Implant survival rates after maxillary sinus augmentation

The use of a biphasic calcium phosphate in a maxillary sinus floor elevation procedure: a clinical, radiological, histological, and histomorphometric evaluation with 9- and 12-month healing times

Background

This study evaluates the clinical, radiological, histological, and histomorphometric aspects of a fully synthetic biphasic calcium phosphate (BCP) (60% hydroxyapatite and 40% ß-tricalcium phosphate), used in a human maxillary sinus floor elevation (MSFE) procedure with 9- and 12-month healing time.

Methods

A unilateral MSFE procedure, using 100% BCP, was performed in two series of five patients with healing times of 9 and 12 months respectively. Clinical and radiological parameters were measured up to 5 years postoperatively. Biopsy retrieval was carried out during dental implants placement. Histology and histomorphometry were performed on 5-μm sections of undecalcified bone biopsies.

Results

The MSFE procedure with BCP showed uneventful healing in all cases. All dental implants appeared to be well osseointegrated after 3 months. Radiological evaluation showed less than 1 mm tissue height loss from MSFE to the 5-year follow-up examination. No signs of inflammation were detected on histological examination. Newly formed mineralized tissue was found cranially from the native bone. The BCP particles were surrounded by connective tissue, osteoid islands, and newly formed bone. Mineralized bone tissue was in intimate contact with the BCP particles. After 12 months, remnants of BCP were still present. The newly formed bone had a trabecular structure. Bone maturation was demonstrated by the presence of lamellar bone. Histomorphometric analysis showed at 9 and 12 months respectively an average vital bone volume/total volume of 35.2 and 28.2%, bone surface/total volume of 4.2 mm²/mm³ and 8.3 mm²/mm³, trabecular thickness of 224.7 and 66.7 μm, osteoid volume/bone volume of 8.8 and 3.4%, osteoid surface/bone surface (OS/BS) of 42.4 and 8.2%, and osteoid thickness of 93.9 and 13.6 μm.

Conclusions

MFSE with BCP resulted in new bone formation within the augmented sinus floor and allowed the osseointegration of dental implants in both groups. From a histological and histomorphometric perspective, a 9-month healing time for this type of BCP may be the optimal time for placement of dental implants.

Immediate full-arch rehabilitation of the severely atrophic maxilla supported by zygomatic implants: a prospective clinical study with minimum follow-up of 6 years

The aim of this study was to evaluate the outcomes of immediate full-arch prostheses supported by zygomatic implants alone or in combination with standard fixtures after a minimum of 6 years of loading. From October 2008 to April 2010, 15 patients with severely atrophic maxillae were treated using four zygomatic implants or two zygomatic implants in conjunction with two conventional fixtures. All subjects received a fixed screw-retained prosthesis within 3hours of surgery, while the final restoration was delivered after 6 months. Follow-up examinations were scheduled to evaluate zygomatic implant survival, conventional dental implant success, prosthetic success, plaque and bleeding scores, marginal bone loss for conventional dental implants, and patient satisfaction. Forty-two zygomatic fixtures and 18 standard implants were placed. Patients were followed up for a minimum of 79 months (range 79-97 months, average 90.61 months). No implant was lost, leading to implant and prosthetic survival rates of 100%. Bone loss for conventional implants averaged 1.39±0.10mm after 6 years of function, leading to a 100% implant success rate. High levels of patient satisfaction were recorded. These medium-term results indicate that immediate full-arch rehabilitation supported by zygomatic implants could be considered a viable treatment modality for the severely atrophic maxilla.

Maxillary Sinus Grafting With Biphasic Bone Ceramic or Autogenous Bone: Clinical, Histologic, and Histomorphometric Results From a Randomized Controlled Clinical Trial

PURPOSE

The present, randomized, controlled clinical trial compared the histologic and histomorphometric results from maxillary sinus augmentation with either biphasic calcium phosphate (BCP) (60% hydroxyapatite and 40% β-tricalcium phosphate) or autogenous bone (AB) as bone-grafting materials.

MATERIAL AND METHODS

Ten patients received bilateral sinus elevation surgery with intraoral AB chips (control group) on one side and BCP (test group) on the contralateral side. After a healing period of 6 to 8 months, implant sites were created and trephine cores were harvested for histological and histomorphometric analysis of the grafted areas.

RESULTS

The histological examination of biopsies showed BCP particles interconnected by bridges of a vital newly formed bone. Histomorphometry demonstrated that the amount of newly formed bone in the control group (36.8%) was significantly greater than that in the BCP (28.2%) group (P = 0.0032). BCP and AB cores revealed an average of residual graft particles of 32.9% and 4.8%, respectively. The average percentage of soft tissue components was 38.9% in the BCP cores and 58.4% in the AB cores.

CONCLUSIONS

Based on our findings, the amount of vital bone formation was significantly higher for AB than that for BCP. However, BCP seemed to be a biocompatible and osteoconductive material that can be used with success as a bone substitute in maxillary sinus procedures.

Maxillary Sinus Floor Augmentation Using Biphasic Calcium Phosphate and a Hydrogel Polyethylene Glycol Covering Membrane: An Histological and Histomorphometric Evaluation

PURPOSE

Maxillary sinus floor augmentation with a lateral approach is usually performed using a bone substitute covered with standard collagen or a synthetic barrier membrane to prevent soft tissue ingrowth within the bone graft. The purpose of this case series was to evaluate a polyethylene glycol (PEG) membrane with a hydrogel consistency, used to protect the lateral sinus anstrotomy, by analyzing the histological quality and histomorphometric quantity of newly formed bone (NB) in a maxillary sinus graft using biphasic calcium phosphate (BCP).

MATERIALS AND METHODS

Fifteen sinuses were grafted from 12 patients. Six months after the maxillary sinus floor augmentation, bone biopsies were harvested from 7 patients during the implant placement second-step surgery.

RESULTS

The histomorphometric evaluation of the 7 grafted sinuses showed mean values of 27.4 ± 4.6% for NB, 26.9 ± 5.4% for remaining BCP particles, and 45.7 ± 6.0% for connective tissue/bone marrow. No implant failure was observed in the 14- to 45-month follow-up period after maxillary sinus floor augmentation procedure and in the 8- to 39-month follow-up period after implant loading.

CONCLUSION

The use of a hydrogel PEG membrane to protect BCP proved to be a valuable grafting procedure to enhance the vital bone formation in the maxillary sinus floor augmentation procedure.

Maxillary Sinus Floor Elevation Using Platelet-Rich Plasma Combined With Either Biphasic Calcium Phosphate or Deproteinized Bovine Bone

PURPOSE

Maxillary sinus floor elevation procedure has the objective of augmenting available bone in atrophic posterior maxilla to allow dental implants placement. The main aim of this prospective study was to evaluate clinically and histomorphometrically the performance of biphasic calcium phosphate (BCP) used in conjunction with platelet-rich plasma (PRP) compared with demineralized bovine bone matrix (DBBM) and PRP in sinus floor elevation surgery.

MATERIALS AND METHODS

Patients candidate to sinus floor elevation were treated using either BCP and PRP or DBBM and PRP. Biopsies were retrieved using trephine bur during implant placement surgery 6 months after grafting. Clinical success of implants was evaluated 1 year after prosthesis delivery. Histomorphometric analysis was performed assessing the relative volume of newly formed bone.

RESULTS

A total of 20 patients were recruited, and 20 sinus augmentation procedures were performed, 10 for each group. A total of 42 implants were placed. One year after prosthetic loading a 100% implant survival rate was reported in both groups. Histomorphometric analysis revealed that the mean amount of new bone formation was 18.6 ± 3.3% in BCP group and it was 21.9 ± 4.9% in DBBM group, without statistically significant difference. In BCP group a greater amount of collagen type I was found with respect to DBBM group.

CONCLUSIONS

Both grafting materials led to an excellent performance regarding implant survival rate after 1 year follow-up, without any significant adverse sequelae. A similar capability of inducing new bone formation was observed in both groups, even though the higher quantity of collagen type I in BCP group may suggest a greater potential for bone formation over time as compared with DBBM.

Preoperative chronic sinusitis as significant cause of postoperative infection and implant loss after sinus augmentation from a lateral approach

OBJECTIVES

Among intra/postoperative complications of sinus augmentation from a lateral approach, postoperative infection and implant loss are particularly important because they have irreversible consequences. The purpose of this study was to determine the causes of postoperative infection and implant loss after a lateral approach and to determine the appropriate prophylaxis and therapy.

MATERIALS AND METHODS

In total, 109 patients (121 sinuses, 252 implants) were included in this study. The correlation between postoperative infection and implant loss and clinical variables was assessed using logistic regression analyses.

RESULTS

Postoperative infection and implant loss occurred in 8/121 sinuses (6.6%). Infection had the strongest correlation to preoperative chronic sinusitis (p = 0.007), followed by timing of implant insertion. Implant loss had the strongest correlation to preoperative chronic sinusitis (p = 0.007), followed by sex, diabetes, postoperative use of dentures, and intraoperative perforation of the sinus membrane.

CONCLUSIONS

Preoperative chronic sinusitis could be a significant cause of postoperative infection and implant loss when using sinus augmentation from a lateral approach. For appropriate prophylaxis and therapy, it is necessary to diagnose the presence of chronic sinusitis that should be treated with proper methods prior to sinus augmentation.

Effects of BMP-2 Delivery in Calcium Phosphate Bone Graft Materials with Different Compositions on Bone Regeneration

This study was undertaken to investigate the effect of loading rhBMP-2 onto biphasic calcium phosphate (BCP) and calcium pyrophosphate (CPP) on bone regeneration, and to examine the efficacies of BCP and CPP as rhBMP-2 carriers. Specimens were divided into the BCP, CPP, BCP/BMP, and CPP/BMP groups; BCP and CPP were in granules and not coated with rhBMP-2. BCP/BMP and CPP/BMP were prepared as discs, which were treated with rhBMP-2 and collagen. Physical and biological features were investigated using in-vitro and in-vivo tests. New bone area percentages (%) in the BCP/BMP and CPP/BMP groups were significantly greater than in the BCP and CPP groups. At weeks 4 and 8 post-implantation, CPP/BMP showed the most new bone growth. Within the limitations of this study, treatment of BCP and CPP with rhBMP-2 significantly enhanced bone regeneration. CPP was found to be a suitable carrier for rhBMP-2.

Multidisciplinary Management of Candidates for Maxillary Sinus Augmentation by a Surgeon and ENT Specialist

Maxillary sinus augmentation has been shown to be a predictable treatment option for placing dental implants in areas of posterior maxilla with lack of sufficient residual alveolar bone height.¹ The transalveolar (crestal) and the lateral window are the main techniques for the maxillary sinus augmentation with the goal of creating a space beneath the Schneiderian membrane in which to place various grafting materials in order to increase alveolar bone height.

Histomorphometric results of different grafting materials and effect of healing time on bone maturation after sinus floor augmentation: a systematic review and meta-analysis

The aim of this systematic review was to evaluate histomorphometric variables, the amount of new bone (NB), residual graft (RG) particles and soft tissue (ST), related to various grafting materials and assess the effect of graft healing time on different histomorphometric outcomes. Studies that were published before October 2015 were electronically and manually searched in three databases. We included human studies that reported the amount of NB, RG and ST in the biopsies taken from the grafted sinuses. Based on the applied grafting materials, extracted data were categorized into different groups. Furthermore, extracted data were classified into three groups based on healing time: (i) ≤ 4.5 mo; (ii) 4.5-9 mo; and (iii) ≥ 9-13.5 mo. The search provided 791 titles. Full text analysis was performed for 258 articles resulting in 136 studies that met the inclusion criteria. Autogenous bone (AB) resulted in the highest amount of NB and lowest amount of RG compared to other grafting materials. Based on this meta-analysis, a significant difference was noticed in the amount of NB formation in grafts with a healing time of > 4.5 mo when compared to the grafts with less healing time. However, when comparing biopsies taken at 4.5-9 mo of healing (average = 6.22 mo) to the ones taken at ≥ 9-13.5 mo (average = 10.36 mo), no significant difference was noticed in the amount of NB formation of various grafts except allografts that resulted in a significantly higher percentage of NB at 9.5 mo of healing. Based on histomorphometric analysis, AB results in the highest amount of NB formation in comparison to the other grafting materials. Bone substitute materials (allografts, alloplastic materials and xenografts) seem to be good alternatives to autogenous bone and can be considered as grafting materials to avoid disadvantages related to AB, including morbidity rate, limited availability and high volumetric change. Combining AB with alloplastic materials and xenografts brings no significant advantages regarding NB formation.

Sinus lift: 3 years follow up comparing autogenous bone block versus autogenous particulated grafts

Background/purpose

The aim of this prospective randomized controlled clinical trial was to compare vertical bone gain and bone resorption after sinus graft procedures performed either with particulate or with autogenous bone block.

Material and methods

Forty-one patients underwent sinus graft procedures with autogenous bone. They were randomly assigned to one group. The first group of 22 patients was treated with autogenous bone block with or without particulated bone, while in the second group of 19 patients sinus floor elevation was performed only with particulated autogenous bone. Linear measurements were recorded before surgery with a computed tomography scan at surgery and at 36 months after sinus lift grafting with a second computed tomography scan. To detect statistical differences Student t test was applied. Differences were considered significant if P values were < 0.05.

Results

There was a statistically significant difference in bone gain for the group treated with bone block grafts.

Conclusion

As a general clinical guideline the clinician should prefer, wherever feasible, en-block bone grafts for sinus floor augmentation procedures.

Radiographic Evaluation of Maxillary Sinus Lateral Wall and Posterior Superior Alveolar Artery Anatomy: A Cone-Beam Computed Tomographic Study

OBJECTIVE

The purpose of the current study is to assess the thickness of the maxillary sinus lateral wall in dentate and edentulous patients using cone beam computed tomography (CBCT). This study also provides information about the diameter, prevalence, and course of the posterior superior alveolar artery (PSAA), and its relation to the maxillary sinus floor.

MATERIALS AND METHODS

Four hundred and thirty CBCT scans of the maxillofacial complex (860 maxillary sinuses) were reviewed. Measurements of the lateral wall of the maxillary sinus and PSAA were performed on the CBCT images.

RESULTS

Statistical analysis showed that dental status (edentulous, non-edentulous) of the patients had no significant effect on the lateral wall thickness. The mean thickness of the lateral wall of the maxillary sinus was 1.21 ± 1.07 mm at the second molar (M2), 1.98 ± 1.87 mm at the first molar (M1), 2.02 ± 1.53 mm at the second premolar (P2) and 2.16 ± 1.25 mm at the first premolar (P1). There was statistically significant difference between the left and right sides of the maxillary sinus only at P2 (p =.043). Detection rate of the PSAA on CBCT was reported as 60.58%. The mean diameter of the artery was 1.17 mm (range 0.4-2.8 mm). There was no significant correlation between age and the size of the PSAA. The most frequent path of the PSAA was intraosseous (69.6%), followed by intrasinusal (24.3%) and superficial (6.1%). The overall mean distance of the PSAA from the floor of the maxillary sinus is 8.16 mm.

CONCLUSIONS

The results from this study suggest that using CBCT prior to the surgery provides valuable diagnostic information. However, undetected intraosseous canal in CBCT does not exclude its existence. Alteration in the lateral window design and the use of piezoelectric instruments are recommended if intraoperative complications are expected.

A comprehensive clinical review of maxillary sinus floor elevation: anatomy, techniques, biomaterials and complications

Several systematic reviews have shown that maxillary sinus augmentation is a predictable and effective procedure for augmentation of an atrophic posterior maxilla. However, we know of no reviews that have covered all the clinical aspects. We searched the PubMed, EMBASE, Cinhal, and Cochrane databases up to January 2015 to select relevant studies that cover the different objectives of this review, including the anatomy of the maxillary sinus, surgical techniques, biomaterials used in the sinus augmentation, and potential complications.

Chemical and Topographic Analysis of Eight commercially Available Dental Implants

BACKGROUND

Surface characterization of dental implants allows us to better understand the effects of the implant on the host biological response. In this study, we analyzed and compared these characteristics among implants commercially available in South Africa.

MATERIALS AND METHODS

Eight implants from different manufacturers were chosen for analysis (Touareg, ICE, (R)Evolutions, Uniti, AnyRidge, MIS, Ivory-QSI, Southern), using scanning electron microscopy (SEM), interferometry, and energy dispersive X-ray spectroscopy to study the surface chemical composition and morphology.

RESULTS

The results indicate that variations in manufacturer processes result in implant surfaces that are distinctly different from one another. Most implants presented a moderately rough surface with sandblasted-only implant surfaces having a lower mean value of Sa when compared with sandblasted and acid-etched surfaces. Carbon contamination was detected on all the implants and that of aluminum on five implant surfaces. Ca and P were detected on the surface of Touareg implants, indicating the manufacturer's attempt to enhance osseointegration.

CONCLUSION

The surface of the implants showed a range of chemical, physical properties, and surface topographies.

CLINICAL SIGNIFICANCE

The results indicate that implant surface treatment is not standardized. This may have clinical implications. Further clinical research is required.

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

Background

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

Material and Methods

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

Results

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

Conclusions

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

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

The effect of hydrothermal spark discharge anodization in the early integration of implants in sheep sinuses

OBJECTIVES

Spark discharge anodic oxidation forms a porous oxide film on titanium implant surfaces, which may increase surface roughness and enhance early osseointegration. This study aimed to clinically and histomorphometric compare commercially-available sandblasted (RBM) implants, treated with hydrothermal anodization and placed into an animal maxillary sinus model.

MATERIALS AND METHODS

Thirty 3.75 mm × 8.5 mm threaded titanium implants were placed into the maxillary sinuses of 10 sheep via an external approach, with three test groups and 10 implants per group: right side, Control = CP-titanium with RBM surface, Test group 1 = CP-titanium with RBM + anodized surface; left side, Test group 2 = Ti-6Al-7Nb with RBM + anodized surface. Schneiderian membranes were elevated but not bone grafted. Resonant frequency analysis (RFA) was measured at surgery. Animals were sacrificed after 1 month unloaded healing. Resin-embedded undemineralized ground-sections were digitised, and mean bone-implant contact (% BIC) was measured bilaterally for the best-three consecutive threads.

RESULTS

Seven of 30 implants showed signs of failure. RFA was low at placement but did not differ between the groups (group mean ISQ values ranged from 23 to 35; χ(2)  = 0.37). RFA was not repeated at sacrifice due to implant instability. Histomorphometric analysis showed % BIC was highest for control (34.8 ± 15.7), followed by Test 1 (29.6 ± 18.1) and Test 2 implants (23.3 ± 22.7), but this difference was not statistically significant (χ(2)  = 0.3).

DISCUSSION AND CONCLUSIONS

Early integration of RBM implants placed into thin maxillary sinus walls was not enhanced by hydrothermal anodization of implant surfaces. This may be related to the initial low stability of the implants and the relatively short healing period. However, non-anodized RBM surfaces showed promising results, with % BIC values comparable to the best estimates of other studies using sinus grafting. Whether the modification of the implant surfaces through anodization with simultaneous sinus grafting would promote enhanced early osseointegration, is a subject of future research.

Complications when augmenting the posterior maxilla

The maxillary posterior edentulous region presents a challenge when planning for restoring missing teeth with a dental implant. The available bone in such cases is often not dense and not adequate for the placement of a properly sized implant because of maxillary sinus pneumatization and alveolar bone loss. Maxillary sinus lift is a predictable procedure to provide adequate bone height for the purpose of implant placement. However, complications are encountered during or after the execution of the sinus lift procedure. In this article, the prevention and management of maxillary sinus complications are discussed.

Use of a palatal pedicle flap for closure of an oroantral fistula

Sinus lifting has become a routine procedure in modern implant dentistry. Despite its predictability, this type of surgery may eventually lead to serious complications and sequelae. Most of the time, such complications are due to technical failures, such as perforation of the sinus membrane during surgery, which may eventually lead to graft loss due to infection within the sinus, which finds its drainage path into the mouth and leads to an oroantral communication (OAC). Epithelization of such a draining duct characterizes an oroantral fistula (OAF). This report presents the use of a palatal pedicle flap to successfully close an OAF in a patient who had previously undergone a sinus lifting procedure. Several surgical techniques may be used in the closure of an OAF, and the choice of a particular technique is subject to the characteristics and location of the communication as well as to the preference of the surgeon. The palatal pedicle flap was successfully chosen in the present case report. The palatal pedicle flap was considered an adequate option for closure of an OAF in a single-stage surgical procedure, with no loss of either keratinized mucosa or buccal sulcus depth in the area of the fistula.

Sinus Floor Augmentation Using Straumann® BoneCeramic™ and Bio-Oss® in a Split Mouth Design and Later Placement of Implants: A 5-Year Report from a Longitudinal Study

BACKGROUND

Straumann® BoneCeramic™ is a synthetic biphasic calcium phosphate (BCP) aimed for sinus floor augmentation. Long-term follow-up of implants placed in BCP after sinus augmentation is still missing.

PURPOSE

The primary aim of the study was to compare survival rates and marginal bone loss of Straumann SLActive implants placed in either BCP (test) or Bio-Oss® (DBB) (control) after sinus floor augmentation. The secondary aim was to calculate graft sinus height at different time points.

MATERIALS AND METHODS

Bilateral sinus floor augmentation was performed in a split mouth model. Eleven patients (mean age 67 years) received 100% BCP on one side and 100% DBB on the contralateral side. After 8 months of graft healing, 62 Straumann SLActive implants were placed. After 5 years of functional loading (6 years after augmentation) of implants, marginal bone levels and grafted sinus height were measured, and implant survival and success rates were calculated.

RESULTS

After 5 years of loading, all prosthetic constructions were in function although two implants were lost in each grafting material. The overall implant survival rate was 93.5% (91.7% for BCP, 91.3% for DBB, and 100% for residual bone). The success rates were 83.3% and 91.3% for BCP and DBB, respectively. There was no statistically significant difference in mean marginal bone level after 5 years between BCP (1.4 ± 1.2 mm) and DBB (1.0 ± 0.7 mm). Graft height reduction (GHR) after 6 years was limited to 6.6% for BCP and 5.8% for DBB.

CONCLUSION

In this limited RCT study, the choice of biomaterial used for sinus floor augmentation did not seem to have any impact on survival rates and marginal bone level of the placed implants after 5 years of functional loading and GHR was minimal.

A 1-Year Clinical and Radiographic Study on Hydrophilic Dental Implants Placed with and without Bone Augmentation Procedures

PURPOSE

The aim of the present 1-year clinical and radiographic study was to evaluate a hydrophilic dental implant when used in everyday cases in one clinic. The purpose was also to compare augmented with nonaugmented sites.

MATERIALS AND METHODS

The study group consisted of 50 consecutive patients treated with 159 dental implants (Proactive, Neoss Ltd, Harrogate, UK) in both mandibles and maxillae. Ninety-two implants were placed with adjunct bone augmentation procedures, whereas 40 implants were placed in augmented maxillary sinus sites. A two-stage procedure was used for 84 implants and a one-stage procedure for 47 implants. Twenty-eight implants were immediately loaded. Implant stability was measured with resonance frequency analysis (RFA) at placement and at prosthesis delivery. The patients were scheduled for checkups after 6 and 12 months in function with clinical and radiographic examinations. Marginal bone level measurements were performed in baseline and follow-up intraoral radiographs.

RESULTS

Two implant failures in two patients were experienced after 1 year of loading, giving a survival rate of 98.7%. One implant in nonaugmented sites and one implant in conjunction with an augmentation procedure (sinus lift), giving a survival rate of 98.5% and 98.9% for healed and augmented sites, respectively (NS). RFA measurements showed 70.2 ± 9.5 ISQ at placement and 76.5 ± 5.9 ISQ (p ≤ 0.001) after a mean healing time of 5.6 ± 1.6 months. The marginal bone loss amounted to 0.7 ± 0.7 mm after 1 year of loading. Frequency distribution showed bone gain or less than 1 mm bone loss for the majority of implants (69.3%), whereas 25.7% showed 1.1 to 2 mm, 5.0% more than 2 mm and no implants more than 3 mm of bone loss.

CONCLUSIONS

The use of Neoss Proactive implants for prosthetic rehabilitation of consecutive patients resulted in predictable clinical and radiographic outcomes after 1 year of loading with no differences between augmented and nonaugmented sites.

A rabbit maxillary sinus model with simultaneous customized-implant placement: Comparative microscopic analysis for the evaluation of surface-treated implants

We describe the use of a rabbit maxillary sinus model, characterized by thin osseous tissue and low bone density, for the evaluation of surface-treated implants by histologically and histomorphometrically comparing the osseointegration patterns depending on the surface treatment methods. Twenty rabbits were randomly assigned to two groups of 10 animals, one receiving 5 × 3 mm customized implants (machined, MA or sandblasted and acid etched, SLA) placed in sinus and the other receiving implants placed in a tibia. Histological observation of the implant placed in sinus shows relatively more active new bone formation, characterized by trabecular bone pattern underneath the cortical bone in sinus as compared with that in tibia. Histomorphometric analysis in the rabbits receiving implants in a tibia, the NBIC (%) associated with the SLA surface implant was greater than that associated with the MA implant at 2 weeks (55.63 ± 8.65% vs. 47.87 ± 10.01%; P > 0.05) and at 4 weeks (61.76 ± 9.49% vs. 42.69 ± 10.97%; P < 0.05). Among rabbits receiving implants in a sinus, the NBIC (%) associated with the SLA surface implant was significantly greater than that associated with the MA surface implant both at 2 weeks (37.25 ± 7.27% vs. 20.98 ± 6.42%; P < 0.05) and at 4 weeks (48.82 ± 6.77% vs. 31.51 ± 9.14%; P < 0.05). As a result, we suggest that the maxillary sinus model is an appropriate animal model for assessing surface-treated implants and may be utilized for the evaluation of surface-treated implants in poor bone quality environment. Microsc. Res. Tech. 78:697-706, 2015.

Biomechanical Stability of Dental Implants in Augmented Maxillary Sites: Results of a Randomized Clinical Study with Four Different Biomaterials and PRF and a Biological View on Guided Bone Regeneration

Introduction. Bone regenerates mainly by periosteal and endosteal humoral and cellular activity, which is given only little concern in surgical techniques and choice of bone grafts for guided bone regeneration. This study investigates on a clinical level the biomechanical stability of augmented sites in maxillary bone when a new class of moldable, self-hardening calcium-phosphate biomaterials (SHB) is used with and without the addition of Platelet Rich Fibrin (aPRF) in the Piezotome-enhanced subperiosteal tunnel-technique (PeSPTT). Material and Methods. 82 patients with horizontal atrophy of anterior maxillary crest were treated with PeSPTT and randomly assigned biphasic (60% HA/40% bTCP) or monophasic (100% bTCP) SHB without or with addition of aPRF. 109 implants were inserted into the augmented sites after 8.3 months and the insertion-torque-value (ITV) measured as clinical expression of the (bio)mechanical stability of the augmented bone and compared to ITVs of a prior study in sinus lifting. Results. Significant better results of (bio)mechanical stability almost by two-fold, expressed by higher ITVs compared to native bone, were achieved with the used biomaterials and more constant results with the addition of aPRF. Conclusion. The use of SHB alone or combined with aPRF seems to be favourable to achieve a superior (bio)mechanical stable restored alveolar bone.

Insufficient evidence for sinus lifts over short implants for dental implant rehabilitation

DATA SOURCES

The Cochrane Oral Health Group's Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL), Medline and Embase databases were searched with no language or date restrictions.

STUDY SELECTION

Two reviewers independently selected studies. Randomised controlled trials (RCTs) of different techniques and materials for augmenting the maxillary sinus for rehabilitation with dental implants that reported the outcome of implant success or failure at least four months after initial loading were considered.

DATA EXTRACTION AND SYNTHESIS

Data were extracted independently by two reviewers and study risk of bias assessed. Results were expressed using fixed-effect models as there were either fewer 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.

RESULTS

Eighteen trials involving 650 patients were included. Five studies were considered to be at low risk of bias, 11 at high risk and two of unclear risk. Four trials (102 patients) 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).Fourteen trials (548 patients) compared different sinus lift techniques. Only three comparisons included more than one trial. 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.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.

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.

TRAP-Positive Multinucleated Giant Cells Are Foreign Body Giant Cells Rather Than Osteoclasts: Results From a Split-Mouth Study in Humans

This study compared the material-specific tissue response to the synthetic, hydroxyapatite-based bone substitute material NanoBone (NB) with that of the xenogeneic, bovine-based bone substitute material Bio-Oss (BO). The sinus cavities of 14 human patients were augmented with NB and BO in a split-mouth design. Six months after augmentation, bone biopsies were extracted for histological and histomorphometric investigation prior to dental implant insertion. The following were evaluated: the cellular inflammatory pattern, the induction of multinucleated giant cells, vascularization, the relative amounts of newly formed bone, connective tissue, and the remaining bone substitute material. NB granules were well integrated in the peri-implant tissue and were surrounded by newly formed bone tissue. Multinucleated giant cells were visible on the surfaces of the remaining granules. BO granules were integrated into the newly formed bone tissue, which originated from active osteoblasts on their surface. Histomorphometric analysis showed a significantly higher number of multinucleated giant cells and blood vessels in the NB group compared to the BO group. No statistical differences were observed in regard to connective tissue, remaining bone substitute, and newly formed bone. The results of this study highlight the different cellular reactions to synthetic and xenogeneic bone substitute materials. The significantly higher number of multinucleated giant cells within the NB implantation bed seems to have no effect on its biodegradation. Accordingly, the multinucleated giant cells observed within the NB implantation bed have characteristics more similar to those of foreign body giant cells than to those of osteoclasts.

Coalescence of inter: Osteotomy bone graft material inserted via separate transcrestal sinus osteotomies: A case report and concise review of the literature

When multiple implants are to be placed, and a pneumatized sinus exists, the published reports suggest that the lateral window approach (LWA) is favored for sinus floor augmentation. Simultaneously, if a transcrestal sinus floor augmentation has been carried out (bone-added osteotome sinus floor elevation), the reports are restricted to single implant placement at any site. The aim of this study was to evaluate the clinical and radiographic outcomes at adjacent transcrestal sinus augmentation grafts using deproteinized bovine bone material, with the immediate placement of submerged adjacent implants, and so determining the fate of the graft material. The progressive loss of the inter-implant graft is reported for the LWA Technique. However, this novel coalescence method has shown a progressive increase in the inter-implant graft region, thus inferring a positive bony regeneration and remodelling at the region. These results indicate that the carrying out of a large scale study is warranted to confirm the efficacy of this technique.

Preoperative implant planning considering alveolar bone grafting needs and complication prediction using panoramic versus CBCT images

Purpose

This study was performed to determine the efficacy of observers' prediction for the need of bone grafting and presence of perioperative complications on the basis of cone-beam computed tomography (CBCT) and panoramic radiographic (PAN) planning as compared to the surgical outcome.

Materials and Methods

One hundred and eight partially edentulous patients with a need for implant rehabilitation were referred for preoperative imaging. Imaging consisted of PAN and CBCT images. Four observers carried out implant planning using PAN image datasets, and at least one month later, using CBCT image datasets. Based on their own planning, the observers assessed the need for bone graft augmentation as well as complication prediction. The implant length and diameter, the need for bone graft augmentation, and the occurrence of anatomical complications during planning and implant placement were statistically compared.

Results

In the 108 patients, 365 implants were installed. Receiver operating characteristic analyses of both PAN and CBCT preoperative planning showed that CBCT performed better than PAN-based planning with respect to the need for bone graft augmentation and perioperative complications. The sensitivity and the specificity of CBCT for implant complications were 96.5% and 90.5%, respectively, and for bone graft augmentation, they were 95.2% and 96.3%, respectively. Significant differences were found between PAN-based planning and the surgery of posterior implant lengths.

Conclusion

Our findings indicated that CBCT-based preoperative implant planning enabled treatment planning with a higher degree of prediction and agreement as compared to the surgical standard. In PAN-based surgery, the prediction of implant length was poor.

Long-term survival rate of implants placed in conjunction with 246 sinus floor elevation procedures: results of a 15-year retrospective study

OBJECTIVES

The aim of the present long-term study was to retrospectively evaluate the survival rate of implants placed in regenerated maxillary sinuses and to assess the influence of hypothetical predictors of implant failure.

METHODS

A database including 218 patients who received dental implants after sinus lift procedures was analyzed. The following variables were systematically included and evaluated: type of graft material used, number of surgeries performed, and use of membranes to cover the lateral antrostomy and/or to repair accidental Schneiderian membrane perforations. The Kaplan-Meier estimator was used for comparisons among the groups.

RESULTS

A total of 589 dental implants were positioned in 246 grafted sinuses and were in function for 3-186 months. The Kaplan-Meier cumulative survival rate was 98.3% after 15.5 years of follow-up. All implant losses occurred within 52 months (4.3 years) after augmentation. According to the log-rank test, no statistically significant difference was shown between each patient/implant variable (p>0.05).

CONCLUSIONS

Despite the limitations inherent in this type of study, no statistically significant differences between the groups could be found. Intraoperative Schneiderian membrane perforations did not affect the outcome of the implants positioned.

CLINICAL SIGNIFICANCE

The present long-term study is intended as a reference for clinicians approaching sinus floor elevation surgery in order to provide them with relevant operative findings. Since all the drawbacks occurred within the first 5 years, medium-term follow-up studies could be suitable for further retrospective evaluations.

Maxillary Sinus Augmentation without Grafting Material with Simultaneous Implant Installation: A Three-Dimensional Finite Element Analysis

PURPOSE

The study aims to provide a theoretical guidance of postmaxillary implant in the augmented sinus without grafting materials by establishing a three-dimensional model of this new implant restorative technique, evaluating failure risk of sinus augmentation without grafting materials of different alveolar ridge heights, and analyzing stress distribution of different healing stage.

MATERIALS AND METHODS

Seventeen three-dimensional finite element models of a posterior maxillary region with sinus mucosa and different elevation heights were constructed according to anatomical data of sinus area, and the standard implant model based on Nobel Biocare implant system were created via computer-aided design software. All materials were assumed to be isotropic and linearly elastic. Axial force of 150 N was applied. The von Mises stress, stress distribution, and implant displacement were calculated with software.

RESULTS

With the height of the alveolar ridge reducing, the maximum von Mises stress of tissues and the displacement of the implant are on the rise, especially when the height of the bone is less than 7 mm. When the height decreased to 4 mm, the data may be doubled. After the stiff callus stage, the stress and displacement were close to the control model.

CONCLUSION

For maxillary sinus augmentation without grafting material implant technique, the stress of different tissues and the displacement of the implant were not increased much when the height of alveolar ridge is more than 7 mm. But if the alveolar bone height is less than 4 mm, this implant technique is not suggested. Immediately loading is not suggested and the loading opportunity should be after the stiff callus stage at least to improve the success rate.

Anorganic bovine bone (ABB) vs. autologous bone (AB) plus ABB in maxillary sinus grafting. A prospective non-randomized clinical and histomorphometrical trial

OBJECTIVES

This investigation focused on histological characteristics and 5-year implant survival after sinus floor augmentation with anorganic bovine bone (ABB, Bio-Oss) and ABB plus autologous bone (AB) with a ratio of 1/1.

MATERIAL AND METHODS

Nineteen consecutive patients with bony atrophy of the posterior edentulous maxilla and a vertical bone height ≤4 mm were prospectively included in this study. In the first surgical stage, the maxillary sinus was non-randomized either augmented with ABB alone (n = 12) or a 1/1 mixture of ABB and AB (n = 7). After a mean healing period of 167 days, biopsies were harvested in the region of the grafted sinus with a trephine burr and implants were placed simultaneously, ABB n = 18 and ABB + AB n = 12. The samples were microradiographically and histomorphometrically analyzed judging the newly formed bone (bone volume, BV), residual bone substitute material volume (BSMV), and intertrabecular volume (soft tissue volume, ITV) in the region of the augmented maxillary sinus. Implant survival was retrospectively evaluated from patient's records.

RESULTS

No significant difference in residual bone substitute material (BSMV) in the ABB group (31.21 ± 7.74%) and the group with the mixture of ABB and AB (28.41 ± 8.43%) was histomorphologically determined. Concerning the de novo bone formation, also both groups showed statistically insignificant outcomes; ABB 26.02 ± 5.23% and ABB + AB 27.50 ± 6.31%. In all cases, implants were installed in the augmented sites with sufficient primary stability. After a mean time in function of 5 years and 2 months, implant survival was 93.75% in the ABB and 92.86% in the ABB + AB group with no statistically significant differences.

CONCLUSION

The usage of ABB plus AB to a 1/1 ratio leads to an amount of newly formed bone comparable with the solitary use of ABB after grafting of the maxillary sinus. Considering that ABB is a non-resorbable bone substitute, it can be hypothesized that this leads to stable bone over time and long-term implant success. Importantly, in the sole use of ABB, bone grafting and therefore donor site morbidities can be avoided.

Nanocrystalline Hydroxyapatite-Based Material Already Contributes to Implant Stability After 3 Months: A Clinical and Radiologic 3-Year Follow-up Investigation

The present study reports on a 3-year clinical and radiologic follow-up investigation of dental implants placed 3 and 6 months after sinus augmentation in 14 patients. Augmentation was performed with a synthetic bone substitute material composed of nanocrystalline hydroxyapatite. The aim of the study was to determine how the integration period of the bone substitute material, that is, 3 months or 6 months, influences implant integration within the patient's upper jaw. Therefore, the following clinical and radiologic parameters were investigated: implant being in situ; Periotest value; and presence of peri-implant osteolysis, bleeding on probing, plaque, and soft tissue recession around the implants. At the follow-up investigation 3 years after placement, 23 of 24 implants were in situ and suitable for prosthetic rehabilitation. No implants in either study group were mobile or showed peri-implant osteolysis. Only a few implants showed plaque or soft tissue variations. Within its limits, the present study showed comparable clinical performance of dental implants placed 3 months after sinus floor augmentation to implants placed 6 months after augmentation. The results of all investigated parameters were in accordance with results found in the literature. It can be concluded that augmentation with the applied synthetic bone substitute material already forms a sufficient implantation bed 3 months after augmentation, which enables long-term, stable, implant-retained restoration. These findings might contribute to a reduced healing time after augmentation, which would be favorable for patients and clinicians.

Injectable bone tissue engineering using expanded mesenchymal stem cells

Patients suffering from bone defects are often treated with autologous bone transplants, but this therapy can cause many complications. New approaches are therefore needed to improve treatment for bone defects, and stem cell therapy presents an exciting alternative approach. Although extensive evidence from basic studies using stem cells has been reported, few clinical applications using stem cells for bone tissue engineering have been developed. We investigated whether injectable tissue-engineered bone (TEB) composed of mesenchymal stem cells (MSCs) and platelet-rich plasma was able to regenerate functional bone in alveolar deficiencies. We performed these studies in animals and subsequently carried out large-scale clinical studies in patients with long-term follow-up; these showed good bone formation using minimally invasive MSC transplantation. All patients exhibited significantly improved bone volume with no side effects. Newly formed bone areas at 3 months were significantly increased over the preoperation baseline (p < .001) and reached levels equivalent to that of native bone. No significant bone resorption occurred during long-term follow-up. Injectable TEB restored masticatory function in patients. This novel clinical approach represents an effective therapeutic utilization of bone tissue engineering.

A Retrospective Study on Immediate Placement of Neoss Implants with Early Loading of Full-Arch Bridges

BACKGROUND

Full-arch clearances of compromised teeth and placement of implant-supported prostheses is one solution for the prosthetic rehabilitation of partially dentate patients.

PURPOSE

To retrospectively evaluate treatment outcomes after full clearance, immediate placement, and early loading of full-arch fixed bridges.

MATERIALS AND METHODS

Fifty-five patients subjected to full clearance and placement of 284 Neoss implants (Bimodal™ and Proactive™, Neoss Ltd, Harrogate, UK) in 29 edentulous maxillae and 26 mandibles for early loading (1 to 3 days) of a provisional full-arch bridge were retrospectively evaluated after 1 to 6 years of loading. Osstell™ measurements (Osstell AB, Göteborg, Sweden) were taken at placement and after 3 to 9 months when the provisional bridge was replaced with a permanent one. Marginal bone levels were measured in intraoral radiographs.

RESULTS

All patients (100%) wore a fixed bridge at the time of finalizing the study. A total of 18 failures (6.3%) were encountered during the follow-up, giving an overall cumulative survival rate of 93.7%. All failures occurred in the maxilla (10.6%), and no implants were lost in the mandible. More Bimodal™ (9.0%) than Proactive™ (4.1%) implants failed. Failing implants showed a significantly lower mean primary stability than successful ones (p = .015). Failed cases showed a significantly lower average ISQ for all implants (p = .015) and a marked decrease to the second registration, while successful cases showed and maintained high ISQs. The average bone loss after 1 year was 0.8 ± 0.5 mm.

CONCLUSIONS

Full-arch clearance of severely diseased teeth followed by immediate placement of Neoss implants, early loading with provisional full-arch bridges, and subsequent permanent bridges is a possible treatment modality for partially dentate patients. Caution with this approach is recommended for the maxilla, as opposed to the mandible.

Evaluation of the posterior superior alveolar artery and the maxillary sinus with CBCT

Assessment of the maxillary sinus anatomy before sinus augmentation is important for avoiding surgical complications, because of the close anatomical relationship between the posterior maxillary teeth and the maxillary sinus. The posterior superior alveolar artery (PSAA) is the branch of the maxillary artery that supplies the lateral sinus wall and overlying membrane. We evaluated the location of the PSAA and its relationship to the alveolar ridge and maxillary sinus using cone beam computed tomography (CBCT). The study group consisted of 135 CBCT scans (270 sinuses) obtained from the archive of the dentomaxillofacial radiology department at Yeditepe University Faculty of Dentistry, Istanbul, Turkey. The distance between the lower border of the artery and the alveolar crest, bone height from the sinus floor to the ridge crest, distance from the artery to the medial sinus wall, and the diameter and location of the artery were determined. The occurrence of septa and pathology were recorded from CBCT scans. The PSAA was observed in 89.3% of sinuses, and 71.1% of arteries were intraosseous with diameters mostly < 1 mm (68.9%). The prevalence of sinus septa was 55.2%, and that of sinus pathology was 57.4%. The mean age was 43.07 ± 17.55 years. There was a statistically significant difference between the location of the artery and gender (p < 0.05). The prevalence of sinus membrane thickening was 57.4%. Detailed knowledge about the location of the PSAA and sinus morphology may be obtained with CBCT before maxillary sinus surgery.

Recombinant human bone morphogenetic protein-2 stimulates the osteogenic potential of the Schneiderian membrane: a histometric analysis in rabbits

This study evaluated the osteoinductive effect of the recombinant human bone morphogenetic protein-2 (rhBMP-2)-coated biphasic calcium phosphate (BCP) carrier system on the grafted sinus area, including surrounding tissues and the Schneiderian membrane. A total of 18 male rabbits were used in this study; two for in vitro and 16 for in vivo experiments. Schneiderian membranes taken from two animals were cultured with or without rhBMP-2, and quantitative reverse transcriptase-polymerase chain reaction analysis was performed. Both maxillary sinuses in each of the 16 animals were used to compare the in vivo effects of rhBMP-2-coated BCP (experimental group) and BCP alone (control group). In each animal, rhBMP-2-coated BCP was grafted into one of the maxillary sinuses, and the same amount of BCP alone was grafted into the contralateral site in random order. Radiologic and histometric analyses were performed at 2 and 8 weeks after surgery. After 2 days of culturing with or without rhBMP-2, a significant increase in the expression of early osteoblasts (RUNX2, type I collagen, alkaline phosphatase, and osteopontin) could be observed. Different histologic healing patterns were observed in experimental and control sites: newly formed bone lining the reflected sinus membrane without bone formation was observed at the central areas of experimental sites (window=0.06%; center=0%; membrane=20.86% of new bone), whereas evenly distributed new bone formation was observed at the control sites (window=7.27%; center=7.41%; membrane=15.58% of new bone).The augmented volume was well maintained at both the experimental and control sites during the experimental period, but at 2 weeks, the augmented volume was greater at the experimental sites than at the control sites (232.62 and 195.29 mm(3), respectively; p<0.001). These results suggest that good space maintenance in sinus augmentation is achieved with BCP, while the osteoinductive potential of the sinus membrane is activated at the early stage of healing with rhBMP-2.

Healing properties of implants inserted concomitantly with anorganic bovine bone. A histomorphometric human study

BACKGROUND

The present prospective, randomized, double-blind study evaluated the bone-forming process around implants inserted simultaneously with anorganic bovine bone (ABB) in sinus grafting.

METHODS

A total of 18 threaded mini-implants with Osseotite (O) and Nanotite (N) surfaces were placed in seven patients (nine sites). After 12 months, the implants were retrieved and processed for histological analysis. A total of 18 cutting and grinding sections were investigated with bright-field light microscopy, circularly polarized light microscopy (CPLM), confocal scanning laser microscope (CSLM), and scanning electron microscope (SEM) with energy dispersive spectrometer (EDS).

RESULTS

The bone-to-implant contact rate in native crestal bone was 62.6 ± 0.4% for N implants and 54.3 ± 0.5% for the O implants (p = 0.001). The collagen fibre density, as assessed by CPLM, was 79.8 ± 6.0 nm for the N group and 74.6 ± 4.6 nm for the O group (p < 0.05). Line scan EDS starting from ABB to newly formed bone showed a decrease in calcium content and an increase of carbon while phosphorus content was constant.

CONCLUSIONS

While the N surface improved the peri-implant endosseous healing properties in the native bone, when compared to the O surface, it did not improve the healing properties in the bone-graft area.

Short implants in maxillary and mandibular rehabilitations: interim results (6 to 42 months) of a prospective study

The aim of this single-cohort study was to evaluate clinical survival and success of partial rehabilitation supported by reduced-length implants in maxilla and mandible. Data from 53 short implants placed in 41 patients are presented. Before surgery mean residual bone height was 6.21 ± 1.05 mm in the upper jaw and 10.73 ± 1.63 mm in the mandible. None of the implants failed, and the cumulative survival rate was 100% at 1 year after prosthetic loading. Mean peri-implant bone loss was 0.69 ± 0.24 mm for maxillary implants and 0.73 ± 0.23 mm for mandibular implants, and there was no significant difference between the 2 jaws. No complications were recorded. Despite the limitations of this study concerning study design and sample size, short implants may be considered effective in supporting partial rehabilitation in both maxilla and mandible. More well-designed studies with a larger sample size and longer follow-up are needed to validate the use of short implants.

Use of plasma rich in growth factor for schneiderian membrane management during maxillary sinus augmentation procedure

The aim of this pilot study was to present a novel technique for the management of the Schneiderian membrane during maxillary sinus lift surgery using plasma rich in growth factors (PRGF). Eight maxillary sinuses were augmented in 8 patients. Two small perforations of the Schneiderian membrane occurred during the lifting procedure, which were solved using the PRGF clot before grafting the site with PRGF and anorganic bovine bone. With the exception of 1 patient who experienced pain following an acute sinus infection after 3 days of uneventful healing, the patients' postoperative quality of life was generally good. The most common complication (50% of cases) was hematoma, which disappeared after 1 week. Despite the limitations of this study concerning the sample size and the study design, the use of PRGF may be helpful in reducing complications following sinus lift surgery. More well-designed studies, with larger sample size, are needed to validate this protocol.

One-year clinical and radiographic results with a novel hydrophilic titanium dental implant

BACKGROUND

New implant designs are continuously introduced to the market. It is important to evaluate and report on their clinical performance when used in everyday practice.

PURPOSE

The aim of the present study was to evaluate the clinical performance of a novel hydrophilic dental implant for 1 year.

MATERIALS AND METHODS

A total of 49 patients previously treated with 102 hydrophilic dental implants (Neoss Proactive, Neoss Ltd, Harrogate, UK) were retrospectively evaluated with regard to survival rate and marginal bone loss. Fifty-four implants were installed in maxillae and 48 in mandibles to replace single teeth (n = 21), to support partial bridges (n = 26), total maxillary bridges (n = 2), or mandibular overdentures (n = 2). The majority of patients (n = 37) had implants placed in healed sites without any adjunctive procedures. In 12 patients, implants were immediately placed in extraction sockets or in conjunction with maxillary sinus floor augmentation. All implant sites had been classified according to the Lekholm and Zarb index. Baseline and 1-year intraoral radiographs were used to calculate marginal bone levels and bone loss. Implant stability quotient (ISQ) measurements had been taken at placement and after 3 to 4 months of healing

RESULTS

The implants became rapidly covered with blood at the first contact. One implant was lost, giving a cumulative survival rate (CSR) of 99.0% after 1 year. The marginal bone loss amounted to 0.7 ± 0.6 mm with 3.5% of the implants showing more than 2 mm of bone loss and no implant more than 3 mm bone loss after 1 year. The primary stability was found to be 72.7 ± 7.5 ISQ, which slightly increased to 73.6 ± 7.2 ISQ (NS) after 3 to 4 months of healing. The stability was significantly higher in the mandible than in the maxilla at placement and after healing.

CONCLUSION

In this limited clinical study, the use of a novel hydrophilic dental implant results in favorable short-term outcomes.

Tilted implants for full-arch rehabilitations in completely edentulous maxilla: a retrospective study

Purpose. The aims of this study were to assess the treatment outcome of immediately loaded full-arch fixed bridges anchored to both tilted and axially placed implants in the edentulous maxilla and to evaluate the incidence of biological and prosthetic complications. Materials and Methods. Thirty-four patients (18 women and 16 men) were included in the study. Each patient received a maxillary full-arch fixed bridge supported by two axial implants and two distal tilted implants. A total of 136 implants were inserted. Loading was applied within 48 hours of surgery and definitive restorations were placed 4 to 6 months later. Patients were scheduled for followup at 6, 12, 18, and 24 months and annually up to 5 years. At each followup plaque level and bleeding scores were assessed and every complication was recorded. Results. The overall follow-up range was 12 to 73 months (mean 38.8 months). No implant failures were recorded to date, leading to a cumulative implant survival rate of 100%. Biological complications were recorded such as alveolar mucositis (11.8% patients), peri-implantitis (5.9% patients), and temporomandibular joint pain (5.9% patients). The most common prosthetic complications were the fracture or detachment of one or multiple acrylic teeth in both the temporary (20.6% patients) and definitive (17.7% patients) prosthesis and the minor acrylic fractures in the temporary (14.7% patients) and definitive (2.9% patients) prosthesis. Hygienic complications occurred in 38.2% patients. No patients' dissatisfactions were recorded. Conclusions. The high cumulative implant survival rate indicates that this technique could be considered a viable treatment option. An effective recall program is important to early intercept and correct prosthetic and biologic complications in order to avoid implant and prosthetic failures.