A new sinus lift technique in conjunction with placement of 265 implants: a 6-year retrospective study

Mini Crestal Sinus Lift With Bone Grafting and Simultaneous Insertion of Implants in Severe Maxillary Conditions as an Alternative to Lateral Sinus Lift: Multicase Study Report of Different Techniques

The present study evaluates the efficacy and clinical outcomes of crestal sinus lift techniques used to elevate the sinus floor simultaneously with bone grafting and implant placement as a possible and reproducible alternative to lateral sinus lift. Patients underwent different crestal sinus elevation techniques. The heterologous biomaterial was used as graft material, and multiple implants were placed simultaneously after sinus augmentation. Radiographic and clinical examinations were performed during follow-up. All procedures were successfully performed without any apparent perforation of the Schneider membrane. The sinus floor was augmented with an average height of 5 mm (range: 2.8-7.4 mm). The implants healed smoothly with healing screws. Peri-implant marginal bone was stable with a mean follow-up of 50 months (range: 33-71 mo). No complications were observed during the follow-up. Based on the limited data collected in this study, the new crestal sinus elevation approach can effectively raise the sinus floor and reduce the incidence of postoperative complications. Other cases with long-term follow-up are needed to confirm and improve this crestal sinus lift technique.

Treatment alternatives for the rehabilitation of the posterior edentulous maxilla

Rehabilitation of the edentulous maxilla with implant-supported fixed dental prostheses can represent a significant clinical challenge due to limited bone availability and surgical access, among other factors. This review addresses several treatment options to replace missing teeth in posterior maxillary segments, namely the placement of standard implants in conjunction with maxillary sinus floor augmentation, short implants, tilted implants, and distal cantilever extensions. Pertinent technical information and a concise summary of relevant evidence on the reported outcomes of these different therapeutic approaches are presented, along with a set of clinical guidelines to facilitate decision-making processes and optimize the outcomes of therapy.

Effectiveness and complications of transcrestal sinus floor elevation using the cushioned grind-out technique: A retrospective cohort study with up to 7 years of follow-up

AIM

To evaluate the effectiveness and complications of the cushioned grind-out technique. The primary outcome was endo-sinus bone gain (ESBG), while secondary outcomes included the Schneiderian membrane perforation rate and mid- to long-term implant survival.

MATERIALS AND METHODS

In this retrospective study, we compared the cushioned grind-out technique with the classic osteotome technique, establishing statistical models to assess ESBG, membrane perforation rate and implant survival rate.

RESULTS

A total of 259 patients and 340 implants were included. The mean ESBG was 5.31 mm for the cushioned grind-out group and 4.64 mm for the osteotome group. Multivariable regression analysis revealed that the cushioned grind-out technique significantly facilitated ESBG (p = .028). Nineteen preparation sites experienced membrane perforation, with rates of 5.5% and 6.4% for the cushioned grind-out and osteotome groups, respectively. However, the difference was not statistically significant (p = .920). Additionally, the cumulative survival rate of the implants for 7 years was 95.2% and 91.4%, respectively, with the surgical technique not significantly influencing the results.

CONCLUSIONS

With 6 months to 7 years of post-prosthetic restoration review data, our findings show that the cushioned grind-out technique facilitates a higher ESBG, with no significant difference in membrane perforation or implant failure rate.

Evaluation of immediate implant placement with osteotome sinus floor elevation without graft material

Background

Significant difficulties can be encountered when installing posterior maxillary implants. Osteotome sinus floor elevation (OSFE) enables insertion of implants with insufficient bone height at the posterior maxilla using a special instrument known as the "osteotom."

Aim

This study aimed to evaluate the implant survival rates and radiographical bone gain data after OSFE with simultaneous implant placement performed without grafting material. Further, we have discussed whether the osteotom tapping distance to sinus floor affects the amount of new bone gain (NBG).

Materials and Methods

Forty dental implants were inserted in 36 patients (20 women and 16 men) aged between 24 and 80 years (mean = 55.7 years). Residual bone height and NBG were analyzed using a commercially available software program on panoramic films.

Results

The mean residual bone height at the intended implant sites was 5.4 mm ± 2.2 mm, ranging from 3.5 mm to 6.9 mm. The mean NBG was 1.5 mm ± 0.87 mm, ranging from 0.1 mm to 4 mm. At 64.4 months of follow-up, one implant had been lost in the osseointegration period. The remaining 39 implants were in function, with a survival rate of 97.5%. No significant difference was seen between the osteotome tapping distance to sinus floor and NBG at the implant apex (P = 0.395).

Conclusion

OSFE without using bone grafts with simultaneous implant installation is a safe and reliable method with successful long-term results for he rehabilitation of edentulous posterior maxillae.

Short and Ultra-Short Implants, in Association with Simultaneous Internal Sinus Lift in the Atrophic Posterior Maxilla: A Five-Year Retrospective Study

Recent short-term studies suggested the use of short and ultra-short implants in association with a modified osteotome sinus floor elevation (internal sinus lift) technique for the treatment of edentulous resorbed posterior maxilla. The aim of this retrospective study was to investigate this hypothesis in locking-taper implants with a mid-term follow-up of 5 years. Overall, 155 implants (32, 100, and 23 of, respectively, 5.0 mm, 6.0 mm, and 8.0 mm length) were positioned in the atrophic upper maxilla of 79 patients, and 151 implants were loaded with single crowns. Overall implant survival after 5 years was 94.84%. Implant survival for each length group was 93.75%, 94%, and 100% for 5.0, 6.0, and 8.0 mm length, respectively. Preoperative residual crestal bone height of 4.45 (1.3) mm increased to 9.25 (2.13) mm after implant placement and settled at 6.35 (1.73) mm after loading and at 5.25 (1.68) mm at follow-up. Elevation of the Schneiderian membrane was 4.8 (2.46) mm after implant placement, 3.06 (1.3) mm after loading, and 1.46 (1.06) mm at follow-up. Mean variations of peri-implant crestal bone loss and first bone-to-implant contact point were, respectively, -0.36 (1.3) mm and -0.62 (1.15) mm. It can be confirmed that internal sinus lift procedure revealed stable bone gain and negligible resorption at mid-term follow-up for atrophic upper crests with reduced height.

Minimal invasiveness in the transcrestal elevation of the maxillary sinus floor: A systematic review

In the attempt to reduce the invasiveness of a transcrestal sinus floor elevation procedure, different aspects must be considered; that is, the minimization of intra- and postsurgery morbidity, the reduction of treatment time, and the simplification/elimination of the reconstructive technology. Within this context, a systematic literature search was performed for controlled clinical trials evaluating the impact of one or more of these aspects on transcrestal sinus floor elevation invasiveness. Nineteen articles (15 studies) were included. Overall, the results confirmed that transcrestal sinus floor elevation is a minimally invasive and effective option for bone augmentation in the edentulous, atrophic posterior maxilla. By using powered instruments rather than manual osteotomes and hand mallet, the invasiveness of transcrestal sinus floor elevation can be further reduced without affecting its clinical effectiveness. To impact effectively on morbidity, the key elements to consider when selecting instruments for transcrestal sinus floor elevation are (a) their availability as a standardized sequence, to be adapted on predetermined residual bone height, and (b) the possibility to control pressure (eg, with screwable osteotomes) and/or instrument excursion (eg, with stop devices) to fracture the maxillary sinus floor. Among powered instruments, a standardized sequence of drills incorporating a trephine drill seem to be particularly indicated, due to reduced chair time, high tolerability for the patient, and the possibility to isolate a bone core to implement histomorphometric outcomes. At molar extraction sites with an interradicular septum characterized by a height of at least 4 mm, immediate transcrestal sinus floor elevation and implant placement can be considered a valid option to shorten treatment time.

Clinical and radiographic outcomes following transcrestal maxillary sinus floor elevation with injectable xenogenous bone substitute in gel form: a prospective multicenter study

Purpose

To investigate clinical and radiographic outcomes of transcrestal maxillary sinus floor elevation performed with an injectable xenograft in gel form, analyzing general, local and surgical variables possibly influencing the results.

Methods

Patients with residual crestal height < 5 mm underwent transcrestal sinus floor elevation with xenograft in gel form to allow the placement of a single implant. Simultaneous implant placement was performed when primary stability was ≥ 15 Ncm. Graft height was measured immediately after surgery (T0) and after 6 months of healing (T1). Univariate and multivariate regression models were built to assess associations between clinical variables with implant survival and graft height at T1.

Results

71 patients underwent transcrestal sinus floor elevation and 54 implants were simultaneously placed. Delayed implant placement (at T1) was possible in 5 cases out of 17 (29.4%), whereas in 12 patients (70.6%) implant insertion was not possible or required additional sinus grafting. Implant survival rate, with a follow-up varying from 12 to 32 months after loading, was 100%. Mean pre-operative bone height was 3.8 ± 1.0 mm, at T0 was 13.9 ± 2.2 mm and at T1 was 9.9 ± 2.8 mm. Bone height at T1 was negatively influenced by membrane perforation at surgery (p = 0.004) and positively influenced by immediate implant insertion (p < 0.001).

Conclusions

Transcrestal sinus floor elevation performed with injectable xenograft gel resulted in 100% implant survival rate. However, immediate implant insertion seems a crucial factor to preserve vertical bone gain: one-stage technique seems to be the most predictable approach to optimize clinical outcomes with this approach.

Trial registration clinicaltrials.gov, NCT05305521. Registered 31 March 2022—Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT05305521.

Intraoperative complications and early implant failure after transcrestal sinus floor elevation with residual bone height ≤5 mm: A retrospective multicenter study

OBJECTIVE

Clinical indications for maxillary sinus floor elevation with transcrestal techniques have increased in recent years even in sites with minimal residual bone height (RBH). Nevertheless, limited information is currently available on incidence of intraoperative complications and early implant failure in these cases.

MATERIAL AND METHODS

This retrospective multicenter study was performed on anonymized clinical and radiographic records of patients who underwent transcrestal sinus floor elevation in seven clinical centers. Influence of different factors related to patient, sinus anatomy and surgical technique on the incidence of intraoperative complications and early implant failure rate after transcrestal sinus lift were investigated.

RESULTS

A total of 430 patients treated with transcrestal sinus floor elevation for single implant insertion in sites with RBH ≤5 mm were included in the final analysis. After one year of loading, 418 implants out of 430 were satisfactorily in function. Early implant failure was recorded in 12 cases (2.8%), resulting significantly associated with the presence of large sinus cavities and with the occurrence of membrane perforation. The following adverse events were recorded: membrane perforation (7.2%), acute sinusitis (0.9%), implant displacement into the sinus cavity (0.7%), oro-antral fistula (0.2%) and benign paroxysmal positional vertigo (0.5% of osteotome cases). A strong direct correlation between sinus membrane perforation and bucco-palatal sinus width (p=0.000) was demonstrated.

CONCLUSIONS

Early implant failure after transcrestal sinus elevation showed significant direct correlation with bucco-palatal maxillary sinus width and the presence of membrane perforation. Sinus membrane perforation was strongly associated with bucco-palatal sinus width (extremely low perforation rate in narrow and much higher incidence in wide sinuses).

Clearance of Bone Substitute in Gel Form Accidentally Dispersed into the Sinus Cavity during Transcrestal Maxillary Sinus Floor Elevation: Two-Case Report

Sinus membrane perforation is the most frequent intraoperative complication occurring during maxillary sinus floor elevation. Although numerous techniques for perforation management are present, grafting material dissemination may still occur, representing a potential trigger factor leading to acute or chronic sinusitis. This case report describes two cases of xenogeneic bone substitute in gel form accidentally dispersed into the sinus cavity during maxillary sinus floor elevation with a transcrestal approach. In both cases, immediately postoperative radiographic imaging showed an important amount of gel graft dislodged into the sinus cavity as a consequence of hidden perforations that remained undetected during surgery. Patients were monitored for 6 months after surgery and reported no signs or symptoms related to possible sinus disease. Control radiographs showed no sinus membrane hypertrophy and/or presence of residual disseminated gel, confirming complete clearance of the accidentally dispersed graft through the ostiomeatal complex. In order to minimize postoperative complications, bone substitutes in gel form could represent an interesting alternative to granular grafts for their easier clearance from the maxillary sinus cavity in case of accidental dissemination during sinus augmentation procedures.

Preliminary Study with the Use of a Titanium Mesh as Space Maker and Implant Primary Stabilization for One-Stage Sinus Lift in Cases with Less Than 1.5 mm Residual Bone

(1) Background: In the lateral area of the maxilla, the alveolar bone can lose significant volume due to maxillary sinus pneumatization following teeth extractions. This preliminary study evaluated the effectiveness of a novel technique for one-stage sinus lifting and simultaneous implant placement in cases with less than 1.5 mm residual alveolar bone. The subsequent survival rate at 1-year post-occlusal loading was assessed. (2) Methods: 15 patients were selected, the main inclusion criteria were the partially edentulous area in the posterior maxilla with alveolar bone height of less than 1.5 mm below the sinus. All of the patients underwent one-stage sinus lifting, along with simultaneous implant placement using a “butterfly” anchorage device to optimize the primary stability and xenograft bone as graft material. At 6 to 9 months after surgery, the anchorage device was removed and implants were loaded. Panoramic x-ray images were used to assess the new bone formation, while the biological stability was measured using resonance frequency analysis. (3) Results: 15 implants were inserted. The mean implant stability quotient (ISQ) value was 71.3 (SD = ±2.51) and the mean healing period was 7.3 (SD = ±1.23) months. The mean bone height after the healing period was 14.4 (SD = ±2.05). A statistically significant correlation was found between the healing period and the ISQ value (Spearman rho = 0.684, sig. = 0.005). No statistically significant correlation was found between the ISQ value and the new regenerated bone height (Person r = 0.389, sig. = 0.152). Smoking was identified as a risk factor involved in postoperative complications. (4) Conclusions: The results of the present preliminary study demonstrated that the proposed “butterfly” technique was effective when performing one-stage sinus lifting and simultaneous implant placement in cases with less than 1.5 mm of residual alveolar bone. The survival rate was 100% at 1-year post occlusal loading.

Different techniques in transalveolar maxillary sinus elevation: A literature review

Dental implant treatment in the posterior maxilla encounters bone quality and quantity problems. Sinus elevation is a predictable technique to overcome height deficiency in this area. Transalveolar sinus elevation is a technique that is less invasive and less time-consuming, first introduced for ridges with at least 5 mm of bone height. Many modifications and innovative equipment have been introduced for this technique. This review aimed to explain the modifications of this technique with their indications and benefits.

An exhaustive search in PubMed Central and Scopus electronic databases was performed until December 2020. Articles were selected that introduced new techniques for the transalveolar maxillary sinus approach that had clinical cases with full texts available in the English language. Finally, twenty-six articles were included. The data were categorized and discussed in five groups, including expansion-based techniques, drill-based techniques, hydraulic pressure techniques, piezoelectric surgery, and balloon techniques.

The operator’s choice for transalveolar approach techniques for sinus floor elevation can be based on the clinician’s skill, bone volume, and access to equipment. If possible, a technique with simultaneous implant placement should be preferred.

Bone Grafting for Implant Surgery

Osseous grafting serves to restore form and function to craniofacial defects. These grafts have been used with the aim of enhancing osteoinductive, osteoconductive, and osteogenic properties to address vertical and horizontal defects so as to render the edentulous ridge more amenable to implant placement. As the biology of bone grafts continues to be unearthed, the use of adjuvants to augment grafts has proved effective. Three-dimensional printing, tissue engineering with the use of stem cells, immunotyping and hormonal therapy all hold promise for the future in the thrust to discover the ideal graft.

[The alveolar antral artery prevalence and topography according to literature review]

INTRODUCTION

The lack of the available bone in the posterior maxilla is determined by the range of anatomical and topographical factors. Lateral sinus floor elevation is the procedure for vertical augmentation in this region. Several complications may occur while performing a lateral sinus lift and bleeding due to alveolar antral artery (AAA) damage is one of them.

The aim of the study is to analysis the different literature on AAA topographical features on cadaver species and on radiographic methods.

MATERIALS AND METHODS

A search of the English language literature was performed by three independent readers in the PubMed electronic database. Articles published between 2013 and 2018 on cadaver and radiographic studies were included.

RESULTS

The analysis included 9 articles. AAA prevalence in cadavers was 100% but AAA bone signs in CBCT studies varied between 32% and 93%. The diameter varied from 0.91 mm to 3.6 mm, and the distances from AAA to the sinus floor and to the alveolar ridge crest were 7.38-9.97 and 14.6-18.66 mm respectively.

CONCLUSION

Our literature analysis showed the difference between AAA prevalence in cadavers and in CBCT scans. The results show that even proper pre-operative planning of the lateral sinus lift with CBCT cannot guarantee avoiding AAA damage while performing the surgery.

Platform switch hybrid zygoma implants improve prosthetics and marginal bone protection after extra-sinus placement

PURPOSE

The aim of our studdy is clinical evaluation of Platform switch hybrid zygoma implants.

MATERIALS AND METHODS

117 zygomatic implants were followed up during this time. They included 55 Brånemark System zygoma implants, 38 Noris implants, and 24 novel iRES hybrid implants with platform switch.

RESULTS

Bone quality and quantity are the prerequisite for successful implant treatment. Zygomatic implants are intended for patients with severely resorbed maxilla that cannot accommodate conventional implants without prior extensive bone grafting. Such regenerative procedures, like sinus lifts, prolong implant rehabilitation to several months (12-18). Furthermore, extensive grafts are less predictable showing varying degrees of graft resorption. Zygoma implants enable full, often immediate, reconstruction of the upper dental arch without the need for sinus lift treatment. The original zygoma protocol runs the implants through the sinus, requires general anesthesia, and positions the prosthetic platform of the implants on the palate, which makes prosthesis cumbersome. It also induces risk for post-op sinusitis. Extra-sinus approach with novel zygoma hybrid implants bypasses sinuses and positions the implant prosthetic platform on the crest allowing for same good prosthetics as on conventional dental implants. Furthermore, crestal threads and a platform-switch, of the novel zygoma design, increase implant anchorage and minimize marginal bone loss. The study presents evolution of zygoma implant rehabilitation protocol and zygoma implant design in our clinical practice over 15 years (2004-2019).

CONCLUSION

Extra-sinus zygomatic implant placement lowers the risk of post-op sinusitis and makes procedure possible to be done in local anesthesia.

Minimally-Invasive Endoscopic-Assisted Sinus Augmentation

OBJECTIVES

The purpose of this article is to evaluate endoscopic-assisted technique by lateral approach for sinus floor augmentation, to reduce the incidence of Schneiderian membrane perforation, and to guarantee a sufficient apposition of new bone even in the posterior maxillary sinus.

METHODS

From January 2017 to December 2017, 10 patients affected by severe maxillary atrophy underwent endoscopic-assisted sinus augmentation using a lateral approach.

RESULTS

In only 1 patient, a little perforation of sinus membrane was observed intraoperatively and it was repaired. No abnormal postoperative bleeding was observed. None of the patients experienced oro-antral fistula, infection, or V2 dysesthesia. The authors did not find radiologic evidences of biomaterial displaced on the maxillary sinus or postoperative sinusitis.

CONCLUSIONS

The authors evaluated endoscopic-assisted maxillary sinus augmentation technique using a lateral approach that allows a direct and clear view of the surgical field. This technique, as the preliminary results demonstrate, is safe and helpful, especially in avoiding membrane perforation and in xenograft optimal distribution. It could be very useful in retreatment patients.

The Low Window Sinus Lift: A CAD-CAM-Guided Surgical Technique for Lateral Sinus Augmentation: A Retrospective Case Series

INTRODUCTION

Recently, a rational design of the window osteotomy, the "Low Window" technique, was proposed to facilitate sinus augmentation and reduce postsurgical patient discomfort; this article aims to evaluate its safety and effectiveness.

MATERIALS AND METHODS

Records were assessed retrospectively for patients who had sinus lifts using the low window approach, followed by implant placement and prosthetic rehabilitation. Outcomes analyzed were implant and prosthetic success and survival rates and rate of complications. Patients also provided their subjective evaluation on postoperative pain and swelling.

DISCUSSION

Records of 22 patients who had 28 interventions (79 implants) were assessed. Average follow-up was 38.4 ± 13.2 months. No cases of intraoperative sinus membrane perforation or other complications occurred, and patients reported a high degree of satisfaction. At the final follow-up, all prostheses and implants were successful.

CONCLUSION

The low window sinus lift seems to be an effective technique for reducing the risk of sinus-membrane perforation and patient postsurgical discomfort in lateral sinus augmentation. Prospective, comparative studies are needed to investigate whether the technique is more advantageous than the traditional lateral osteotomy and flap-preparation approaches.

The use of mineralized bone allograft as a single grafting material in maxillary sinus lifting with severely atrophied alveolar ridge (1-3 mm) and immediately inserted dental implants. A 3- up to 8-year retrospective study

OBJECTIVE

The primary aim of our study was to evaluate the efficacy of mineralized bone allograft alone in sinus floor augmentation with simultaneous implant placement in cases with severe atrophy of the residual maxillary bone (bone height < 4 mm).

METHODS

Thirty-five dental implants were placed in 29 patients who underwent sinus augmentation via traditional lateral window technique from 2008 to 2013. Patients with residual alveolar height between 1 and 3 mm at the site of implantation were included in the study. The height of residual bone was initially estimated by plain panoramic X-ray and reevaluated intraoperatively by precise micrometric measurement at the site of implantation. Implants of 13 mm height and 3.5 or 4.3 mm in diameter were inserted simultaneously. Mineralized bone allograft was used alone to augment the sinus floor.

RESULTS

No wound dehiscence was recorded. In one case there was a postoperative site infection which subsided with antibiotics without implant failure. One implant migrated during the postoperative period to the maxillary sinus and was removed. One implant failed. The remaining 33 implants were successfully loaded. Follow-up ranged from 3 to 8 years.

CONCLUSIONS

Maxillary sinus lift in severely absorbed alveolar ridges with simultaneous implant placement could be safely performed using mineralized allograft alone, rendering the procedure less invasive and less time-consuming.

Alveolar Crestal Approach for Maxillary Sinus Membrane Elevation with <4 mm of Residual Bone Height: A Case Report

Introduction

For maxillary sinus membrane elevation (MSME), the lateral window approach and crestal approach are available, and high success rates have been achieved with low residual bone height as a development of technology.

Objective

To evaluate MSME using the crestal approach with a rotary-grind bur (RGB (including reamer or sinus bur)) in patients with residual bone height of <4 mm.

Materials and Methods

Ten implants were placed in 10 patients with residual bone height of <4 mm, by sinus elevation using an RGB. The implant stability quotient (ISQ) was measured immediately after implant placement (ISQ 1) and before taking impression for the final prosthesis (ISQ 2). The extent of marginal bone loss was measured on periapical radiographs.

Results

The mean residual bone height before implant placement was 3.41 ± 0.53 mm; no complications, including membrane perforation, severe postoperative pain, or discomfort, occurred either during or after surgery. The mean ISQ 1 was 63.4 ± 12.1, whereas the mean ISQ 2 was 77.6 ± 5.8. The mean marginal bone resorption was 0.23 ± 0.18 mm on periapical radiographs.

Conclusions

MSME using the crestal approach with an RGB is a reliable technique for implant placement in sites where available bone is insufficient.

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.

New bone formation after transcrestal sinus floor elevation was influenced by sinus cavity dimensions: A prospective histologic and histomorphometric study

OBJECTIVE

The aim of this multicenter prospective study was to analyze clinically and histologically the influence of sinus cavity dimensions on new bone formation after transcrestal sinus floor elevation (tSFE).

MATERIAL AND METHODS

Patients needing maxillary sinus augmentation (residual crest height <5 mm) were treated with tSFE using xenogeneic granules. Six months later, bone-core biopsies were retrieved for histological analysis in implant insertion sites. Bucco-palatal sinus width (SW) and contact between graft and bone walls (WGC) were evaluated on cone beam computed tomography, and correlations between histomorphometric and anatomical parameters were quantified by means of forward multiple linear regression analysis.

RESULTS

Fifty consecutive patients were enrolled and underwent tSFE procedures, and forty-four were included in the final analysis. Mean percentage of newly formed bone (NFB) at 6 months was 21.2 ± 16.9%. Multivariate analysis showed a strong negative correlation between SW and NFB (R²  = .793) and a strong positive correlation between WGC and NFB (R²  = .781). Furthermore, when SW was stratified into three groups (<12 mm, 12 to 15 mm, and >15 mm), NFB percentages (36%, 13% and 3%, respectively) resulted significantly different.

CONCLUSIONS

This study represented the first confirmation based on histomorphometric data that NFB after tSFE was strongly influenced by sinus width and occurred consistently only in narrow sinus cavities (SW <12 mm, measured between buccal and palatal walls at 10-mm level, comprising the residual alveolar crest).

Influence of Maxillary Sinus Width on New Bone Formation After Transcrestal Sinus Floor Elevation: A Proof-of-Concept Prospective Cohort Study

PURPOSE

Graft maturation in the maxillary sinus requires adequate angiogenesis and osteoprogenitor cells migration from the surrounding bony walls: the aim of this study was to analyze the correlation between sinus cavity dimensions and new bone formation after transcrestal sinus floor elevation (tSFE).

METHODS

Patients needing maxillary sinus augmentation (residual crest height ≤ 4 mm) were treated with tSFE using xenogeneic granules. Six months later, bone-core biopsies were retrieved for histological analysis in the implant insertion sites. Buccopalatal sinus width (SW) was evaluated on cone beam computed tomography, and correlations between histomorphometric and anatomical parameters were quantified by means of linear regression analysis.

RESULTS

Eight consecutive patients underwent tSFE procedures: at 6 months, average percentage of newly formed bone resulted 24.2% ± 7.9%. Statistical analysis showed a strong inverse correlation between SW and new bone formation (R = 0.88), and a strong direct correlation between the number of exposed bone walls and new bone formation (R = 0.82).

CONCLUSION

Within the limitations of this proof-of-concept study, in which a restricted number of patients were analyzed, tSFE showed more predictable results in narrow than in large sinuses, in terms of new bone formation.

Recent advances in dental implants

Dental implants are a common treatment for the loss of teeth. This paper summarizes current knowledge on implant surfaces, immediate loading versus conventional loading, short implants, sinus lifting, and custom implants using three-dimensional printing. Most of the implant surface modifications showed good osseointegration results. Regarding biomolecular coatings, which have been recently developed and studied, good results were observed in animal experiments. Immediate loading had similar clinical outcomes compared to conventional loading and can be used as a successful treatment because it has the advantage of reducing treatment times and providing early function and aesthetics. Short implants showed similar clinical outcomes compared to standard implants. A variety of sinus augmentation techniques, grafting materials, and alternative techniques, such as tilted implants, zygomatic implants, and short implants, can be used. With the development of new technologies in three-dimension and computer-aided design/computer-aided manufacturing (CAD/CAM) customized implants can be used as an alternative to conventional implant designs. However, there are limitations due to the lack of long-term studies or clinical studies. A long-term clinical trial and a more predictive study are needed.

Sinus Grafts: Science and Techniques-Then and Now

INTRODUCTION

Sinus lifts have been around for more than four decades now, and the amount of changes that we have seen in techniques and armamentarium coupled with the advent of newer materials is worth taking note of.

MATERIALS AND METHODS

A complete review of the literature was done since the advent of ways and means to augment the posterior maxilla with a run through of various advantages and disadvantages of the same.

CONCLUSION

In conclusion, we can say that this procedure is today very predictable and offers clinicians a possibility to rehabilitate the posterior maxilla with implant-based solutions.

A Rational Approach to Sinus Augmentation: The Low Window Sinus Lift

Sinus augmentation is a well-known approach to treating alveolar bone ridge atrophy in the posterior maxilla. The preparation of the lateral window is crucial. Its size, design, and position in the vestibular sinus wall may affect the intra- and postsurgical complication rates and affect the intrasurgical activity of both surgeons and assistants. The present paper describes a rational technique that also exploits the guided surgery approach for design and preparation of a lateral window for sinus augmentation, the Low Window Sinus Lift. To illustrate the use of this approach, a case is presented in which the 50-year-old patient had the left maxillary first molar extracted, followed two months later by sinus augmentation and placement of three implants. One year after delivery of the definitive prosthesis, all three implants were successful, and the prosthesis was fully functional. Controlled studies should be undertaken to assess whether this technique provides significant advantages compared to other sinus augmentation approaches.

Stage Characterization and Marginal Bone Loss Evaluation Up to 96 Months of Crestal Sinus Augmentation With Sequential Drills: A Retrospective Study

INTRODUCTION

The 2-stage crestal approach to augment the maxillary sinus is a little-used technique. The aim of this retrospective study was to assess events characterizing stages of this technique after implant placement in the posterior maxilla with residual bone height less than 4 mm and evaluate the marginal bone loss (MBL) changes over time.

MATERIAL AND METHODS

Thirty-three patients underwent unilateral sinus augmentations using the trancrestal technique with mineralized allograft. Six-months (6 m) after first surgery, if skeletal subsidence prevented insertion of a 10-mm-length implant, additional grafting was performed during implant (n = 33) insertion. Radiographs were taken before grafting (baseline), immediately after and at 6 months; immediately after and 6 months after implant placement; and at follow-up (24-96 m).

RESULTS

One implant was lost (ISR = 96.97%). Of the remaining 32 patients, 14 (A group) underwent standard implant placement, whereas 18 (B group) underwent additional grafting immediately before implant placement. Given that B-group patients initially obtained lower crestal bone height after first surgery, additional grafting procedures provided greater crestal height in the B group. A significant relationship between ending (eMBL) and 6mMBL was found in both groups, with greater values in the B group. However, in both groups, eMBL was always greater if 6mMBL was greater than 0.44 mm.

DISCUSSION

Results suggest a high and low skeletal-reactivity patient categorization. In both patient categories, MBL greatly depends upon 6-month values. Investigations are necessary to relate sinus size with results obtained by this 2-stage crestal approach.

CONCLUSIONS

The 2-stage crestal sinus lift procedure not only provides predictable results, but also allows low skeletal-reactivity patient recovery.

Sinus floor elevation utilizing the transalveolar approach

A transalveolar approach for sinus floor elevation with subsequent placement of dental implants was first suggested by Tatum in 1986. In 1994, Summers described a different transalveolar approach using a set of tapered osteotomes with increasing diameters. The transalveolar approach of sinus floor elevation, also referred to as 'osteotome sinus floor elevation', the 'Summers technique' or the 'Crestal approach', may be considered as being more conservative and less invasive than the conventional lateral window approach. This is reflected by the fact that more than nine out of 10 patients who experienced the surgical procedure would be willing to undergo it again. The main indication for transalveolar sinus floor elevation is reduced residual bone height, which does not allow standard implant placement. Contraindications for transalveolar sinus floor elevation may be intra-oral, local or medical. The surgical approach utilized over the last two decades is the technique described by Summers, with or without minor modifications. The surgical care after implant placement using the osteotome technique is similar to the surgical care after standard implant placement. The patients are usually advised to take antibiotic prophylaxis and to utilize antiseptic rinses. The main complications reported after performing a transalveolar sinus floor elevation were perforation of the Schneiderian membrane in 3.8% of patients and postoperative infections in 0.8% of patients. Other complications reported were postoperative hemorrhage, nasal bleeding, blocked nose, hematomas and benign paroxysmal positional vertigo. Whether it is necessary to use grafting material to maintain space for new bone formation after elevating the sinus membrane utilizing the osteotome technique is still controversial. Positive outcomes have been reported with and without using grafting material. A prospective study, evaluating both approaches, concluded that significantly more bone gain was seen when grafting material was used (4.1 mm mean bone gain compared with 1.7 mm when no grafting material was utilized). In a systematic review, including 19 studies reporting on 4388 implants inserted using the transalveolar sinus floor elevation technique, the 3-year implant survival rate was 92.8% (95% confidence interval: 87.4-96.0%). Furthermore, a subject-based analysis of the same material revealed an annual failure rate of 3.7%. Hence, one in 10 subjects experienced implant loss over 3 years. Several of the included studies demonstrated that transalveolar sinus floor elevation was most predictable when the residual alveolar bone height was ≥ 5 mm and the sinus floor anatomy was relatively flat.

Two-stage crestal sinus elevation by sequential drills in less than 4 mm of residual ridge height: a clinical and histologic case report

PURPOSE

The aim of this work, the first human histologic case report of this technique, was a clinical and histologic evaluation of implant placed in a severely atrophic maxilla using a 2-stage crestal sinus elevation.

CASE PRESENTATION

A 52-year-old woman required rehabilitation of an atrophic maxilla with a fixed implant-supported prosthesis. At the first surgery, a crestal sinus lift was performed using beta-tricalcium phosphate (β-TCP), as radiographic tracer, and mineralized human bone allograft (MHBA) as grafting material. After 6 months, a bone core biopsy was taken, and 2 implants were placed in the augmented sites. Four months later, implants were exposed, and 2 splinted gold-porcelain crowns were delivered. Histology highlighted basal bone disappearance, replaced by a wide composite network (∼50% vol/vol) of MHBA granules connected by newly formed bone, and osteoblastic activities.

CONCLUSION

This case report demonstrates the possibility of executing a staged transcrestal sinus lift in atrophic situations. MHBA evidenced usefulness in maintaining bone volume. Histologic analyses confirmed the sound outcome of the graft augmentation. Additional studies would be beneficial to confirm or refute the reliability of this technique.

Transcrestal Sinus Lift Procedure Approaching Atrophic Maxillary Ridge: A 60-Month Clinical and Radiological Follow-Up Evaluation

Aim. The aim of this study was to assess the success and the survival rate of dental implants placed in augmented bone after sinus lifting procedures. Material and Methods. 31 patients were mainly enrolled for a residual upper jaw crest thickness of 3 mm. CBCT scans were performed before and after the augmentation technique and at the follow-up appointments, at 3, 6, 12, 24, and up to 60 months. The follow-up examination included cumulative survival rate of implants, peri-implant marginal bone loss, and the height of sinus floor augmentation. Results. This retrospective study on 31 patients and 45 implants later inserted in a less than 3 mm crest showed excellent survival rates (99.5%), one implant was lost before loading due to an acute infection after 24 days, and two implants did not osteointegrate and were removed after 3 months. The radiological evaluation showed an average bone loss of 0.25 mm (±0.78 mm) at the first follow-up appointment (3 months) up to 0.30 mm (±1.28 mm) after 60-month follow-up. Conclusion. In this study it was reported how even in less than 3 mm thick crest a transcrestal technique can predictably be used with a long-term clinical and radiological outcome, giving patients excellent stability of the grafted material and healthy clinical results.

Transcrestal guided sinus lift without grafting materials: a 36 months clinical prospective study

PURPOSE

This study describes the ability to perform a technique for bone regeneration in maxillary posterior deficit (TGSL) without the use of bone grafting materials using a highly minimally invasive protocol.

MATERIALS AND METHODS

Sixty six implants have been inserted in the sinus floor of a total of 39 patients through the transcrestal guided sinus lift technique (TGSL). All patients have been followed for at least three years in function. The drilling protocol was adapted on the basis of bone density of each implant site to achieve a torque between 45 and 55 Ncm. Healing titanium abutments tightened to 35 Ncm have been used. A CAD/CAM metal ceramics final prosthetic restoration has been generated a six months after the tissues healing and the provisional functionalization of the occlusion. Survival rate of implants and prostheses, biological and biomechanical complications, changes in marginal bone levels, and total height of alveolar crest bone before and after surgery have been evaluate and measured by the results obtained in this prospective study. It was also measured the periodontal parameters as well as levels of perception of pain by the patient during the entire recovery period.

RESULTS

The result of the data of follow-up was 41.96 (24 to 36) months. Cumulative implant survival was 98.53% at 3 years. There were no biological and mechanical complications and there were no prosthetic failures during the whole period of follow-up. The Marginal Bone Loss (MBL) average during the first year of operation was from 0.33 to 0.36 mm, while the 3-year follow-up, the MBL average was 0.51 to 0.29 mm. The average of residual bone height of alveolar ridge before treatment was 6.7 to 1.6 mm (range 5.1 to 9.2 mm), while the average bone height was gained 6,4 - 1.6 mm (range 3.2 to 8.1 mm). All patients reported lower pain levels and found to have normal periodontal parameters.

CONCLUSIONS

This study suggests that the use of guided surgery to perform transcrestal maxillary sinus lift to increase the sub-antral crestal height is a minimally invasive technique of success for the short and medium-term of follow-up, thus avoiding the extended treatment time and reducing the morbidity associated with the lifting of the floor of the maxillary sinus with traditional technique using bone grafting materials. Furthermore, this protocol without the use of graft materials does not vary the final outcome that have demonstrated the presence of newly formed bone around implants offering always predictable results, and giving a further reduction in the costs of the procedure rehabilitation.

Effects of Nd:YAG laser irradiation for minimizing edema and pain after sinus lift surgery: randomized controlled clinical trial

OBJECTIVE

The aim of the present study was to evaluate the effectiveness of neodymium-doped yttrium aluminum garnet (Nd:YAG) laser used for low-level laser therapy (LLLT) on pain, oral health-related quality of life (OHRQoL), and swelling after sinus lift procedure.

MATERIALS AND METHODS

Ten healthy patients, requiring bilateral direct sinus lift surgery, were included in this prospective, randomized study. The treatment sides were randomly assigned to LLLT or control groups. The experimental side received 8 J/cm(2) of energy density, a wavelength of 1064 nm, for 60 sec, and 0.5 W laser immediately after surgery. Swelling, pain perception, and OHRQoL were evaluated at different time intervals. The data were analyzed by the one way ANOVA.

RESULTS

Evaluations of postoperative pain, OHRQoL, and swelling were made. We observed that the swelling and the OHRQoL in the Nd:YAG group were significantly improved when compared with the control group on the 3rd day after surgery (p<0.05). The pain levels after surgery was almost the same for both groups, without statistically significant differences (p>0.05). There were no statistically significant differences between groups with regard to any of the parameters evaluated on the 7th day.

CONCLUSIONS

The results demonstrate that the 1064 nm Nd:YAG laser was effective in improving OHRQoL and reducing swelling after sinus lift surgery. Within the limitations of this study, we concluded that the 1064 nm Nd:YAG laser has beneficial effects on swelling and OHRQoL, making it suitable for LLLT.

Incremental, transcrestal sinus floor elevation with a minimally invasive technique in the rehabilitation of severe maxillary atrophy. Clinical and histological findings from a proof-of-concept case series

In the posterior maxillary sextants, the residual dimensions of the edentulous ridge can considerably limit the insertion of implants with the desired length and diameter. A minimally invasive procedure for transcrestal sinus floor elevation (tSFE), namely the Smart Lift technique, which is based on a standardized sequence of specifically designed drills and osteotomes, was introduced in 2008 and subsequently validated in a series of recent studies. The present technical note describes the use of the technique by a staged approach, called incremental tSFE (i-tSFE), in the augmentation of severely resorbed edentulous ridges. The i-tSFE consists of 2 staged tSFE procedures performed with a transcrestal access, the second of which is performed concomitantly with implant placement. In the present case series, 3 patients with severe bone atrophy (residual bone height, 2 to 3 mm) in the edentulous posterior maxilla were treated with i-tSFE. At the second surgical stage of i-tSFE, implants at least 8 mm long were placed at all sites, and the success of the implant-supported restoration was monitored to 6 months (1 patient) or 3 years (2 patients). Histologic findings from an augmented site showed the presence of newly formed bone, bone marrow spaces with numerous vascular canals, and residual graft particles occupying approximately 50%, 15%, and 35% of the total area, respectively. The results of the study showed that i-tSFE can be performed successfully with the Smart Lift technique to rehabilitate atrophic maxillary posterior sextants.

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 rehabilitation for atrophic maxilla: a review

A severely atrophied maxilla presents serious limitations for conventional implant placement. This presents challenge to the surgeon for implant placement in harmony with the planned prosthesis. Survey of various literatures using internet sources, manual searches, and common textbooks on dental implants shows, that a thorough knowledge of conventional augmentation procedures such as bone augmentation techniques, guided bone regeneration, alveolar distraction, maxillary sinus elevation techniques with or without grafting and contemporary techniques of implant placement provide effective long-term solutions in the management of the atrophic maxilla.

Radiographic analysis of a transalveolar sinus-lift technique: a multipractice retrospective study with a mean follow-up of 5 years

BACKGROUND

Various sinus-lift techniques have been described in the literature. The aim of this retrospective study is to evaluate the efficacy of a transalveolar sinus-lift technique in terms of implant survival, marginal bone loss, and complications.

METHODS

A total of 538 patient records were examined, and after applying exclusion and inclusion criteria, a sample of patients was included with a mean follow-up of 5 years. Implants with a smooth or tapered surface were considered. Therefore, only sinus lifts with inorganic bovine bone matrix or demineralized bone matrix were included, and 1,536 periapical radiographs were analyzed. Outcome measures were implant success, implant failure (peri-implantitis and loss of osseointegration), marginal bone resorption, and biologic complications (membrane perforations, sinusitis, and intraoperative and/or postoperative hemorrhage). Periapical radiographs were evaluated before surgery, post-surgery, and after 6 months and 1, 3, and 5 years. We analyzed the residual crestal bone height under the sinus, the amount (mm) of height increase after surgery, and values of implant marginal bone resorption for considered follow-ups.

RESULTS

Two hundred eighty-two (282) patients were excluded. Therefore, 256 patients treated with the transalveolar sinus-lift technique were included. A total of 376 dental implants and 323 sinus lifts were analyzed. The overall rates of implant success and failure were 94.9% and 5.1%, respectively. The mean bone loss around implants was 1.98 mm (mean follow-up of 5 years). Patients treated with inorganic bovine bone matrix showed a better implant success rate (P = 0.03) than did patients treated with demineralized human matrix. Three Schneiderian membrane perforations occurred in the 323 sinus lifts. In these cases, the surgeon performed another surgical operation after 3 months. Postoperative complications were peri-implantitis (six cases) and osseointegration losses (13 cases).

CONCLUSIONS

The transalveolar sinus-lift technique was a safe, minimally invasive technique with an implant success rate comparable to traditional implantology. The implant success rate was positively affected by the low-resorption graft material, and a low bone-resorption rate around implants was found.

Piezoelectric surgery in maxillary sinus floor elevation with hydraulic pressure for xenograft and simultaneous implant placement

Because of the low bone quality in the posterior maxilla, edentulism in this area often results in a resorbed osseous structure and a pneumatized maxillary sinus, which makes dental implant surgery in the posterior maxilla a challenge. Two main surgical approaches are available for the sinus lift procedure: lateral and crestal. Improvement of the maxillary sinus floor elevation technique and increase in predictability are desirable. This article describes an innovative approach to maxillary sinus floor elevation with piezoelectric surgery and hydraulic pressure for xenograft and simultaneous implant placement in situations with insufficient residual alveolar bone.

Peri-implant bone length changes and survival rates of implants penetrating the sinus membrane at the posterior maxilla in patients with limited vertical bone height

Purpose

The aim of this study was to measure the peri-implant bone length surrounding implants that penetrate the sinus membrane at the posterior maxilla and to evaluate the survival rate of these implants.

Methods

Treatment records and orthopantomographs of 39 patients were reviewed and analyzed. The patients had partial edentulism at the posterior maxilla and limited vertical bone height below the maxillary sinus. Implants were inserted into the posterior maxilla, penetrating the sinus membrane. Four months after implant insertion, provisional resin restorations were temporarily cemented to the abutments and used for one month. Then, a final impression was taken at the abutment level, and final cement-retained restorations were delivered with mutually protected occlusion. The complications from the implant surgery were examined, the number of failed implants was counted, and the survival rate was calculated. The peri-implant bone lengths were measured using radiographs. The changes in initial and final peri-implant bone lengths were statistically analyzed.

Results

Nasal bleeding occurred after implant surgery in three patients. No other complications were found. There were no failures of the investigated implants, resulting in a survival rate of 100%. Significantly more bone gain around the implants (estimated difference=-0.6 mm, P=0.025) occurred when the initial residual bone height was less than 5 mm compared to the >5 mm groups. No significant change in peri-implant bone length was detected when the initial residual bone height was 5 mm or larger.

Conclusions

This study suggests that implants penetrating the sinus membrane at the posterior maxilla in patients with limited vertical bone height may be safe and functional.

Performance of coralline hydroxyapatite in sinus floor augmentation: a retrospective study

OBJECTIVE

The purpose of this study is to retrospectively explore the utilization of coralline hydroxyapatite in maxillary sinus augmentation.

METHOD

One hundred and eighteen cases of sinus lift with coralline hydroxyapatite (CHA) were included in this study. In detail, simultaneous implantation was conducted in 78 patients (174 implants) and delayed implantation was done in 40 cases (82 implants) around 6 months after bone transplantation. The clinical features and X-ray radiographs after operation were analyzed to evaluate osseointegration procedures according to a planned medical follow-up. In the delayed group, around 6 months, a bone biopsy was taken just during implant placement in order to evaluate the new formed bone from a histological and histomorphometrical point of view. A further 6 months later, abutment connection was performed, and the patients received prosthetic restoration of the missing teeth.

RESULT

Clinically, the incisions healed well. No abnormal reactions were found during follow-up period. All the 174 simultaneous implants were successful after 1-5 years of medical review; Out of 82 delayed implants, 3 were found to be loose. Histologically, all the specimens showed signs of active remodeling, and all the tissues had a large amount of osteocyte at sixth month after sinus augmentation. New bone formed dramatically. Radiologically, the density of CHA gradually reduced since the beginning of the third month, and CHA may be completely resolved at about fifth year.

CONCLUSION

CHA is proven an ideal bone graft material for its reliable clinical results and favorable histocompatibility in the treatment of sinus atrophy or other kinds of insufficient bone volume in this region. Moreover, CHA's signal application can achieve desired clinical effect.

CLINICAL RELEVANCE

This study shows the clinic application of CHA in maxillary sinus augmentation. Compared with popular mixture of autogenous bone and grafting materials, our results show CHA's signal application can achieve ideal osseointegration interface and satisfying clinic effect.

Minimally invasive transcrestal guided sinus lift (TGSL): a clinical prospective proof-of-concept cohort study up to 52 months

PURPOSE

This study describes a new procedure for sinus elevation using computer-guided planning and guided surgical approach through the use of computer-aided design (CAD)/computer-aided manufacturing (CAM)-generated surgical template in combination with expander-condensing osteotomes thus providing a minimally invasive surgical technique.

MATERIALS AND METHODS

Sixty-six consecutive patients were treated with 136 implants placed by transcrestal-guided sinus floor elevation technique and the patients were followed for at least 3 years in function. The drilling protocol is customized based on the bone density of each implant site to achieve an insertion torque ranging between 45 and 55 Ncm. Titanium temporary abutments were connected to the implants with prosthetic screws tightened to 35 Ncm and an acrylic resin provisional restoration was adapted and delivered immediately. Six months after initial loading, a definitive CAD/CAM-generated restoration was delivered. Outcome measurements assessed were implant and prosthesis survival rate, biological or biomechanical complications, marginal bone level changes, total alveolar ridge bone height before and after procedure, periodontal parameters measured as well as patient's perception of pain levels during recovery period.

RESULTS

Mean follow-up was 43.96 (range from 36 to 52) months. Cumulative implant survival rate was 98.53% at 3 years. No biological or mechanical complications were encountered and no prosthetic failures occurred during the entire follow-up period. Mean marginal bone loss (MBL) during the first year of function was 0.33 ± 0.36 mm, while at the 3-year follow-up, the mean MBL was 0.51 ± 0.29 mm. The mean residual bone height of the alveolar crest prior to grafting was of 6.7 ± 1.6 mm (range 5.1-9.2 mm), while, the mean bone height gained was 6.4 ± 1.6 mm (range 3.2-8.1 mm). All patients reported low levels of pain and found to have normal periodontal parameters.

CONCLUSION

This proof-of-concept study suggests that the use of guided surgery to perform transcrestal maxillary sinus floor elevation for alveolar ridge height augmentation is a successful minimally invasive technique for the short- to medium-term follow-up, thus avoiding the extended treatment time and morbidities associated with maxillary sinus floor augmentation.

Crestal sinus lift with sequential drills and simultaneous implant placement in sites with <5 mm of native bone: a multicenter retrospective study

PURPOSE

The aim of this multicenter retrospective clinical study was to evaluate the survival rate of implants placed in the posterior maxilla with a residual bone height of <5 mm.

MATERIALS AND METHODS

One hundred seventeen patients, recruited from 6 different centers, had 134 implants placed below the maxillary sinus. The patient population consisted of 52 men and 65 women ranging in age from 39 to 78 years (mean age, 53.2 years). Sinus lift procedures were performed following a crestal approach using a specific sequence of drills (Cosci's technique). All implants were submerged. Periapical radiographs were obtained with a paralleling technique and were digitized. The pattern of bone remodeling was subsequently evaluated.

RESULTS

The average (±SD) follow-up time was 48.2 months (±29.30 months; range, 24 to 120 months). Of the original 134 implants placed, 5 implants (3.7%) failed. The implant survival rate was 96.3%. The average residual bone height was 3.46 mm (±0.91 mm) at baseline. The average height of the alveolar crest in the treated implant sites was 9.94 ± 2.29 mm. The radiographic bone gain was 6.48 ± 2.38 mm.

CONCLUSION

The investigation suggests that this crestal drill approach can be a successful sinus lifting procedure in a severe atrophic maxilla with <5 mm of crestal bone height.

Osteotome-mediated sinus floor elevation using only platelet-rich fibrin: an early report on 110 patients

PURPOSE

This article describes a technique and reports on the early healing for localized sinus augmentation using a crestal approach in combination with an autologous leukocyte- and platelet-rich fibrin (PRF) concentrate.

MATERIALS

From November 2008 to January 2010, 138 implants were placed in 110 patients using osteotome-mediated sinus floor elevation (OMSFE) with PRF.

RESULTS

The mean residual subantral bone height of the alveolar ridge was 6.6 mm (range, 4-8 mm). The mean increase in the height of implant sites by OMSFE/PRF was 3.4 mm (range, 2.5-5 mm). A variety of 8- to 11.5-mm long (mean length, 10.1 mm) and 3.5- to 6-mm wide (mean width, 4.4 mm) screw-type implants were used. Of the 138 implants that had been placed, 97 have been restored and in function for an average loading time of 5.2 months (range, 1-11 months). The mean healing time for the loaded implants was 4 months until abutment insertion (range, 3-5 months). Three implants failed before loading for an early survival rate of both loaded and unloaded implants of 97.8%.

CONCLUSIONS

Early review of the OMSFE/PRF technique presented for localized sinus floor elevation and implant placement demonstrates a high degree of safety and success at sites with 5- to 8-mm residual subantral bone height.

Evaluation of the effectiveness of a water lift system in the sinus membrane-lifting operation as a sinus surgical instrument

PURPOSE

The effectiveness of a Water Lift System in the sinus membrane-lifting operation was examined. This investigation focused on the capability of this equipment to reduce the risk of Schneiderian membrane perforation.

MATERIALS AND METHODS

A preliminary clinical study on the use of the Water Lift System in sinus membrane elevation to place implants through the sinus floor was conducted. A total of 70 sinus membrane-lifting operations were performed on patients with various bone heights ranging from 1.2 to 9.9 mm (most commonly in the range of 4-6 mm) through the lateral approach (four cases) or the crestal approach (66 cases).

RESULTS

In all of the cases performed using the lateral approach, sinus membrane perforation did not occur. In the 66 cases performed using the crestal approach, Schneiderian membrane tearing occurred in two cases. The membrane tearing occurred during elevation of the Schneiderian membrane but not when a hole was drilled to access the Schneiderian membrane. One case of membrane tearing resulted from previous inflammation in the maxillary sinus, and the other case of membrane tearing was caused by application of excessive hydraulic pressure. In addition, similar outcomes were obtained and no microbial infections were observed in a total of 68 successful cases.

CONCLUSIONS

In this study, the Water Lift System was confirmed to effectively reduce the risk of Schneiderian membrane perforation during the sinus membrane-lifting operation. We conclude that the Water Lift System deserves to be considered as a sinus surgical instrument, which ensures safety in the sinus membrane-lifting operation.