mean measurements of new bone formation presented 2.95 mm, 0.44 mm and 3.45 mm. The height contraction (coagulum/new bone formation), between T1 and T2, presented 38%, 43% and 35% respectively, with a significant statistical value p < 0.05. The volume measurements at T1 presented a mean volume of 0.90 cm³ sd ± 0.60 cm³ and at T2 a mean volume of 0.75 cm³ sd ± 0.62 cm³, with a significant volume contraction between T1 and T2, p < 0.005. The mean blood clot contraction was 16.52% ± 8.60%.

CONCLUSION

The present study demonstrates consistent bone formation around all assessed implants, although with significant contraction of the blood clot. The need for longitudinal studies to establish a long-term prognosis in different modalities of prosthetic rehabilitation of those implants is strongly suggested.

Sinus Floor Augmentation With Ambient Blood and an Absorbable Collagen Sponge: A Prospective Pilot Clinical Study

PURPOSE

The aim of this study was to clinically, radiologically, and histologically evaluate a sinus augmentation technique using a resorbable collagen sponge to maintain space between the Schneiderian membrane and the residual crestal bone.

MATERIALS AND METHODS

Patients with partially edentulous maxillae were clinically and radiographically evaluated for implant placement. A total of 10 consecutive patients with the bone height for implant placement (<4.0 mm) were enrolled in the study. The lateral maxillary wall was surgically exposed and the Schneiderian membrane was carefully elevated. A collagen wound dressing was placed in the antral area between the sinus floor and the raised membrane. The vertical sinus floor height was calculated using cone-beam computed tomography before the surgical procedure (baseline) and at 6 months postoperative. Immediately after the second scan, a core biopsy was removed for histological evaluation. The biopsy site was then further prepared for implant placement in the same location.

RESULTS

Biopsies showed mature cancellous bone with a predominantly lamellar structure. Well-vascularized intertrabecular spaces were filled with connective tissue and bone marrow. Analysis of bone height changes showed significant mean (SD) differences before and after procedures in anterior (2.67 ± 0.62 mm and 11.15 ± 1.1 mm), medial (2.98 ± 0.55 mm and 10.96 ± 0.77 mm), and posterior (3.17 ± 0.91 mm and 10.63 ± 0.51 mm) maxillary jaw locations (P = 0.005).

CONCLUSION

The collagen sponge provided an effective substrate for osseous regeneration of the sinus floor.

Maxillary Sinus Membrane Elevation With Simultaneous Installation of Implants Without the Use of a Graft Material: A Systematic Review

OBJECTIVE

To compare implant treatment outcome after maxillary sinus membrane elevation with simultaneous installation of implants with or without the use of graft material applying the lateral window technique.

MATERIALS AND METHODS

MEDLINE/PubMed, Cochrane Library, and Embase search in combination with a hand-search of relevant journals was conducted from January 1, 2004 to January 1, 2016.

RESULTS

Thirteen studies fulfilled the inclusion criteria. Survival of suprastructures has not been compared within the same study. Short-term implant survival without graft material varied between 96% and 100% compared to 100% for autogenous bone or bone substitutes. No significant difference in bone gain was reported without graft material compared to autogenous bone. The density of newly formed bone increased significantly during the observation period. Bone density was significantly higher in sinuses augmented with blood clot compared to bone substitute, whereas no significant difference was found when compared to autogenous bone. Noncomparative studies demonstrated high long-term implant survival and new bone formation after sinus membrane elevation without graft material.

CONCLUSIONS

Sinus membrane elevation without the use of a graft material seems to enhance new bone formation with high implant survival, but long-term comparative studies are missing.

Sinus floor elevation procedures to enable implant placement and integration: techniques, biological aspects and clinical outcomes

Implant treatment in an atrophied edentulous posterior maxilla constitutes a challenge for the therapeutic team. The authors of the present study acknowledge that modern micro-rough surface implants in lengths of about 8-10 mm or longer and of different brands are similarly successful. Consequently, the authors propose that the use of different sinus floor elevation techniques should be considered when < 8 mm of bone is available below the maxillary sinus. The type of sinus floor elevation technique selected is mainly based on residual vertical bone height, marginal bone width, local intrasinus anatomy and the number of teeth to be replaced, although other factors (such as surgical training and surgical experience) may have an impact. It is proposed that a transcrestal sinus floor elevation approach can be considered as a first-choice method for single tooth gaps in situations with sufficient width for implant placement and a residual bone height of 5-8 mm, while lateral sinus floor elevation, with or without grafting materials, is indicated when < 5 mm of bone is available and when several teeth are to be replaced. With regard to time of implant placement, a one-stage procedure is preferred provided that high primary stability can be ensured.

Guided maxillary sinus floor elevation using deproteinized bovine bone versus graftless Schneiderian membrane elevation with simultaneous implant placement: Randomized clinical trial

OBJECTIVE

The aim of this study is to evaluate the analytical difference between the use of xenograft (control group) and graftless tenting (test group) technique after sinus lift procedure with simultaneous implant placement.

MATERIALS AND METHODS

Seventeen patients and 20 sinuses where operated for sinus lift procedures using lateral window approach with simultaneous implant placement. Deproteinized bovine bone (Xenograft) was used as a filling material in control group while nongrafted sinus lifting was performed in the test group. Multislice CT was obtained preoperatively and CBCT were obtained immediately postoperative and 6 months after operation. Osstell readings were taken at the time of implant placement and implant exposure (6 months) RESULTS: Mean bone height gain in the xenograft group was 8.59 ± 0.74 while that of the tenting group was 4.85 ± 0.5 and it was statistically significant (P < .05). Mean bone density values in the xenograft group was 375.59 ± 49.38 while that of the tenting group was 269.08 ± 16.27 and it was statistically significant (P < .05). Mean ISQ values for the xenograft group was 78.3 ± 5.08 while that of the tenting group was 74 ± 3.19 and it was statistically significant (P < .05).

CONCLUSIONS

Within the limitation of this study, sinus lift procedures with simultaneous implant placement using xenograft as a filling material or graftless technique are considered reliable procedures, however, the use of xenograft provide better results in all aspects regarding (bone height gain, bone density, and implant stability).

A prospective randomized controlled trial of the two-window technique without membrane versus the solo-window technique with membrane over the osteotomy window for maxillary sinus augmentation

BACKGROUND

Maturation of the grafted volume after lateral sinus elevation is crucial for the long-term survival of dental implants.

PURPOSE

To compare endo-sinus histomorphometric bone formation between the solo- and two-window maxillary sinus augmentation techniques with or without membrane coverage for the rehabilitation of multiple missing posterior teeth.

MATERIALS AND METHODS

Patients with severely atrophic posterior maxillae were randomized to receive lateral sinus floor elevation via the solo-window technique with membrane coverage (Control Group) or the two-window technique without coverage (Test Group). Six months after surgery, bone core specimens harvested from the lateral aspect were histomorphometrically analyzed.

RESULTS

Ten patients in each group underwent 21 maxillary sinus augmentations. Histomorphometric analysis revealed mean newly formed bone values of 26.08 ± 16.23% and 27.14 ± 18.11%, mean connective tissue values of 59.34 ± 12.42% and 50.03 ± 17.13%, and mean residual graft material values of 14.6 ± 14.56% and 22.78 ± 10.83% in the Test and Control Groups, respectively, with no significant differences.

CONCLUSIONS

The two-window technique obtained comparative maturation of the grafted volume even without membrane coverage, and is a viable alternative for the rehabilitation of severely atrophic posterior maxillae with multiple missing posterior teeth.

Maxillary Sinus Floor Augmentation: a Review of Selected Treatment Modalities

Objectives

The objective of the present study is to present the current best evidence for enhancement of the vertical alveolar bone height and oral rehabilitation of the atrophic posterior maxilla with dental implants and propose some evidence-based treatment guidelines.

Material and Methods

A comprehensive review of the English literature including MEDLINE (PubMed), Embase and Cochrane Library search was conducted assessing the final implant treatment outcome after oral rehabilitation of the atrophic posterior maxilla with dental implants. No year of publication restriction was applied. The clinical, radiological and histomorphometric outcome as well as complications are presented after maxillary sinus floor augmentation applying the lateral window technique with a graft material, maxillary sinus membrane elevation without a graft material and osteotome-mediated sinus floor elevation with or without the use of a graft material.

Results

High implant survival rate and new bone formation was reported with the three treatment modalities. Perforation of the Schneiderian membrane was the most common complication, but the final implant treatment outcome was not influenced by a Schneiderian membrane perforation.

Conclusions

The different surgical techniques for enhancement of the vertical alveolar bone height in the posterior part of the maxilla revealed high implant survival with a low incidence of complications. However, the indication for the various surgical techniques is not strictly equivalent and the treatment choice should be based on a careful evaluation of the individual case. Moreover, further high evidence-based and well reported long-term studies are needed before one treatment modality might be considered superior to another.

Graft-Free Maxillary Sinus Floor Elevation: A Systematic Review and Meta-Analysis

BACKGROUND

This systematic review and meta-analysis aims to investigate survival rates of dental implants placed simultaneously with graft-free maxillary sinus floor elevation (GFSFE). Factors influencing amount of vertical bone gain (VBG), protruded implant length (PIL) in sinus at follow-up (PILf), and peri-implant marginal bone loss (MBL) are also evaluated.

METHODS

Electronic and manual searches for human clinical studies on simultaneous implant placement and GFSFE using the lateral window or transcrestal approach, published in the English language from January 1976 to March 2016, were conducted. The random-effects model and mixed-effect meta-regression were used to analyze weighted mean values of clinical parameters and evaluate factors that influenced amount of VBG.

RESULTS

Of 740 studies, 22 clinical studies were included in this systematic review. A total of 864 implants were placed simultaneously with GFSFE at edentulous sites having mean residual bone height of 5.7 ± 1.7 mm. Mean implant survival rate (ISR) was 97.9% ± 0.02% (range: 93.5% to 100%). Weighted mean MBL was 0.91 ± 0.11 mm, and it was significantly associated with the postoperative follow-up period (r = 0.02; R2 = 43.75%). Weighted mean VBG was 3.8 ± 0.34 mm, and this parameter was affected significantly by surgical approach, implant length, and PIL immediately after surgery (PILi) (r = 2.82, 0.57, 0.80; R2 = 19.10%, 39.27%, 83.92%, respectively). Weighted mean PILf was 1.26 ± 0.33 mm (range: 0.3 to 2.1 mm).

CONCLUSION

Within limitations of the present systematic review, GFSFE with simultaneous implant placement can achieve satisfactory mean ISR of 97.9% ± 0.02%.

Three-Year Clinical and Radiographic Implant Follow-up in Sinus-Lifted Maxilla With Lateral Window Technique

INTRODUCTION

The aim of this study was to evaluate retrospectively the 3-year outcome of implants placed in augmented maxillary sinuses with minimal residual alveolar bone heights (≤3 mm).

MATERIALS AND METHOD

A total of 28 sinus floors were augmented with xenograft, and 58 implants were placed. The outcome measures were implant success based on implant stability and the absence of periimplantitis, and marginal and apical bone resorption on periapical radiograph and prosthesis survival.

RESULTS

Fifty-seven of 58 implants with their prostheses remained functional with a success rate of 98.28%. None of the implants showed any signs of mobility or periimplantitis. Both apical and cervical bone resorption around the implants were highest by the end of the first year.

CONCLUSIONS

The success rate of the implants placed with staged approach in augmented maxillary sinuses with the residual alveolar bone height of ≤3 mm was high in a 3-year term. Bio-Oss is an acceptable substitute autogenous bone and can be used as an augmentation material during the maxillary sinus lift procedure.

Maxillary sinus floor elevation with simultaneous implant placement without grafting materials: a systematic review and meta-analysis

The present study aimed to conduct a systematic review and meta-analysis on the effectiveness of maxillary sinus floor elevation and immediate implant installation without the use of grafting material. An electronic search without date or language restriction ​​was performed in PubMed/MEDLINE, Cochrane Central Register of Controlled Trials, Web of Science, Embase, and the grey literature, to May 2016. Eligibility criteria encompassed prospective and retrospective cohort studies, controlled clinical trials, and randomized clinical trials. The search and selection process yielded 18 studies, published between 2005 and 2016. A meta-analysis was conducted only for experimental studies comparing sinus floor elevation with and without grafting material; results were expressed as the standardized mean difference (SMD) or risk ratio (RR) with the 95% confidence interval (CI). An average gain in bone height of 4.7mm over an average 39.4 month period was observed in the sinus elevated without grafting material. Regarding implants, there was a cumulative average survival rate of 97%. On meta-analysis, bone gain (P=0.98) and implant survival (P=0.13) did not differ significantly between sinuses lifted with or without grafting material, with a SMD of 0.01 (95% CI -0.42 to 0.44) and with a RR of 0.55 (95% CI 0.26 to 1.19), respectively.

Space-maintaining management in maxillary sinus lifting: a novel technique using a resorbable polymeric thermo-reversible gel

Several techniques have been proposed to achieve sinus floor elevation and the formation of new bone through the grafting of autologous, heterologous, or alloplastic materials. The grafted materials act as a scaffold for bone formation inside the maxillary sinus. This study investigated a non-graft sinus lifting procedure using a resorbable polymeric thermo-reversible gel. A space-maintaining approach to sinus lifting, using a resorbable polymeric thermo-reversible gel, was applied in 11 patients undergoing implant treatment in the atrophic posterior maxilla. After a healing period of 6 months, a total of 14 implants were placed; biopsies were taken and evaluated histologically and histomorphometrically. The parameters evaluated included the percentages of new bone formation, residual gel, and fibrous tissue. Histological examination showed the formation of new bone with no fibrous tissue or severe inflammatory cellular infiltration. The percentage of newly formed bone was in the range of 54-60%; this consisted of both lamellar and woven bone. No foreign-body reaction was observed. The mean quantities of both residual gel and connective tissue were small. This non-graft sinus lifting procedure using a space-maintaining gel appears to stimulate predictable bone formation; it is thus a useful technique for promoting bone formation in the sinus.

Maxillary sinus lift surgery-with or without graft material? A systematic review

The purpose of this systematic review was to perform a comparative analysis of the use or not of graft material in maxillary sinus lift surgery. Relevant studies published in the last 10 years were identified through a search of the PubMed/MEDLINE, ScienceDirect, and Cochrane Library databases and were assessed against the study inclusion and exclusion criteria. The initial search resulted in 1037 articles. After applying the inclusion and exclusion criteria, 16 articles remained. Four hundred and thirty-six patients were followed up over a postoperative period ranging from 6 months to 11 years. In total, 868 implants were installed in 397 maxillary sinuses. The implant survival rate was 96.00% for surgeries performed without graft material and 99.60% for those in which biomaterial was used, within a follow-up period of 48 to 60 months. In conclusion, maxillary sinus lift surgery, with or without graft material, is a safe procedure with a low complication rate and predictable results.

Graftless sinus augmentation with simultaneous dental implant placement: clinical results and biological perspectives

After a sinus lifting procedure, the compartment around the implants under the sinus mucosal lining in the sinus floor is filled with a blood clot from surrounding bleeding. The aim of this study was to evaluate the feasibility of bone formation following graftless sinus lifting with the simultaneous placement of dental implants. Thirty graftless sinus lifting procedures were performed and 72 dental implants placed in 18 consecutive patients, using the lateral window approach. Clinical and radiological follow-up was conducted throughout the 6-month healing period. Biopsies of 30 cases were collected at 6 months post-treatment: 15 biopsies were taken from the newly formed bone near the basal floor and 15 from the newly formed bone near the elevated membrane. New bone consolidation in the maxillary sinus was apparent radiologically and histologically at 6 months after sinus augmentation, providing an average 6.14±1.34mm of bone-gain. Based on histological analysis and histomorphometric data, the consolidated bone in the augmented sinus comprised 56.7±11.9% to 59.9±13.4% vital bone tissue. Out of the 72 implants placed, only four failed, indicating a 94% overall implant survival rate. Based on this case series, blood clot can be considered autologous osteogenic graft material, to which osteoprogenitors can migrate, differentiate, and regenerate bone.

Flapless transcrestal sinus augmentation using hydrodynamic piezoelectric internal sinus elevation with autologous concentrated growth factors alone

PURPOSE

The purpose of this retrospective study was to evaluate the success rate of implants and the amount of sinus augmentation using the flapless hydrodynamic piezoelectric internal sinus elevation (HPISE) technique with autologous concentrated growth factors (CGF) alone.

MATERIALS AND METHODS

A total of 11 maxillary sinuses were augmented using the HPISE technique through the flapless transcrestal approach. Sixteen implants (average 11.38 mm in length and 4.83 mm in diameter), with 2 different surfaces, were placed simultaneously with CGF alone. Plain panoramic radiograms and cone-beam computed tomograms (CBCT) were taken in all patients to evaluate the sinus augmentation preoperatively and postoperatively.

RESULTS

The sinus membranes were successfully elevated, averaging 13.95 ± 6.61 mm in immediate postoperative CBCT without any iatrogenic perforation. After an average 23.8 weeks, the average bone gain above the sinus floor was 8.23 ± 2.88 mm in the axial aspect of CBCT. No complications were recorded in any patients during the follow-up period.

CONCLUSION

The flapless transcrestal approach to the sinus augmentation using the HPISE technique with autologous CGF alone could be an alternative to the lateral approach, even at severely resorbed edentulous posterior maxilla with insufficient bone height.

Long-term outcome of dental implants after maxillary augmentation with and without bone grafting

Background

This study aims to evaluate the technique of sinus bone reformation, which consists of elevating the sinus membrane and placement the implant without bone graft, compared with the widely-used technique involving raising the maxillary sinus and grafting, using animal hydroxyapatite as the filler, while simultaneously fixing the implants.

Material and Methods

This is a retrospective study on two groups of patients who underwent elevation of the sinus membrane and simultaneous placement of the implant. The grafting technique was applied to one group, while the other had no graft. An alveolar ridge height of 4 to 7 mm was necessary. Radiological control was undertaken at 6 months and one year post-prosthetic loading. In each group 38 implants were placed.

Results

No significant behavioural differences were observed in the implants according to the Albrektsson success criteria. Implant failure was observed in 2 implants from the bone grafting group (success rate 93%) and in 1 implant from the reformation group (success rate 97%). In this group, bone formation was observed on both sides of each implant, the bone gain was measured using image management software (2.7±0.9mm mesial and 2.6±0.9mm distal). There was no correlation between mesial and distal bone gain and implant´s length.

Conclusions

The results indicate that bone reformation is a valid technique in cases involving atrophy of the posterior maxilla. Primary stability, maintenance of space by the implant, and the formation of a blood clot are crucial in this technique in order to achieve bone formation around the implant. It is an alternative to the conventional technique of sinus lift with filling material, and has several advantages over this procedure, including a lower infection risk, as it does not involve a biomaterial, reduced cost, a simpler technique, and better acceptance by the patient.

Key words:Bone formation, sinus membrane elevation, maxillary sinus, bone grafting.

Maxillary sinus augmentation using sinus membrane elevation without grafts - A Systematic Review

Implants have a predictable outcome and are the foremost treatment modality for prosthetic rehabilitation of edentulous patients. Due to loss of bone after extraction and pneumatization of maxillary sinus, there is insufficient bone volume for implant placement. The direct maxillary sinus lift procedure has been performed with different grafting materials (autogenous bone grafts, alloplasts, allografts, and xenografts) and without grafting material, having new bone formation around the implant. There is no evidence to prove the need for grafting material in all direct sinus lift procedures, hence the need for this review. Previous meta-analysis showed that survival rates of implants placed in grafted maxillary sinuses had similar survival rates whether autogenous, allogenous, or alloplastic grafts were used. This paper aims to review scientific data on the direct sinus elevation technique without use of any grafting material, volume of new bone formed, and also mechanism behind this technique. Articles were searched from 1997 to October 2014 in PubMed, Google Scholar, and Cochrane CENTRAL. The study eligibility criteria were (1) direct sinus lift procedure without any graft material during implant placement and (2) human or animal studies with a minimum follow-up of 6 months or more. Two authors independently scrutinized the literature and if any controversy was raised, third author's opinion was sought to arrive at a mutual consensus for including the study in the review. Due to the heterogeneity across all studies in all study designs, the data were not pooled and a meta-analysis was not performed. Taking into consideration all factors reviewed in this regard along with the outcomes, the direct sinus lift technique without grafting can be suggested as a viable treatment option keeping in mind the limitations involved. The average bone gain was seen across all studies ranging from 2.37 to 10 mm and with an implant survival rate ranging from 79.9% to 100% across studies.

Comparative histomorphometric analysis of maxillary sinus augmentation with absorbable collagen membrane and osteoinductive replaceable bony window in rabbits

PURPOSE

The aim of this animal study was to evaluate, through histomorphometric evaluation, bone regeneration in rabbit maxillary sinuses with absorbable collagen membranes and osteoinductive replaceable bony windows over bone grafts.

MATERIALS AND METHODS

Bilateral sinus augmentation procedures were performed in 16 adult male rabbits. The rabbits were randomly assigned to 4 groups of 4 rabbits each. Rectangular replaceable bony windows were made with a piezoelectric thin saw insert. In control group, grafted β-tricalcium phosphate (β-TCP) was covered by absorbable collagen membranes. In experimental groups, β-TCP was grafted and covered by replaceable bony windows. The rabbits were killed at 1, 2, 4, and 8 weeks postoperatively. The augmented sinuses were stained with hematoxylin-eosin and Masson trichrome stains and examined, under light microscopy, for newly formed bone and soft tissue changes in the maxillary sinuses.

RESULTS

Histologically, significantly higher and faster new bone formation was observed in the augmented sinuses of the experimental groups, receiving homologous replaceable bony windows than in those of the control group receiving collagen membranes.

CONCLUSION

This study demonstrates that, for augmentation, the use of the homologous replaceable bony window over bone graft material on the maxillary sinus accelerates bone regeneration.

Management of a Large Schneiderian Membrane Perforation and Repair of the Missing Maxillary Lateral Wall Using a Collagen Barrier Alone in a Patient With Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome

INTRODUCTION

Sinus floor augmentation (SFA) to aid in implant placement has been shown to be very predictable. A history of membrane perforation or intraoperative Schneiderian membrane perforation (SMP) is one of the most frequent complications of SFA. In this case report, the management of a large preexisting SMP with the aid of a collagen barrier in a patient with human immunodeficiency virus/acquired immunodeficiency syndrome is described.

CASE PRESENTATION

A 51-year-old male presented for retreatment of an endodontically treated maxillary molar (tooth #14). The endodontic consultation recommended extraction, which was performed by the patient's primary dentist. Two months later, a clinical and radiographic examination revealed significant vertical and bucco-lingual bone loss in that area. Cone-beam computed tomography (CBCT) indicated insufficient bone volume for implant placement and the absence of cortical bone with a homogeneous fibrous mass in the edentulous region. A lack of Schneiderian membrane continuity, most likely the result of the extraction, was suspected. A treatment plan of guided bone regeneration followed by implant placement was presented. The SMP was repaired using a collagen barrier alone, and postoperative healing was uneventful. One year later, a repeat CBCT scan revealed complete reformation of the buccal cortical plate and sinus floor with ≈6 mm of vertical bone gain. An implant was placed without complications 16 months after SMP repair.

CONCLUSIONS

This case report describes how a large preexisting SMP was repaired using a collagen barrier alone. Three-dimensional bone regeneration was achieved without the use of bone grafts primarily because of the stability of the blood clot.

Lateral Bone Window Closing Technique with Poly-L-Lactic Acid (PLLA) Membrane in the Augmentation of the Maxillary Sinus without Grafting Material: Evaluation of Bone Healing in a Rabbit Model

BACKGROUND

When augmenting the maxillary sinus without grafting material, the method used to cover the bony window is a subject of debate.

PURPOSE

The purpose of this study was to evaluate the poly-L-lactic acid (PLLA) membrane as closing material of the lateral window in a maxillary sinus augmentation without bone grafting.

MATERIALS AND METHODS

Augmentation of the maxillary sinus without grafting material and installation of titanium screws that fix the Schneiderian membrane were performed in 18 Japanese male white rabbits. The bony window was covered with a collagen membrane or PLLA membrane or no membrane. The animals were sacrificed at 4 or 8 weeks. New bone volume was calculated radiologically using microcomputed tomography (micro-CT). The samples were analyzed histologically after toluidine blue staining.

RESULTS

No significant differences were observed in the new bone volume, as measured by micro-CT. However, histomorphometric analysis demonstrated the superiority of the PLLA membrane in new bone formation compared with the collagen membrane.

CONCLUSION

The PLLA membrane is a suitable material to be applied for tissue regeneration in this animal model.

The Study of the Effect of Concentrated Growth Factors (CGF) on the New Bone Regeneration of Immediate Implant

Objective: To study the effect of concentrated growth factor (CGF) on reducing bone resorption in immediate implant. Methods: 20 immediate implant patients were divided into two groups, each group included 10 patients who were treated by adding CGF or Bio-oss to the gap of implant-bone, respectively; the labial new bone regeneration was evaluated in postoperative 1 years using cone beam CT. Results: The buccal bone width variation of the CGF group was 0.85±0.25mm, and the Bio-oss group was 0.35±0.25mm (p <0.05). Conclusion: The CGF has no significant role in promoting new bone regeneration when was used alone in the gap of implant - bone in immediate implant

Effect of maxillary sinus floor augmentation without bone grafts

Objective:

The objective of the present review was to determine the effectiveness of maxillary sinus floor augmentation without bone grafts using lateral window technique.

Materials and Methods:

PubMed and Cochrane databases were searched for relevant articles. We also included articles by hand search until June 2012. The analysis included both human and animal studies which satisfied the following criteria: Minimum of 6 months follow-up, no use of bone grafts, and lateral window approach to the sinus.

Results:

We included 22 articles in the review. A descriptive analysis of the constructed evidence tables indicated that there is evidence of predictable a mount of bone formation in the maxillary sinus augmentation without the use of bone grafts.

Conclusion:

Within the limits of the articles and data available, maxillary sinus augmentation without bone graft might be considered effective inpredictable bone formation.

Interventions for replacing missing teeth: augmentation procedures of the maxillary sinus

BACKGROUND

Insufficient bone volume is a common problem encountered in the rehabilitation of the edentulous posterior maxillae with implant-supported prostheses. Bone volume is limited by the presence of the maxillary sinus together with loss of alveolar bone height. Sinus lift procedures increase bone volume by augmenting the sinus cavity with autogenous bone or commercially available biomaterials, or both. This is an update of a Cochrane review first published in 2010.

OBJECTIVES

To assess the beneficial or harmful effects of bone augmentation compared to no augmentation when undertaking a sinus lift procedure. Secondly, to compare the benefits and harms of different maxillary sinus lift techniques for dental implant rehabilitation.

SEARCH METHODS

We searched the Cochrane Oral Health Group's Trials Register (to 17 January 2014), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2013, Issue 12), MEDLINE via OVID (1946 to 17 January 2014) and EMBASE via OVID (1980 to 17 January 2014). There were no language or date restrictions on the searches of the electronic databases.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of different techniques and materials for augmenting the maxillary sinus for rehabilitation with dental implants that report the outcome of implant success or failure at least to four months after initial loading.

DATA COLLECTION AND ANALYSIS

Screening of eligible studies, assessment of the risk of bias of the trials, and data extraction were conducted independently and in duplicate. Authors were contacted for any missing information. Results were expressed using fixed-effect models as there were either less than four studies or we used Peto odds ratios (ORs) for dichotomous data when there were zero cells in either the treatment or control or both arms and the number of trials was small. The statistical unit of the analysis was the patient.

MAIN RESULTS

Eighteen RCTs out of 64 potentially eligible study reports met the inclusion criteria. They compared undertaking a sinus lift with not doing so, and the use of different sinus lift techniques. There were 650 patients providing data for the outcomes evaluated. Five studies were assessed as low risk of bias, 11 were assessed as high risk of bias, and in two the risk was unclear. Sinus lift versus no sinus lift Four trials of moderate quality (three trials at low and one at high risk of bias) with 102 participants evaluated short implants (5 to 8.5 mm long) as an alternative to sinus lift in bone with residual height between 4 and 9 mm. One year after loading there was insufficient evidence to claim differences between the two procedures for prosthesis failure (OR (Peto) 0.37, 95% confidence interval (CI) 0.05 to 2.68; three trials) or implant failure (OR (Peto) 0.44, 95% CI 0.10 to 1.99; four trials). There was however an increase in complications at treated sites when undertaking the sinus lift (OR (Peto) 4.77, 95% CI 1.79 to 12.71, P value = 0.002; four trials). Different sinus lift techniques Fourteen trials with 548 participants compared different sinus lift techniques. Only three comparisons included more than one trial (two trials for each). These were bone graft versus no bone graft, autogenous bone versus bone substitute, bone graft with or without platelet-rich plasma (PRP). There was insufficient evidence to claim a benefit for any of these techniques for the primary outcomes of prosthesis and implant failure. For the other reported outcomes, in a single study at high risk of bias, only bone gain was greater for the bone graft site than the site without a graft six months after augmentation, however this was not significant at 18 or 30 months.The other comparisons with single studies were rotary versus piezosurgery to open a lateral sinus window, two different bone substitutes, use or not of a membrane to seal the lateral window, one- versus two-stage lateral sinus lift, two-stage granular bone versus one-stage autogenous bone blocks, and crestal versus lateral sinus lift; two trials compared three different crestal sinus lifting techniques: rotatory versus hand malleting (patients preferred rotatory instruments over hand malleting) and hand versus electric malleting. There was no evidence of a benefit for any sinus lift procedure compared to any other for the primary outcomes prosthesis or implant failure.

AUTHORS' CONCLUSIONS

There is moderate quality evidence which is insufficient to determine whether sinus lift procedures in bone with residual height between 4 and 9 mm are more or less successful than placing short implants (5 to 8.5 mm) in reducing prosthesis or implant failure up to one year after loading. However, there are more complications at sites treated with sinus lift procedures. Many trials compared different sinus lift procedures and none of these indicated that one procedure reduced prosthetic or implant failures when compared to the other. Based on low quality evidence, patients may prefer rotary instruments over hand malleting for crestal sinus lift.

Implant success remains high despite grafting voids in the maxillary sinus

OBJECTIVES

Given that the nature and presence of voids present within grafted sinuses following maxillary sinus elevation procedures were not known, nor was the contribution of these factors to implant success, the purpose of this study was to investigate these parameters and their relationship to implant success.

MATERIALS AND METHODS

This study evaluated data from 25 subjects who had a lateral window maxillary sinus augmentation procedure. Cone-beam computed tomography (CBCT) was performed at baseline and 4 months after surgery. CBCT images were used to evaluate grafted sites prior to implant placement. Using CBCT images, three examiners independently measured bone-grafted areas (BG), void areas (V), and percentage of void areas (V%) from six different sections within grafted sites. The six sections were defined as a cross-sectional (CS) midpoint, CS mesial point, CS distal point, horizontal section (HS) low point, HS midpoint, and HS high point. Implant success was also determined.

RESULTS

The calculated V% (V/BG) for the CS midpoint, CS mesial point, CS distal point, HS low point, HS midpoint, and HS high point were 5.30 ± 6.67%, 5.79 ± 8.51%, 6.67 ± 7.12%, 2.07 ± 2.56%, 5.30 ± 6.62%, and 4.92 ± 5.17% respectively. Implant success after 6 months of follow-up approximated 100%.

CONCLUSIONS

Although voids within grafts varied in terms of distribution and size, the V% within the HS low point were significantly smaller compared to those within the CS midpoint and CS distal point, which had the most intra-subject V%. Thus, more attention should be given to the distal aspect of the sinus when compacting graft materials in the lateral wall sinus augmentation procedure. Implant success was not influenced by the existence of voids as implant success remained high.