Transcrestal sinus floor elevation: a retrospective study of 46 patients up to 16 years

Risk Factors for Implant Failure Following Transcrestal Sinus-Floor Elevation: A Case Report and Literature Review

Although transcrestal sinus floor elevation (TSFE) is widely used for cases of insufficient residual bone height in the posterior maxilla, few studies focus on the risk factors of early implant failure associated with TSFE procedures. This study aimed to identify and summarize the possible risk factors of implant failure associated with TSFE to ensure a more predictable implant survival rate using TSFE. We report the treatment of a patient with implant failure following TSFE and discuss this case's possible associated risk factors. A standard implant with a diameter of 4.8 mm and length of 10 mm was used after the TSFE procedure. Implant loosening was suddenly observed 6 weeks after the initial surgery. Factors that could result in early implant failure included patient-related risk factors, anatomical factors of the operational area, and operation- and implant-related factors. Within the current study's limitations, the graft material particles between the implant surface and socket could be considered a direct risk factor resulting in implant failure. Therefore, more attention should be paid to socket cleaning during the TSFE procedure, and loose particulate grafting materials should be discouraged. Another significant consideration for implant loss is the possibility of fractures in the buccal or palatal cortical plates during the site preparation and implant insertion. Thus, these factors should be studied further and receive more clinical attention.

Biomechanical analysis of the maxillary sinus floor membrane during internal sinus floor elevation with implants at different angles of the maxillary sinus angles

OBJECTIVE

This study analyzed and compared the biomechanical properties of maxillary sinus floor mucosa with implants at three different maxillary sinus angles during a modified internal sinus floor elevation procedure.

METHODS

3D reconstruction of the implant, maxillary sinus bone, and membrane were performed. The maxillary sinus model was set at three different angles. Two internal maxillary sinus elevation models were established, and finite element analysis was used to simulate the modified maxillary sinus elevation process. The implant was elevated to 10 mm at three maxillary sinus angles when the maxillary sinus floor membrane was separated by 0 and 4 mm. The stress of the maxillary sinus floor membrane was analyzed and compared.

RESULTS

When the maxillary sinus floor membrane was separated by 0 mm and elevated to 10 mm, the peak stress values of the implant on the maxillary sinus floor membrane at three different angles were as follows: maxillary sinus I: 5.14-78.32 MPa; maxillary sinus II: 2.81-73.89 MPa; and maxillary sinus III: 2.82-51.87 MPa. When the maxillary sinus floor membrane was separated by 4 mm and elevated to 10 mm, the corresponding values were as follows: maxillary sinus I: 0.50-7.25 MPa; maxillary sinus II: 0.81-16.55 MPa; and maxillary sinus III: 0.49-22.74 MPa.

CONCLUSION

The risk of sinus floor membrane rupture is greatly reduced after adequate dissection of the maxillary sinus floor membrane when performing modified internal sinus elevation in a narrow maxillary sinus. In a wide maxillary sinus, the risk of rupture or perforation of the wider maxillary sinus floor is reduced, regardless of whether traditional or modified internal sinus elevation is performed at the same height.

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.

A Study of Two Novel Techniques for One-stage Closure of Chronic Oroantral Fistula and Sinus Floor Lift

PURPOSE

This study aimed to compare two novel techniques for chronic oroantral fistula (OAF) closure combined with maxillary sinus floor elevation.

MATERIALS AND METHODS

Ten patients who had implant installation needs but suffered from a chronic OAF were enrolled in the study from January 2016 to June 2021. The technique applied involved OAF closure and simultaneous sinus floor elevation by either a transalveolar or lateral window approach. Bone graft material evaluation results, postoperative clinical symptoms and complications were compared between the two groups. Student's t -test and χ 2 test were used to analyze the results.

RESULTS

In this study, 5 patients with a chronic OAF were treated with the transalveolar approach (group I), and 5 were treated with the lateral window approach (group II). The alveolar bone height was significantly higher in group II than in group I ( P ＜0.001). The pain at 1 day ( P =0.018) and 3 days ( P =0.029) postoperatively and facial swelling at 7 days ( P =0.016) postoperatively were obviously greater in group II than in group I. There were no severe complications in either group.

CONCLUSIONS

The techniques combined OAF closure with sinus lifting to reduce surgical frequency and risks. The transalveolar approach resulted in milder postoperative reactions, but the lateral approach could provide more bone volume.

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.

Tilted Implants and Sinus Floor Elevation Techniques Compared in Posterior Edentulous Maxilla: A Retrospective Clinical Study over Four Years of Follow-Up

The aim of this study was to evaluate the implant survival rate, marginal bone loss, and surgical and prosthetic complications of implants placed through sinus floor elevation and tilted implants engaged in basal bone to bypass the maxillary sinus. Sixty patients were enrolled for this study. According to the residual bone height of the posterior maxilla, the sample was divided into three groups of 20 patients: Group A (lateral sinus floor elevation), Group B (transcrestal sinus floor elevation), and Group C (tilted implants employed to bypass the sinus floor). Follow-up visits were performed one week after surgery, at three and six months, and then once a year for the next 4 years. The outcomes were the implant survival rate, marginal bone loss, and surgical and prosthetic complications. Although Groups A, B, and C demonstrated implant survival rates of 83.3%, 86.7%, and 98.3%, respectively, the statistical analysis showed no statistically significant difference between groups. Statistically significant differences between groups were also not found concerning marginal bone loss, as recorded by intra-oral X-ray measurements during follow-up examinations. Regarding complications, it was not possible to perform a statistical analysis. To reduce possible surgical risks, implant placement in basal bone could be preferred.

Outcomes of implants placed after osteotome sinus floor elevation without bone grafts: a systematic review and meta-analysis of single-arm studies

Background

The aim of this study is to evaluate the implant survival/success rate, gain in alveolar bone height, crestal bone loss, and complications associated with implants placed in the posterior maxilla after osteotome sinus floor elevation without bone substitutes.

Methods

The electronic databases, such as MEDLINE, EMBASE, CENTRAL, and SCOPUS were systematically and manually searched for publications in peer-reviewed journals. The included articles were subjected to qualitative and quantitative analyses, and the meta-analysis was carried out for single-arm studies. Methodological quality assessment was made for all the included studies.

Results

The included studies were of moderate quality, with the overall implant success and survival rates of 98.3% and 97.9% respectively. The most frequent intra-surgical complication was sinus membrane perforation, accounting for 3.08% of the total implants with reported perforations. The overall crestal bone loss in patients with immediate implants placed with OSFE after a 5-year follow-up was 0.957 mm 95%CI (0.538, 1.377).

Conclusion

Within the limitations of this review, it can be concluded that the survival and success rates of implants placed immediately along with OSFE without any bone substitutes are acceptable and show adequate implant stability with less crestal bone loss over 5 years.

Retrospective evaluation about morse taper versus external hexagon implants placed after maxillary sinus lift

BACKGROUND

The objective of this study was to retrospectively evaluate the success and survival rate of implants with different types of prosthetic connections inserted in the posterior maxilla in native bone or in sinuses previously grafted with different biomaterials.

METHODS

A total of 310 implants inserted in 113 patients were evaluated, 87 of which were inserted in association with grafted maxillary sinuses (56 morse taper (MT) implants and 31 external hexagon (EH) implants) in 37 patients, and 223 implants were inserted in native bone areas (112 MT and 111 EH implants) in 76 patients. Peri-implant clinical analyses were performed (bleeding on probing, probing depth, clinical insertion level, peri-implant marginal level, and the presence of mobility or suppuration), and the radiographic bone level was evaluated.

RESULTS

Two implants were lost, yielding a survival rate of 99.35 %. The MT implants had lower probing depths and peri-implant bone levels than the EH implants in both grafted areas and native bone areas (p <0.05). No statistically significant differences in any parameter evaluated were found between implants inserted in native bone and those inserted in grafting areas. EH implants inserted in native bone areas showed higher periimplantitis rates.

CONCLUSIONS

It can be concluded that the MT implants connection reduce periimplant bone loss, but implants inserted in maxillary sinuses previously grafted with osteoconductive biomaterials do not predispose patients to peri-implant bone loss.

Clinical Outcome of Dental Implants after Maxillary Sinus Augmentation with and without Bone Grafting: A Retrospective Evaluation

(1) Background: The purpose of the present study was to retrospectively evaluate and compare the outcome of two sinus augmentation grafting protocols using a xenograft or blood clot alone over a 72-month follow-up. (2) Methods: Patients who received simultaneous lateral sinus floor augmentation and implant placement were included. Subjects were divided into two groups according to the grafting material, namely xenograft or blood clot, and into sub-groups based on the residual alveolar bone height (RABH) below the maxillary sinus, namely 4 to 6 mm or >6 mm. Kaplan-Meier survival estimates were calculated for each material group and for each sub-group at 1, 3, and 6 years. (3) Results: In total, 289 implants inserted in 136 patients with a one-stage procedure were considered. A total of 35 failures were registered. Overall survival rates were 94.2% for xenograft and 85.9% for blood clot alone at 1 year, 91.1% and 81.6% at 3 years, and 91.1% and 78.7% at 6 years. (4) Conclusions: In patients with 4-6 mm RABH, graftless interventions exploiting blood clot alone were not as successful as those using xenograft. When the RABH is low, sinus floor augmentation associated with grafting materials should be preferred whenever possible.

Risk Perception of Septic Shock with Multiple Organ Failure Due to Acute Exacerbation of an Infectious Dental Disease

In general dental conditions such as dental caries and periodontal disease, a combination of adverse conditions can cause potentially life-threatening periodontal abscess. We treated a patient in whom an oral infection developed into septic shock, resulting in patient death. A 78-year-old woman experienced spontaneous pain around a moving tooth. Pus discharge was observed, the area was sterilized, and an analgesic was prescribed. A few days later, the swelling spread to the buccal region leading to difficulty while eating. Upon systemic status and blood examination at our dental hospital, depressed consciousness due to dehydration and septic shock were suspected. Oxygenation and infusion of acetate linger with antibiotics were immediately performed. Furthermore, a blood examination revealed malnutrition and a severe infection; therefore, the patient was transferred to a nearby general hospital. However, the patient died the next day because of advanced disseminated intravascular coagulation and multiple organ failure. When an oral infection is suspected in an elderly patient, antibiotics should be quickly administered, the patient’s local and systemic state should be confirmed, and sterilization should be performed daily. If no improvement is observed, medical attention should be quickly sought.

Metallothionein 3 Promotes Osteoblast Differentiation in C2C12 Cells via Reduction of Oxidative Stress

Metallothioneins (MTs) are intracellular cysteine-rich proteins, and their expressions are enhanced under stress conditions. MTs are recognized as having the ability to regulate redox balance in living organisms; however, their role in regulating osteoblast differentiation is still unclear. In this research, we found that the expression of MT3, one member of the MT protein family, was specifically upregulated in the differentiation process of C2C12 myoblasts treated with bone morphogenetic protein 4 (BMP4). Transfection with MT3-overexpressing plasmids in C2C12 cells enhanced their differentiation to osteoblasts, together with upregulating the protein expression of bone specific transcription factors runt-related gene 2 (Runx2), Osterix, and distal-less homeobox 5 (Dlx5). Additionally, MT3 knockdown performed the opposite. Further studies revealed that overexpression of MT3 decreased reactive oxygen species (ROS) production in C2C12 cells treated with BMP4, and MT3 silencing enhanced ROS production. Treating C2C12 cells with antioxidant N-acetylcysteine also promoted osteoblast differentiation, and upregulated Runx2/Osterix/Dlx5, while ROS generator antimycin A treatment performed the opposite. Finally, antimycin A treatment inhibited osteoblast differentiation and Runx2/Osterix/Dlx5 expression in MT3-overexpressing C2C12 cells. These findings identify the role of MT3 in osteoblast differentiation and indicate that MT3 may have interesting potential in the field of osteogenesis research.

The Influence of Diet on Oxidative Stress and Inflammation Induced by Bacterial Biofilms in the Human Oral Cavity

The article is a concise compendium of knowledge on the etiology of pathogenic microorganisms of all complexes causing oral diseases. The influence of particular components of the diet and the role of oxidative stress in periodontal diseases were described. The study investigated the bacteriostatic effect of the diet of adults in in vivo and in vitro tests on the formation of bacterial biofilms living in the subgingival plaque, causing diseases called periodontitis. If left untreated, periodontitis can damage the gums and alveolar bones. Anaerobic bacteria, called periopathogens or periodontopathogens, play a key role in the etiopathogenesis of periodontitis. The most important periopathogens of the oral microbiota are bacteria of all complexes, including the red complex. The obtained results suggest the possibility of using a specific diet in the prevention and treatment of periodontal diseases-already treated as a disease of civilization. The quoted article is an innovative compilation of knowledge on this subject and it can be a valuable source of knowledge for professional hygienists, dentists, peridontologists, dentistry students and anyone who cares about proper oral hygiene. The obtained results suggest the possibility of using this type of diet in the prophylaxis of the oral cavity in order to avoid periodontitis.

Posterior Mandibular Displacement-A Systematic Review Based on Animal Studies

Treating extreme mandibular growth is challenging. The mandible is pushed backwards to address itsprotrusion. Nevertheless, conclusions after such displacement in animals have been contradictory. The aim of the present review is to present measurable alterations of the mandible and the condyle following retractionin healthy rats or rabbits. PubMed, Scopus and Web of Science were accessed for relevant studies up to October 2020. Eligibility was determined by the PICOS process, while the risk of bias was estimated with SYRCLE's risk of bias tool. Retraction resulted in a more distal molar occlusion and the condyle rested more posteriorly. Mandibular anteroposterior bilateral growth restriction was achieved, the condylar process measured smaller and its angulation increased. The condylar neck thickened, its posterior surface flattened, the coronoid process was measured longer, and enlarged retromolar density was registered. Differences in the ramus height and the intercondylar distance were insignificant. Changes persisted for the period of study and subsequently the mandible resumed its inherited growth pattern. The timing of mandibular shaping and TMJ outcomes might depend on the properties of the applied force. Stability is of concern and well-structured, long-term studies are expected to resolve the issue and further clarify the results of posterior mandibular displacement.

Bioactive Coatings Based on Hydroxyapatite, Kanamycin, and Growth Factor for Biofilm Modulation

The occurrence of opportunistic local infections and improper integration of metallic implants results in severe health conditions. Protective and tunable coatings represent an attractive and challenging selection for improving the metallic devices' biofunctional performances to restore or replace bone tissue. Composite materials based on hydroxyapatite (HAp), Kanamycin (KAN), and fibroblast growth factor 2 (FGF2) are herein proposed as multifunctional coatings for hard tissue implants. The superior cytocompatibility of the obtained composite coatings was evidenced by performing proliferation and morphological assays on osteoblast cell cultures. The addition of FGF2 proved beneficial concerning the metabolic activity, adhesion, and spreading of cells. The KAN-embedded coatings exhibited significant inhibitory effects against bacterial biofilm development for at least two days, the results being superior in the case of Gram-positive pathogens. HAp-based coatings embedded with KAN and FGF2 protein are proposed as multifunctional materials with superior osseointegration potential and the ability to reduce device-associated infections.

Sinus Floor Elevation via an Osteotome Technique without Biomaterials

According to classic Hirschfeld studies, the first teeth to be lost are the first and second maxillary molars. After the teeth are extracted and the alveolar process is developed, the maxillary sinus is reabsorbed and pneumatized with a decrease in bone availability in the posterior sector of the maxilla. This process often creates the need to perform regeneration techniques for the placement of implants in this area due to the low availability of bone. The most frequently used and documented technique for the elevation of the sinus maxillary floor is elevation by the side window, as proposed by Tatum. In 1994, Summers proposed a technique that allowed the elevation of the sinus floor from a crestal access using an instrument called an osteotome, as well as the placement of the implant in the same surgical act. The aimed of the study was to evaluate the survival of 32 implants placed in posterior maxilla with bone availability less than 5 mm performing a sinus lift augmentation technique with osteotome without biomaterials. The results of this study show a survival rate of 100% for 32 implants placed in situations with an initial bone availability of 2 to 5 mm without the use of graft material. The infra-drilling technique used offers an increase in the primary stability of implants that allows adequate osteointegration Implants placed were charged at 12 weeks. In all cases, spontaneous bone formation was observed, even in cases where a positive Valsalva maneuver was observed. This proposed technique reduces treatment time and the need for more invasive maxillary sinus augmentation techniques.

Dental materials implant alloys: a X-ray fluorescence analysis on FDS76®

BACKGROUND

Currently in dentistry, scientific research has been conducted in the study of dental implants. Being able to optimize dental implants, in all its mechanical and biological components, is the main objective of the research. The purpose of this article was to evaluate the structure and the molecular features of dental implant titanium alloy.

METHODS

Two different internal hexagonal connection systems belonging to FDS76^® have been used as sample. Beyond the literature search, fixture and abutment surface through an X-Ray Fluorescence (XRF) method have been analyzed.

RESULTS

The surfaces have achieved an excellent level of quality and low impurity, according to commercial pure titanium alloy.

CONCLUSIONS

This information will surely bring useful information to evaluate the quality of this type of alloy and possibly improve its features.

Multicenter clinical trial on dental implants survival rate: a FDS76® study

BACKGROUND

Implantology, thanks to its predictability in oral rehabilitations, has become a widespread method for rehabilitating edentulous patients, offering excellent patient satisfaction. Improving the quality of oral health, especially if rehabilitation involves minimal short and long-term complications, leads to an improvement in the quality of life of our patients.

METHODS

This clinical study was conducted to evaluate the short and long-term complications (up to 18 months) of implant-prosthetic rehabilitations performed with a new dental implant (FDS76^®, Italy).

RESULTS

The results showed a limited number of complications or implant failures.

CONCLUSIONS

Knowing the latter could certainly help improve both surgical and dental materials performance.

Multicenter clinical trial on dental implants survival rate: a FDS76® study

BACKGROUND

Implantology, thanks to its predictability in oral rehabilitations, has become a widespread method for rehabilitating edentulous patients, offering excellent patient satisfaction. Improving the quality of oral health, especially if rehabilitation involves minimal short and long-term complications, leads to an improvement in the quality of life of our patients.

METHODS

This clinical study was conducted to evaluate the short and long-term complications (up to 18 months) of implant-prosthetic rehabilitations performed with a new dental implant (FDS76^®, Italy).

RESULTS

The results showed a limited number of complications or implant failures.

CONCLUSIONS

Knowing the latter could certainly help improve both surgical and dental materials performance.

Distal Displacement of Maxillary Sinus Anterior Wall Versus Conventional Sinus Lift with Lateral Access: A 3-Year Retrospective Computerized Tomography Study

Background: The present study is designed to compare the outcomes of two sinus augmentation procedures: distal displacement of the anterior wall versus standard sinus lifting and grafting with a lateral window approach. Methods: In the displacement group, a localized surgical fracture of the sinus floor achieved through an electromagnetic device results in the distal displacement of the anterior wall. In the filling group, sinus lifting (with lateral access) and grafting with particulate xenogeneic bone substitute was performed. Bone volume beneath the maxillary sinus was investigated with computerized tomography after baseline and postoperative data superimposition. Clinical and radiological outcomes over three years had been evaluated. Results: Forty-three dental implants were selected. The two sinus lift procedures significantly increased the bone volume (p-value ≤ 0.0017) in the displacement group from 1.17 ± 0.34 to 1.53 ± 0.39 cc, with a final bone gain of +0.36 ± 0.17 cc, and in the filling group from 1.24 ± 0.41 to 1.94 ± 0.68 cc, with a bone augmentation of +0.71 ± 0.31 cc. No events of dental implant bulging into the maxillary sinus occurred. Two implants failed early on in the filling group, attesting the 3-year survival rate of 92.6% (CI95%: 82.7–100%). Marginal bone loss at the distal aspect was 1.66 ± 0.72 and 1.25 ± 0.78 mm, respectively, for the displacement and filling groups, with a significant difference (p-value = 0.0497). Conclusion: Results showed a significant and effective bone gain around dental implants at a 3-year survey for both sinus augmented by backward displacement of the anterior wall (+34%) and sinus lifting and grafting with a lateral window approach (+57%).

Lateral Window Design for Maxillary Sinus Graft Based on the Implant Position

The purpose of this study was to devise a classification and lateral window design method based on implants and to evaluate whether these classifications and methods are applicable to clinical practice. When applying the maxillary sinus elevation technique using the lateral window, possible situations were classified into four: (A) two or more sites for implants are required for maxillary sinus augmentation, (B) a single implant is required when there are no adjacent teeth, (C) a single implant is required when one adjacent tooth is present at the mesial or distal area, and (D) a single implant is required when both mesial and distal adjacent teeth are present. In order to verify whether this classification can be used in all situations, 76 patients who underwent maxillary sinus elevation with a lateral window were selected and investigated. Of them, 47 (62%) were included in Group A, 9 (12%) in Group B, 8 (11%) in Group C, and 12 (15%) in Group D. Lateral window designing in the lateral approach of sinus augmentation can be classified into four clinical situations. There were no unclassified cases. This classification and window positioning method can be applied to most cases.

A Simple and Safe Approach for Maxillary Sinus Augmentation with the Advanced Surgical Guide

Objective: The development of digital dentistry has contributed to the astonishing advancement of implant dentistry. Furthermore, digital technology is expected to be applied extensively to sinus augmentation, which is an advanced technique for implant surgery. This study introduces a simple method for a safer and more precise lateral window opening for sinus augmentation using a navigation program. Methods: Five eligible patients with residual alveolar bone of 4 mm or less are presented, requiring lateral approach for sinus augmentation. Navigation system was opted for the sinus lift with simultaneous implant placement. Virtual planning started with establishing the adequate position of the lateral window based on the radiographic images and the scanned file of the dentition. The position of the window was indicated on the guide within the program. Afterwards, the virtually designed surgical guide was fabricated either with 3D printer or milling machine for the actual surgery. Results: All the patients who underwent surgery with the surgical guide showed no sign of clinical complications including pain, swelling, nausea, epistaxis, or early loss of the implants. Results of radiographic evaluation also showed adequate placement of the implants in a pre-planned position, and the sinus window was also formed in the desired location. Conclusion: Lateral window opening combined with digital navigation system is believed to be a promising technique for a more precise as well as safer sinus augmentation.

Therapeutic outcomes of non-grafted and platelet concentrations-grafted transcrestal maxillary sinus elevation (TSFE): a systematic review and meta-analysis

To evaluate and compare the stability, quantity and quality of bone augmentation at maxillary sinus elevation sites by non-grafted transcrestal sinus floor elevation (TSFE) and platelet concentration grafted transcrestal sinus floor elevation (PC-TSFE). A complete literature search was performed up to April 2019. Clinical controlled trials, retrospective cohort studies, and prospective cohort studies were selected based on inclusion criteria. The clinical outcomes were implant survival rate (ISR), marginal/crestal bone loss (MBL/CBL) and endo-sinus bone gain (ESBG). Meta‐analysis was conducted on these 1-year based values. Furthermore, another meta-analysis on 1-year ISR value was conducted among studies with different residual bone heights (RBH) within the non-grafted TSFE group. A total of 18 studies were included: 13 in TSFE group and 5 in PC-TSFE group. No significant differences were displayed between the 1-year ISR of TSFE (97%, 95%CI = 0.96–0.99) and PC-TSFE group (99%, 95%CI = 0.97–1.00). Among the various studies with different RBH within TSFE group, no significant differences in 1-year ISR were displayed. The 1-year MBL/CBL value of PC-TSFE group (0.73 mm, 95%CI = 0.43–1.13 mm) did not show significant difference as compared to TSFE group (0.60 mm, 95%CI = 0.10–1.10 mm). Furthermore, no significant enhancement was observed on 1-year ESBG value on PC-TSFE group (3.51 mm, 95%CI = 2.31–4.71 mm) in comparison with the TSFE group (2.87 mm, 95%CI = 2.18m–3.55 mm). Grafting platelet concentrations around dental implants at TSFE sites did not significantly enhance the adjacent bone regeneration. Moreover, TSFE was shown to be a reliable therapeutic option for implant sites that need simultaneous maxillary sinus augmentation, even under limited RBH.

Prospective, Clinical Pilot Study with Eleven 4-Mm Extra-Short Implants Splinted to Longer Implants for Posterior Maxilla Rehabilitation

In many clinical situations, rehabilitation with implants in the posterior maxillary region is complicated by limited bone availability. In this context, the use of 4 mm long implants (known as extra-short implants) may be used thanks to the concept of osseointegration enhancement. It has been demonstrated that short implants offer an alternative to the regeneration procedures involved in placing longer implants in areas where bone height is compromised. This prospective pilot study tested a treatment protocol in which 11 extra-short (4 mm) implants were splinted to 11 mesially placed longer (8 mm) implants in the posterior maxillary regions of partially edentulous patients, without using supplementary bone regeneration procedures. Eleven patients were included in this single cohort study. The clinical performance of the extra-short implants was assessed during a two-year follow-up period, obtaining a 100% survival rate and mean bone loss of 0.3 mm. Implant stability measured by resonance frequency analysis (RFA) at the time of placement was 54.9 ± 4.9, increasing to 77.0 ± 2.6 at 24 months. The study demonstrated the gradual consolidation of osseointegration in bone of less-than-ideal quality in the posterior maxillary region. The results obtained show that a partially edentulous maxilla with reduced bone height may be rehabilitated by using an extra-short implant splinted to a mesial implant of 8mm length or longer. Despite the small sample size, this pilot study observed that extra-short implants achieved adequate bone stability and clinical performance after a 24-month follow-up.

Maxillary Antrostomy Patency Following Intraoperative Use of Spray Cryotherapy

Objectives/Hypothesis: Stenosis of the middle meatus antrostomy (MMA) represents a major cause of recurrent disease following endoscopic sinus surgery (ESS). Various strategies have been developed to prevent the occurrence of MMA stenosis. The aim of the present study was to evaluate the effects of spray cryotherapy (SC) on nasal wound healing following ESS. Methods: This is a prospective within-subject, randomized, and controlled trial. Twenty-six patients submitted to bilateral ESS with chronic rhinosinusitis without polyps were included. Following surgery, patients were randomized to receive SC on one side and saline contralaterally. Outcomes were represented by MMA diameter and area, histology of nasal mucosa, and nasal symptoms. Variables were assessed at 3 and 12 months postoperatively. Results: The MMA size in the SC group at 3 and 12 months (area-0.578 ± 0.1025 cm², diameter-0.645 ± 0.1024 cm; 0.605 ± 0.1891 cm², 0.624 ± 0.0961 cm, respectively) was significantly larger (p = 0.000) than in the control group. Histology established that cell infiltration, goblet cells, edema, and epithelial hyperplasia were prominent and persistent in the control side compared to the SC side. Nasal obstruction and discharge were significantly improved in the SC group compared to the control group. Conclusion: SC is a promising therapy following ESS, since it precludes MMA stenosis and decreases inflammation, edema, and goblet cell hyperplasia.

Conventional versus Digital Impressions for Full Arch Screw-Retained Maxillary Rehabilitations: A Randomized Clinical Trial

Background: The objective of this study was to compare conventional versus digital impressions for Full-Arch maxillary rehabilitations. Methods: Patients selected for this study were treated with full-arch screw-retained rehabilitations supported by six immediately loaded dental implants. Patients have been scheduled randomly into control (conventional impression group, CIG) and test (digital impression group, DIG) groups respectively for a fully conventional workflow and a fully digital workflow. In both groups, within 24 h, temporary prostheses were delivered. Four months after the implant positioning, the two groups dealt with the fabrication of definitive restorations: conventional pick-up was performed in the control group, and definitive digital impressions were carried out in the test group. The time involved following these two procedures was recorded. Patients underwent intraoral digital radiographs to evaluate the accuracy of the framework-implant connection, check for the presence of voids at the bar-implant connection and measure bone level. Criteria used to assess success at the prosthetic level were the occurrence of prosthetic maintenance, the absence of fractures of the acrylic resin superstructure and voids. Results: A total of 50 patients received immediately loaded prostheses supported by six implants (total 300 implants). A fixture and prosthetic survival rate of 100% was observed. All digital X-ray examinations revealed a bar-implant connection accuracy and no voids. Differences that were not statistically significant (p > 0.05) in marginal bone loss were found between control and test groups. Significantly less time was spent to perform digital impression procedure (p < 0.05). Conclusions: Clinical and radiological results of the test group advocate a satisfactory accuracy and predictability of the intraoral scanner (IOS) to be a reliable alternative in clinical practice for implant full-arch rehabilitations and suggest fabrication of definitive restorations with a successful marginal fit precision.

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%.

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.

Clinical and Radiological Outcomes of Implants in Osteotome Sinus Floor Elevation with and without Grafting: A Systematic Review and a Meta-Analysis

PURPOSE

To systematically appraise the clinical and radiological outcomes after osteotome sinus floor elevation (OSFE) with or without grafting in the published dental literature.

METHODS

An electronic search was conducted using PubMed, Web of Science, and the Cochrane Central Register of Controlled Trial to identify studies after OSFE from January 1, 1994 to August 30, 2015. The primary outcome was the implant survival rates after OSFE with and without grafting materials.

RESULTS

After search and evaluation of the literature according to the inclusion criteria, 7 studies were included in the review. The random-effect model meta-analysis based on 463 implants in patients without grafting and 415 implants in patients with grafting showed that the risk ratio difference of survival rates was 1.010 (95%CI 0.910, 1.120), which did not reach statistical significance (p = 0.99). The membrane perforation rates ranged from 0% to 10.80%. No significant difference of crestal bone loss was reported between graft and nongraft groups.

CONCLUSIONS

Based on currently available evidence, OSFE techniques with and without grafting were both predictable in the short term. In addition, survival rates of dental implants in OSFE with or without grafting did not show any significant difference in the short term.

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.

Comparison of piezosurgery and conventional rotative instruments in direct sinus lifting

OBJECTIVES

The purpose of this study was to compare the intraoperative and postoperative effects of Piezosurgery and conventional rotative instruments in direct sinus lifting procedure.

PATIENTS AND METHODS

Twenty-three patients requiring direct sinus lifting were enrolled. The osteotomy and sinus membrane elevation were performed either with Piezosurgery tips or rotative diamond burs and manual membrane elevators. Time elapsed between bony window opening and completion of membrane elevation (duration), incidence of membrane perforation, visibility of the operation site, postoperative pain, swelling, sleeping, eating, phonetics, daily routine, and missed work as well as patient's expectation before and experience after the operation were evaluated.

RESULTS

There was no significant difference between Piezosurgery and conventional groups regarding incidence of membrane perforation, duration, and operation site visibility as well as patient's expectation before and experience after the operation (P > 0.05). However, there were significantly more pain and swelling in the conventional group compared with the Piezosurgery group (P ≤ 0.05).

CONCLUSION

Sinus lifting procedure performed with Piezosurgery causes less pain and swelling postoperatively compared with conventional technique. Patients' daily life activities and experience about the operation are not affected from the surgical technique.

Anatomical preconditions for the palatal sinus floor augmentation—A three-dimensional feasibility study

OBJECTIVE

The aim of this study was to evaluate the anatomical feasibility of palatal sinus floor augmentation.

MATERIAL AND METHODS

In 100 men and 100 women, both sinuses were analyzed using computed tomography. The patients were divided into four anatomical groups according to the remaining alveolar bone height: group 1 (0 ≤ × < 4), group 2 (4 ≤ × < 8), group 3 (8 ≤ × < 12), and group 4 (≥12).

RESULTS

The 400 maxillary sinuses consisted of 23.5% (n = 94) group 1, 42.75% (n = 171) group 2, 23.5% (n = 98) group 3, and 9.25% (n = 37) group 4 sinuses. Optimal anatomical preconditions for palatal sinus floor augmentations (i.e., ≥5 mm height and <5 mm thickness of the window lid) were found in 93.6% of group 1 sinuses, 73.7% of group 2 sinuses, 23.5% of group 3 sinuses, and 5.4% of group 4 sinuses.

CONCLUSION

The palatal approach is feasible in 93.6% of patients with remnant alveolar height of up to 4 mm. Limitations are alveolar heights of ≤5 mm as well as great palatal thickness and thus limited dimensions for a possible palatal window.

Indirect sinus lift without bone graft material: Systematic review and meta-analysis

A systematic literature review and a meta-analysis of indirect sinus lift without the use of bone graft material was performed. A PubMed search was made from January 2005 to January 2012 with keywords: "sinus lift", "osteotome", "graft" and "maxillary sinus elevation". The inclusion criteria were: maxillary sinus lift technique with osteotomes with a minimum follow-up period of 5 months after surgery without bone graft material. 11 articles were included. The mean gain in residual crestal bone height after maxillary sinus lift without bone graft material was 3,43 mm ± 0,09 (2,5 mm - 4,4 mm). The survival rate ranged from 94% to 100%. Placement of implants with sinus lift without bone graft material, is a valid surgical technique to gain residual crestal height and placed implants in an atrophic posterior maxillary with a crestal height from 5 to 9 mm. Key words:Sinus lift, osteotome, graft, maxillary sinus elevation.

Survival rate of Astra Tech implants with maxillary sinus lift

Objectives

The aim of this study was to retrospectively evaluate the clinical survival rate of Astra Tech implants in the maxillary molar region performed with sinus lift and bone graft.

Materials and Methods

Ninety-nine Astra Tech implants (Osseospeed) placed in the maxillary molar region using sinus lift from September 2009 to February 2012 were selected with a minimum follow-up period of 1 year. The height of alveolar bone, sinus approach technique, bone material and implant survival rate were evaluated.

Results

Of the 99 implants, the survival rate was 90.9%; 8 implants failed within 1 year after implant placement, and 1 implant failed 1 year after implant loading. All failed implants were placed with sinus lift simultaneously. The average height of alveolar bone before implant placement was 6.9 mm, while the height of alveolar bone of failed implants was 2.1 mm, on average.

Conclusion

Astra Tech implants placed in the maxillary molar region had generally good survival rates, but the relationship between reduced pre-implant alveolar bone height and implant failure requires further attention.

Osteotome-Mediated Sinus Lift without Grafting Material: A Review of Literature and a Technique Proposal

Implant rehabilitation of the edentulous posterior maxilla may be a challenging procedure in the presence of insufficient bone volume for implant placement. Maxillary sinus augmentation with or without using grafting materials aims to provide adequate bone volume. The aim of the present study was to systematically review the existing literature on transalveolar maxillary sinus augmentation without grafting materials and to propose and describe an osteotome-mediated approach in postextraction sites in combination with platelet derivative. The systematic review showed that high implant survival rate (more than 96% after 5 years) can be achieved even without grafting the site, with a low rate of complications. Available alveolar bone height before surgery was not correlated to survival rate. In the described case report, three implants were placed in posterior maxilla after extraction of two teeth. An osteotome-mediated sinus lifting technique was performed with the use of platelet derivative (PRGF); a synthetic bone substitute was used to fill the gaps between implant and socket walls. No complications occurred, and implants were successfully in site after 1 year from prosthetic loading. The presented technique might represent a viable alternative for the treatment of edentulous posterior maxilla with atrophy of the alveolar bone though it needs to be validated by studies with a large sample size.