Short Implants Placed One-Stage in Maxillae and Mandibles: A Retrospective Clinical Study with 1 to 9 Years of Follow-Up

Comparative biomechanics of all-on-4 and vertical implant placement in asymmetrical mandibular: a finite element study

BACKGROUND

Clinical scenarios frequently present challenges when patients exhibit asymmetrical mandibular atrophy. The dilemma arises: should we adhere to the conventional All-on-4 technique, or should we contemplate placing vertically oriented implants on the side with sufficient bone mass? This study aims to employ three-dimensional finite element analysis to simulate and explore the biomechanical advantages of each approach.

METHODS

A finite element model, derived from computed tomography (CT) data, was utilized to simulate the nonhomogeneous features of the mandible. Three configurations-All-on-4, All-on-5-v and All-on-5-o were studied. Vertical and oblique forces of 200 N were applied unilaterally, and vertical force of 100 N was applied anteriorly to simulate different masticatory mechanisms. The maximum von Mises stresses on the implant and framework were recorded, as well as the maximum equivalent strain in the peri-implant bone.

RESULTS

The maximum stress values for all designs were located at the neck of the distal implant, and the maximum strains in the bone tissue were located around the distal implant. The All-on-5-o and All-on-5-v models exhibited reduced stresses and strains compared to All-on-4, highlighting the potential benefits of the additional implant. There were no considerable differences in stresses and strains between the All-on-5-o and All-on-5-v groups.

CONCLUSIONS

With the presence of adequate bone volume on one side and severe atrophy of the contralateral bone, while the "All-on-4 concept" is a viable approach, vertical implant placement optimizes the transfer of forces between components and tissues.

Evaluation of Quality of Life and Satisfaction with Fixed Prostheses on Zygomatic Implants vs All-on-Four Concept: A Randomized Clinical Study

AIM

To compare between the rehabilitation of atrophied maxilla with fixed prosthesis using two posterior zygomatic implants and two conventional anterior implants or four implants inserted according to the all-on-four concept regarding the patient quality of life and satisfaction after one year of prosthesis insertion.

MATERIALS AND METHODS

Thirty-six patients with atrophic edentulous maxillae were randomized into two groups: Group I (rehabilitated with fixed prostheses supported by two zygomatic and two conventional implants in the anterior region) and group II (fixed prostheses on four implants in the anterior region following an all-on-four concept). One year after the placement of the definitive prostheses, patients completed oral health impact profile-14 and satisfaction questionnaires.

RESULTS

All patients were satisfied regarding retention, stability, occlusion, comfort, cleaning, speaking, chewing, bolus quality, appearance, handling, prosthesis apart, and embarrassing, with no significant significance between two groups except satisfaction with surgical procedures and healing period.

CONCLUSIONS

Using two distally tilted zygomatic implants or all-on-four concept to rehabilitate atrophied maxilla by fixed detachable prosthesis could be considered a promising functional and esthetic treatment option regarding the patient satisfaction.

CLINICAL SIGNIFICANCE

Traditionally, treatment of maxillary atrophied ridges was done by bone grafting or sinus-lifting techniques; however, using all-on-four concept or zygomatic implants was a successful treatment as it has high success rates and highly satisfied by the patients. How to cite this article: Nagib MA, Ibrahim AM, Abdel-Rahman FH, et al. Evaluation of Quality of Life and Satisfaction with Fixed Prostheses on Zygomatic Implants vs All-on-Four Concept: A Randomized Clinical Study. J Contemp Dent Pract 2024;25(2):141-147.

Peri-implant tissue health and patient satisfaction of vertical versus inclined posterior implants used to support overdentures with bar attachments. A one-year randomized trial

INTRODUCTION

This study aimed to evaluate peri-implant tissue health and patient satisfaction of vertical and inclined posterior implants for mandibular bar overdentures.

MATERIALS AND METHODS

Thirty edentulous participants received four implants in the interforaminal area of the mandible. The patients were randomly assigned into two equal groups; (1) vertical group (control): all implants were inserted vertically parallel to each other. Inclined group (study): the anterior implants were placed vertically, and the posterior implants were tilted 30° distally. Hader bar attachment with two 7 mm-distal cantilevers (vertical group) and without cantilevers (inclined group) was used to connect the implants to mandibular overdentures. Peri-implant tissue health (Plaque [PL] and gingival [GI] indices, pocket depth [PD], and crestal bone loss [CBL]) were evaluated after denture insertion (T0), 6 (T6), and 12 (T12) months after insertion. Patient satisfaction was evaluated using a visual analog scale after 12 months.

RESULTS

At T12, the vertical group showed significantly higher PL, PD, and CBL than the inclined group for anterior (p < 0.037) and posterior (p < 0.017) implants. The vertical group showed significantly higher GI than the inclined group for anterior implants (p = 0.003), and the inclined group showed significantly higher GI than the vertical group for posterior implants (p = 0.016). The inclined group showed significantly higher scores for general satisfaction (p = 0.049), prosthesis as a part of you (p = 0.013), appearance (p < 0.001), stability (p = 0.002), ease of cleaning (p < 0.001), and comfort (p = 0.001) than the vertical group.

CONCLUSION

Inclined posterior implants used to support mandibular bar overdentures are recommended than vertical implants, as it was associated with improved patient satisfaction and peri-implant tissue health.

Ten-year follow-up of full-arch rehabilitations supported by implants in immediate function with nasal and full-length palatine bicortical anchorage on the anterior maxilla

PURPOSE

To evaluate the immediate function of anterior maxillary implants.

METHODS

One hundred nine patients (42 males and 67 females; average age 55.2 years; range 38-81 years) were followed for 10 years. One hundred eighty-eight implants using nasal and full-length palatine cortical anchorage were inserted in the anterior section of the maxilla together with 188 tilted implants placed posteriorly. Outcome measures were implant success and survival, prosthesis survival, bone loss, and the incidence of biological and mechanical complications. Cumulative success and survival were computed through Kaplan-Meyer product limit estimator (at patient level) and life tables (implant level).

RESULTS

Four patients lost one implant each, giving a 10-year cumulative survival rate of 95.8% and 97.7% using the patient and the implant as the unit of analysis, respectively. The prosthesis survival rate was 98.2%, and the average marginal bone loss was 1.79 mm (1.06 mm). The cumulative success rate was 89.1% and 92.5% using the patient and the implant as the unit of analysis, respectively.

CONCLUSION

Full-arch fixed prosthetic rehabilitations supported by immediately functional implants inserted in the anterior maxilla with bicortical anchorage together with posterior-tilted implants are viable in the long term.

Short strategic implants for mandibular removable partial dentures: One-year results from a pilot randomized crossover abutment type study

Objectives

The present pilot study analyzed two abutment types (a retentive ball and a non‐retentive dome) in implant‐assisted removable partial dentures (IARPDs) on 6 mm short implants with respect to clinical, radiological, and patient‐reported outcomes (PROs), during the first year.

Materials and Methods

Two implants were placed bilaterally in mandibular molar sites, converting existing free‐end removable partial dentures (RPDs) to IARPDs. Twelve subjects were randomized to initially receive either the dome (Group A, n = 6) or the ball abutment (Group B, n = 6). After eight weeks, the abutments were exchanged. After another 8 weeks, the participants were given the choice of one of the abutments. Mean values and standard deviations (SD) were calculated, and random‐effect linear regression analyses were applied to analyze marginal bone level alterations and PROs (α < .05).

Results

Twelve participants were included in the study; however, one dropout occurred. Patient ratings increased significantly in both study groups. The majority of the participants (82%) ultimately chose the ball abutment. The implant survival rate was 100%, and the success rate was 90.9% twelve months after implant placement (mean peri‐implant bone‐loss: −1.2; SD: 0.6 mm) without a statistically significant difference between the study groups, in terms of clinical‐ and radiological outcomes.

Conclusion

Placing 6 mm short implants at mandibular molar sites of RPD wearers seems to be a viable treatment option, based on this investigation with a short‐term follow‐up. Although only minor differences between the two abutments were observed, patients seem to prefer the ball over the dome abutment.

Clinical performance of narrow-diameter titanium-zirconium implants in immediately loaded fixed full-arch prostheses: a 2-year clinical study

Objectives

The aim of this study was to evaluate the outcomes of immediate fixed full-arch prostheses supported by axial or tilted narrow-diameter Ti-Zr implants (3.3 mm) (Roxolid®, Institut Straumann® AG, Basel, Switzerland) (NDIs) in combination with standard-diameter implants up to 2 years’ follow-up.

Materials and methods

The study was conducted at Kocaeli University Faculty of Dentistry from 2016 to 2018. 37 jaws of 28 patients with an average age of 52 years were rehabilitated with fixed full-arch prostheses supported by 179 implants. Cumulative survival rate (CSR), implant success, marginal bone loss (MBL), and prosthetic survival rate as well as complications were analyzed.

Results

Total CSR of 99.4% and 98.5% for all and narrow implants respectively have been observed at 2 years’ follow-up. No prosthesis failures were observed, yielding a cumulative prosthetic survival rate of 100%. The NDIs achieved 0.63 mm MBL at 1 year and 1.02 mm at 2 years. The mean MBL at 1 year was 0.51 mm (mandible 0.63 mm/maxilla 0.41 mm) and 0.73 mm (mandible 0.90 mm/maxilla 0.43 mm) at 2 years. Both implant angulation and loading protocol did not influence the MBL.

Conclusions

The combination of narrow-diameter implants with standard-diameter implants in immediate fixed full-arch rehabilitation has a good prognosis to become a new standard of care for severely atrophic jaws.

Clinical relevance

The use of narrow-diameter implants in fixed full-arch rehabilitations in atrophic ridges would be a successful and predictable treatment approach.

Biomechanical properties of the bone during implant placement

Background

In this research the biomechanical properties of a bone model was examined. Porcine ribs are used as experimental model. The objective of this research was to investigate and compare the biomechanical properties of the bone model before and after implant placement.

Methods

The bone samples were divided in three groups, Group 1 where ALL-ON-FOUR protocol was used during pre-drilling and placing the implants, Group 2 where ALL-ON-FOUR protocol was used during pre-drilling, and implants were not placed, and Group 3 consisting of intact bones served as a control group. Static and dynamic loading was applied for examining the model samples. Kruskal–Wallis statistical test and as a post-hoc test Mann–Whitney U test was performed to analyze experimental results.

Results

According to the results of the static loading, there was no significant difference between the implanted and original ribs, however, the toughness values of the bones decreased largely on account of predrilling the bones. The analysis of dynamic fatigue measurements by Kruskal–Wallis test showed significant differences between the intact and predrilled bones.

Conclusion

The pre-drilled bone was much weaker in both static and dynamic tests than the natural or implanted specimens. According to the results of the dynamic tests and after a certain loading cycle the implanted samples behaved the same way as the control samples, which suggests that implantation have stabilized the skeletal bone structure.

Can ceramic veneer spark erosion and mechanical cycling affect the accuracy of milled complete-arch frameworks supported by 6 implants?

STATEMENT OF PROBLEM

Milling is a well-established method for manufacturing prosthetic frameworks. However, information about the influence of ceramic veneer and spark erosion on the accuracy of the all-on-six complete-arch fixed frameworks manufactured from different materials is lacking.

PURPOSE

The purpose of this in vitro study was to compare the accuracy of milled complete-arch fixed frameworks with zirconia, cobalt-chromium, and titanium at different steps of their manufacturing process and the influence of mechanical cycling.

MATERIAL AND METHODS

Fifteen milled complete-arch fixed frameworks, supported by 6 implants, were made in zirconia, cobalt-chromium, and titanium (n=5). The fit was measured by the single-screw test protocol. Stress was measured by photoelastic analysis. The loosening torque was evaluated by tightening the screws, retightening them after 10 minutes, and then evaluating the loosening torque 24 hours later. Thereafter, all frameworks received ceramic veneer, and the previous tests were repeated. Cobalt-chromium and titanium frameworks received spark erosion after ceramic veneer, and all analyses were repeated. Before and after mechanical cycling, loosening torque was evaluated. The results were subjected to 2-way repeated-measures ANOVA and the Bonferroni test (α=.05).

RESULTS

Titanium presented higher fit values than zirconia (P=.037) and similar to cobalt-chromium frameworks (P>.05) at baseline. After ceramic veneer, higher fit levels were observed for zirconia (P=.001) and cobalt-chromium (P=.008). Titanium showed higher stress values (P<.05) regardless of time. Baseline for all materials presented lower stress values (P<.05). Higher loosening torque values were found for the titanium group at baseline (P<.001) and after ceramic veneer (P<.001). Spark erosion improved fit and loosening torque values only for cobalt-chromium (P<.05). Mechanical cycling did not influence the loosening torque (P>.05).

CONCLUSIONS

Titanium milled complete-arch fixed frameworks presented poorer fit values than zirconia, although the loosening torque at baseline was higher. Ceramic veneer increased the fit levels for zirconia and cobalt-chromium, decreased the loosening torque values for cobalt-chromium, and enhanced stress levels. Spark erosion can be a reliable technique to improve fit and loosening torque for cobalt-chromium frameworks. Mechanical cycling did not decrease loosening torque.

All-On-Four Protocol With Immediate Load on Short Implants in an Atrophic Mandible: A Case Report with a 4-Year Follow-Up

Purpose:

Edentulism has been demonstrated to have negative social and psychological effects on individuals that include adverse impacts on facial and oral esthetics, masticatory function and speech abilities, that when combined, are translated into significant reductions in patients’ quality of lives. It is well-known that immediate placement of implants is a challenging surgical procedure that requires proper treatment planning and surgical techniques. Therefore, the present study describes a 4-year follow-up case report where short implants were placed in an atrophic mandibule and were loaded with the utilization of an all-on-four prosthetic protocol.

Case report:

A 54 year-old woman dissatisfied with her oral and facial esthetics, masticatory function and speech ability came to the implantology clinic of the Positivo University seeking for oral rehabilitation treatment. After detailed physical and clinical examination, a Computer Tomography scan (CT-scan) was performed to determine the patient’s bone ridge density, dimensions and eligibility for the placement of dental implants. The CT-scan results have indicated the presence of an extremely atrophic mandibular bone ridge. The CT-scan was also used as an aid during the final restoration treatment planning in terms of vertical dimension of occlusion, masticatory function, and stabilization of the lower denture. An all-on-four protocol supported by short implants was then treatment-planned to reduce time, costs and morbidity, and also to achieve superior immediate esthetic results and masticatory function. To reconstruct the patient’s atrophic edentulous mandibule, 4 short implants, including 2 distally tilted, were placed with a final torque of 45 Ncm.

Results:

Following the development and implementation of a complex treatment plan, the patient displayed stable soft and hard tissues at 4-year postoperative follow-up assessment, demonstrating the effectiveness of the all-on-four technique supported by short implants.

Conclusion:

Within the limits of this study, the present case report demonstrated that the all-on-four prosthetic protocol with immediate loading on short implant was effective in an atrophic mandible over a 4-year follow-up.

Relationship Between Crestal Bone Levels and Crown-to-Implant Ratio of Ultra-Short Implants With a Microrough Surface: A Prospective Study With 48 Months of Follow-Up

The aim of this cohort study was to investigate the relationship between crestal bone levels and crown-to-implant ratio of ultra-short implants, after functional loading. Sixty patients with single or partial edentulism and alveolar bone atrophy were enrolled and treated between December 2009 and January 2016. Without using bone-grafting procedures, patients were rehabilitated with ultra-short implants characterized by a microrough surface and a 6-mm length. Clinical and anatomical crown-to-implant (C/I) ratios and crestal bone levels (CBL) were measured after a follow-up period ranging from 12 to 72 months; all peri-implant and prosthetic parameters were recorded. The data collected were statistically analyzed ( P = .05). A total of 47 patients with 66 ultra-short implants were completely followed up according to described protocol. The mean follow-up was 48.5 ± 19.1 months. The mean anatomical C/I ratio was 2.2, while the mean clinical C/I ratio was 2.6 ± 0.6 at baseline and 2.8 ± 0.6 at the last follow-up appointment. Mean CBL as calculated at the baseline was 0.7 ± 0.5 mm, while at the last appointment it measured 1.0 ± 0.5 mm. The overall implant-based success rate was 96.9%, and the mean peri-implant bone loss (PBL) was 0.3 ± 0.3 mm. No statistically significant relationship was found between anatomical or clinical C/I ratio and PBL. Ultra-short implants appear to offer a predictable solution for implant-prosthetic rehabilitation in patients with edentulism and bone atrophy. A high percentage of implants were successful, with minimal crestal bone loss. The high C/I ratio did not appear to influence either peri-implant bone loss or prosthetic complication rates.

Controversies in Implant Surgery

Dental implants are a mainstream treatment protocol to replace missing teeth. Patient and clinician demands have led to shorter length and narrower diameter implants, immediately placed implants into infected sites, and the use of implants in children. This article reviews some of the controversial topics in implant dentistry, and presents the evidence that supports and challenges these newer techniques. Because long-term studies are often not available, especially for implants in infected sites, mini implants, and implants in the growing patient, the field continues to evolve.

A retrospective clinical study of single short implants (less than 8 mm) in posterior edentulous areas

PURPOSE

The goal of this study was to evaluate the clinical outcome of single short implants, less than 8 mm in length, placed in the posterior area.

MATERIALS AND METHODS

A total of 128 patients (75 male and 53 female, mean age: 52.6±11.2 years) with 154 implants participated. Implant marginal bone loss, and survival and success rates were measured.

RESULTS

The mean follow-up period was 51.35±24.97 months. A total of 128 implants, 8 mm in length, were placed in patients who had mean marginal bone loss of 0.75 mm. These implants had a survival rate of 95.3%. Twenty-six implants, 7 mm in length, were placed in areas with a mean marginal bone loss of 0.78 mm and had a survival rate of 96.2%. Both marginal bone loss and survival rate were not statistically different among the groups. In the maxilla, 34 implants showed a mean marginal bone loss of 0.77 mm and a survival rate of 97.1%. In the mandible, 120 implants showed a mean marginal bone loss of 0.75 mm and a survival rate of 95.0%. The average marginal bone loss around all implants was 0.76±0.27 mm at the last follow-up review after functional loading. The survival rate was 95.6% and success rate was 93.5%.

CONCLUSION

In our study, single short implants less than 8 mm in length in the posterior areas had favorable clinical outcomes.

Influence of implant number, length, and tilting degree on stress distribution in atrophic maxilla: a finite element study

This study aims to evaluate the stress values, created in peri-implant region as a consequence of loading on fixed hybrid dentures that was planned with different implant numbers, lengths, or tilting angulations. Thirteen three-dimensional (3D) finite element analysis models were generated with four, five, or seven implants (group A, B, and C). Except the distal implants, all implants were modeled at 4.1 mm (diameter) and 11.5 mm (length) in size. Distal implants were configured to be in five different lengths (6, 8, 11.5, 13, and 16 mm) and three different implant inclination degrees (0°, 30°, and 45°). A 150-N load was applied vertically on prosthesis. Released stresses were evaluated comparatively. The lowest von Mises stress values were found in group C, in the 11.5-mm implant model. Tilting the distal implants 30° caused higher stress values. In 45°-tilting implant models, lower stress values were recorded according to the 30°-tilting models. The ideal implant number is seven for an edentulous maxilla. Tilting the implants causes higher stress values. A 45° inclination of implant causes lower stress values according to the 30° models due to a shorter cantilever. The ideal implant length is 11.5 mm.

Short dental implants: A scoping review of the literature for patients with head and neck cancer

STATEMENT OF PROBLEM

Dental implants can be essential in the rehabilitation of various cancer defects, but their ideal placement can be complicated by the limited dimensions of the available host bone. Surgical interventions developed to increase the amount of bone are not all predictable or successful and can sometimes be contraindicated. Short dental implants have been suggested as an alternative option in sites where longer implants are not possible. Whether they provide a successful treatment option is unclear.

PURPOSE

The purpose of this study was to review the literature on short dental implants and assess whether they are a viable definitive treatment option for rehabilitating cancer patients with deficient bone.

MATERIAL AND METHODS

A scoping review of the literature was performed, including a search of established periodontal textbooks for articles on short dental implants combined with a search of PubMed, MEDLINE, EMBASE, Web of Science, and Cochrane Database of Systematic Reviews. A search for all literature published before June 2016 was based on the following keywords: ['dental implants' OR 'dental implantation, endosseous' OR 'dental prosthesis, implant supported'] AND [short].

RESULTS

The minimum acceptable implant length has been considered to be 6 mm. The survival rates of short implants varied between 74% and 96% at 5 years, depending on factors such as the quality of the patient's bone, primary stability of the implant, clinician's learning curve, and implant surface. Short implants can achieve results similar to those of longer implants in augmented bone and offer a treatment alternative that could reduce the need for invasive surgery and associated morbidity and be safer and more economical.

CONCLUSIONS

Short dental implants (6 mm to 8 mm) can be used successfully to support single or multiple fixed reconstructions or overdentures in atrophic maxillae and mandibles. The use of short dental implants lessens the need for advanced and complicated surgical bone augmentation procedures, which reduces complications, costs, treatment time, and morbidity. Short implants could be an alternative in the rehabilitation of patients with cancer.

Retrospective cohort clinical investigation of a dental implant with a narrow diameter and short length for the partial rehabilitation of extremely atrophic jaws

We investigated the short-term clinical outcomes of narrow-diameter short-length implants for the fixed-prosthetic partial rehabilitation of extremely resorbed jaws. Twenty-three patients requiring partial rehabilitations with narrow-platform short-length implants in any jaw were included in this study. In total, 30 implants 3.3 mm in diameter and 7 (n = 15 implants) or 8.5 (n = 15 implants) mm in length were inserted. The primary outcome measure was implant cumulative survival rate (CSR); the secondary outcome measures were marginal bone resorption at 1 and 3 years and the incidence of biologic and mechanical complications. Five patients (21.7%) with six implants (20%) were lost to follow-up. Two implants failed in two patients, yielding a CSR at 3 years of follow-up of 93.4%. The average (standard deviation) marginal bone resorption was 1.34 mm (0.95 mm) after the first year and 1.38 mm (0.78 mm) after the third year. Biologic complications occurred in three patients; mechanical complications occurred in three patients. Despite the limitations of the study, our findings show that the use of new narrow-diameter short-length implants for the rehabilitation of extremely atrophic regions is viable in the short-term, and can be considered a treatment alternative in extremely resorbed jaws.

The all-on-4 modified polyetheretherketone treatment approach: A clinical report

A modified polyetheretherketone (PEEK) implant framework material in combination with prefabricated high-impact poly(methyl methacrylate) (PMMA) veneers was used as an alternative material for the fabrication of a complete maxillary arch implant-supported fixed restoration. The elastic performance of the PEEK framework (elastic modulus of 4 GPa) combined with PMMA veneers may reduce the occlusal forces, protecting the implant-supported restoration and the opposing dentition, especially in all-on-4 treatments, where lack of proprioception and wide interimplant distance are present. Long-term clinical evidence is required before recommending the application as an alternative restorative material for such a prosthesis.

Minimizing the discrepancy between implant platform and alveolar bone for tilted implants with a sloped implant platform: A clinical report

In a patient with edentulism, distally tilted implants with a novel sloped implant platform were used to minimize the discrepancy between the implant platform and alveolar bone crest and to restore complete-arch monolithic zirconia implant-supported fixed prostheses.

Management of Limited Vertical Bone Height in the Posterior Mandible: Short Dental Implants Versus Nerve Lateralization With Standard Length Implants

Inferior alveolar nerve lateralization (IANL) and short dental implants (SDI) are 2 viable implant-based treatment approaches in the presence of atrophied posterior mandible. Despite the risks of dysfunction, infection, and pathologic fractures in IANL, it becomes possible to place standard implants. The purpose of this study was to compare SDI and IANL approaches from clinical and radiographic aspects. Fifteen subjects having unilateral atrophic mandibles were allocated to SDI and IANL treatment groups. Following surgical procedures, early postoperative complications, implant survival, and periimplant clinical and radiographic parameters including probing pocket depth, attachment level, keratinized tissue amount, vertical tissue recession, and marginal bone loss were recorded at baseline and 1-year after prosthetic rehabilitation. In both groups, no implant was lost. Except usual postoperative complications, 2 patients had transient paraesthesia after IANL. According to time-dependent evaluation, both groups showed significant increase in probing pocket depth and attachment level at 1-year follow-up compared with baseline (P < 0.05). Except a slight but significant increase in mesial surface of SDI group (P < 0.05), no remarkable time-dependent change was identified in vertical tissue recession. Keratinized tissue amount did not exhibit any inter- or intragroup difference during whole study period. Marginal bone loss did not show any difference between IANL and SDI groups at follow-up. SDI placement or standard length implant placement with IANL can be considered promising alternatives in the treatment of atrophic mandibular posterior regions. However, SDI may be preferred in terms of lower complication risk.

The influence of initial alveolar ridge defect morphology on the outcome of implants in augmented atrophic posterior mandible: an exploratory retrospective study

OBJECTIVES

Clinicians commonly consider atrophic site topography as an important determinant in deciding the augmentation technique to utilize, as well as forecasting the likelihood of success. The purpose of this retrospective study was to examine the influence of initial atrophic posterior mandible morphology on the outcome of implants placed following augmentation.

MATERIALS AND METHODS

A total of 52 patients contributed 71 edentulous sites, and 185 implants were placed with mean follow-up of 37.97 months. The initial defect morphology was classified according to ABC classification (Journal of Oral Implantology, 37, 2013a and 361). Ridge augmentation was performed by "cortical autogenous tenting" (CAT) followed by either simultaneous or delayed implant placement after 4-6 months of healing. The European Academy of Osseointegration success criteria were used to evaluate implant outcomes.

RESULTS

The overall survival and success rates of dental implants were 98.91% and 80%, respectively. Cumulative success and survival rates in CAT group were 95% and 100% after 2 years of follow-up. The highest marginal bone loss (MBL) was observed (1.26 mm ± 0.99) around implants placed in augmented edentulous sites with initially narrow and flat alveolar crest (defect class CII). Conversely, least MBL (0.48 mm ± 0.78) was detected around implants placed into edentulous sites with two sloped boney walls (defect class AII). Differences between MBL observed around implants placed into initial defect class C, initial defect type and class A (I, II), as well as class BII, were statistically significant (P < 0.05). Among all implants, 148 were considered as successful, 26 exhibited satisfactory survival, nine with compromised survival, and two implants failed.

CONCLUSION

The present data confirmed the effect of initial ridge morphology on the outcome of implants placed into augmented bone. Specifically, class A and class B atrophic ridge defects, with one and two vertical boney walls, respectively, may be considered as more favorable recipient sites than class C defects with flat morphology. This conclusion is based on least MBL around implants placed into initial defect class A and class B augmented sites, and higher MBL in implants placed into class C recipient sites. A randomized controlled trial is warranted to examine these exploratory observations.

Biomechanical analysis of immediately loaded implants according to the "All-on-Four" concept

PURPOSE

The purpose of this study was to investigate the biomechanical behavior of immediately loaded implants in an edentulous mandible according to the "All-on-Four" concept.

METHODS

A 3D-finite element model of an edentulous mandible was constructed. Four implants were placed between the bilateral mental foramen according to "All-on-Four" concept. A framework made of titanium or acrylic resin between the bilateral first molars was modeled. Immediate loading and a delayed loading protocol were simulated. A vertical load of 200N was applied at the cantilever or on the abutments region of the distal implants, simulating the absence of a cantilever.

RESULTS

The peak principal compressive strains in the immediate loading models resulted in 24.0-35.8% and 26.4-39.0% increases compared with the delayed loading models under non-cantilever loading and cantilever loading, respectively. The loading position greatly affected the principal compressive and tensile strain values. The peak principal compressive strains in non-cantilever loading resulted in a 45.3-52.6% reduction compared with those in cantilever loading. The framework material did not influence the peak compressive and tensile strain. The maximum micromotion at the bone-implant interface in the immediate loading models was 7.5-14.4μm.

CONCLUSIONS

Mandibular fixed full-arch prostheses without cantilevers may result in a favorable reduction of the peri-implant bone strain during the healing period, compared with cantilevers. The maximum micromotion was within the acceptable limits for uneventful implant osseointegration in the immediate loading models. Framework material did not play an important role in reducing the peri-implant bone strain and micromotion at the bone-implant interface.

Dental Implant Length and Diameter: A Proposed Classification Scheme

PURPOSE

To propose a length-and-diameter-based classification scheme for dental implants to standardize terminology in the dental literature and communication between interested parties.

MATERIALS AND METHODS

This study was mainly based on searching two major resources: published scientific research papers and 14 of the most popular dental implant manufacturers. Indexed databases were searched from January 2004 up to and including February 2016 using the keywords "dental implant length" and "dental implant diameter." Retrieved titles and abstracts were screened, and related full-text articles were reviewed. Full-text articles that clearly stated the terms and measurements of implants used were included and considered for proposing this classification scheme.

RESULTS

The initial search for implant diameter and length yielded 1007 and 936 articles, respectively. A total of 85 studies (41 about diameter, 44 about length) were selected and reviewed. The remaining studies (966 about diameter, 892 about length) that did not abide by the eligibility criteria were excluded. The terms "long," "short," "standard," "wide," and "narrow" were the most commonly used terms in the literature. A classification scheme for implants by diameter and length was proposed.

CONCLUSIONS

Indexed publications contain a variety of terms used by authors to describe diameter and length of dental implants without conformity and standardization. The classification scheme proposed in this article could serve as a reference for interested parties.

Does increasing the number of short implants reduce marginal bone loss in the posterior mandible? A prospective study

Marginal bone loss is a concern in the long-term prognosis of short dental implants. The aim of this prospective cohort study was to evaluate the loss when variable numbers of short implants were used in the posterior mandible. The subjects were allocated into three groups according to the number of short implants. The first group was given two, the second three, and the third four. Each patient had radiographs taken immediately after loading and repeated 36 months later. Twenty- three subjects with 65 implants were entered in the three groups. The mean (SD) marginal bone loss was 0.49 (0.04) mm in the two implant group, 0.41 (0.25) mm in the three implant group, and 0.35 (0.25) mm in the four implant group. There were significant differences in marginal bone loss among the three groups (p=0.001), in that the fewer the number of short implant-supported fixed prostheses in the posterior mandible, the greater the marginal bone loss. When we used more short implants the amount of marginal bone loss decreased.

Comparative Finite Element Analysis of Short Implants and Lateralization of the Inferior Alveolar Nerve With Different Prosthesis Heights

The lateralization of the inferior alveolar nerve (LIAN) and short implants are efficient options for rehabilitation of the posterior atrophic mandible. However, the loss of bone leads to prosthesis with greater height and lever effect that in turn can have different impact on treatments. Through the finite element method, the present study tests the hypothesis that conventional implants placed under LIAN and short implants have similar risk of bone loss regarding variable height of the crown and that crown-to-implant ratio is not a reliable resource to evaluate risk in these treatments. Computed tomography scans of mandibles were processed and implants and prosthetic components were reverse engineered for reconstruction of three-dimensional models to simulate 3 elements fixed partial dentures supported by 2 osseointegrated implants. The models of implants were based on MK III implants (Nobel Biocare, Zurich, Switzerland) with 4 mm in diameter by 7 mm in length representing short implants, and 15 mm in length representing implants used in LIAN. The implant/crown ratio for short implants was 1:1.5, 1:2, and 1:2.5 and LIAN models were modeled with exactly the same prosthesis, resulting in implant/crown ratios of 1:0.67, 1:0.89, and 1:1.12. The results partially rejected the hypothesis that LIAN and short implants have similar risk of bone loss, showing that although LIAN results were better in the models evaluated, the variations in height had proportionally similar impact on both treatments and accepted the hypothesis that crown-to-implant ratio was not a reliable resource to evaluate risk.

Evaluation of extrashort 4-mm implants in mandibular edentulous patients with reduced bone height in comparison with standard implants: a 12-month results

OBJECTIVE

The aim of this research was to evaluate the primary stability, the marginal bone loss, the survival, and the success criteria, of 4-mm-length implants compared with implants of conventional length supporting fixed prostheses.

MATERIALS AND METHODS

Ten patients were selected for treatment of their atrophic edentulous jaws. Each patient received the following treatment: six dental implants were inserted, two anterior implants of conventional length (10-mm) in the interforaminal area and four posterior short implants of 4-mm length (Standard Plus, Roxolid, SLActive, Institut Straumann AG). The implants supported screw-retained fixed complete dentures. Examinations were conducted at day 0, three, six, and twelve months after surgery for the evaluation of the implant primary stability, secondary stability, crestal bone loss and survival by clinical evaluations, insertion torque values, resonance frequency analysis (RFA), and periapical radiography, respectively.

RESULTS

Sixty implants were inserted in ten patients. Mean insertion torque was slightly lower for 4-mm implants than 10-mm implants (38.1 Ncm vs. 42.2 Ncm) but without statistically significant difference. Implant stability was similar for extrashort and conventional implants. Marginal bone loss was similar for both groups for all the time periods. One short implant was lost before loading. The survival rates twelve months after implant placement were of 97.5% and 100% for short and conventional implants, respectively. Similarly, implant stability as measured by RFA was nonsignificantly lower for the 4-mm implants compared to the 10-mm implants. The marginal bone loss was lower for short implants three, six, and twelve months after the surgery without statistical significant difference.

CONCLUSIONS

Within the limitations of this study, we conclude that short dental implants (8 mm or less in length) supporting single crowns or fixed bridges are a feasible treatment option with radiographic and clinical success rates similar to longer implants for patients with compromised ridges. Long-term data with larger number of implants and subjects are needed to confirm these preliminary results.

Survival rate of short, locking taper implants with a plateau design: a 5-year retrospective study

Background. Short implants have become popular in the reconstruction of jaws, especially in cases with limited bone height. Shorter implants, those with locking tapers and plateau root shapes, tend to have longer survival times. We retrospectively investigated the cumulative survival rates of Bicon short implants (<8 mm) according to patient variables over a 5-year period. Materials and Methods. This study included 111 consecutively treated patients with 371 implants supporting fixed or removable prosthetics. Data were evaluated to acquire cumulative survival rates according to gender, age, tobacco use, surgical procedure, bone quality, and restoration type. Statistics were performed using chi-square, Mann-Whitney, and Kruskal Wallis H tests. Results. The survival rate was 97.3% with, on average, 22.8 months of follow-up. Patients older than 60 years had higher failure rate than the other age groups (P < 0.05). Placed region, age, and bone quality had adverse effects on survival rate in the <8 mm implant group with statistically significant difference (P < 0.05). Conclusions. Approximately 23-month follow-up data indicate that short implants with locking tapers and plateau-type roots have comparable survival rates as other types of dental implants. However, due to limitations of study, these issues remain to be further investigated in future randomized controlled clinical trials.

Immediate loading short implants inserted on low bone quantity for the rehabilitation of the edentulous maxilla using an All-on-4 design

More studies evaluating the outcome of short-length dental implants in immediate loading are needed. To evaluate the use of short-length tapered implants in immediate loading for complete edentulous maxillae rehabilitations using an All-on-4 design. This retrospective clinical study included a cohort of 43 patients with 172 implants (74 short-length implants) inserted in low bone quantity. The patients were followed between 4 months and 6 years (average = 3 years). Outcome measures were implant survival, marginal bone remodelling, biological and mechanical complications. Two patients with four short-length implants were lost to follow-up during the first year. Three short and three long implants failed in four patients, rendering an overall cumulative survival rate implant and patient level, respectively, of 95.7% and 95.1% for short implants, 100% for regular implants and 96.6% and 95.2% for long implants. The average marginal bone remodelling at 1 and 3 years was 0.97 and 1.25 mm for the short implants, 0.82 and 0.87 mm for regular implants and 0.87 and 0.98 mm for long implants. Three patients presented 4 short-length implants with peri-implant pockets (3 implants in 2 patients were pseudo-pockets). Mechanical complications were registered in 13 patients (7 provisional prostheses fractures and 6 abutment screw loosening). All complications were treated successfully. Within the limitations of this clinical study, the short-term outcome of fixed prosthetic complete edentulous maxillae rehabilitations supported by short-length implants inserted in low bone quantity areas is viable. Long-term clinical studies are necessary for evaluating the outcome of these implants.

Posterior maxillary implants inserted with bicortical anchorage and placed in immediate function for partial or complete edentulous rehabilitations. A retrospective clinical study with a median follow-up of 7 years

PURPOSE

The aim of this study was to report the outcome of posterior maxillary implants inserted with "bicortical anchorage" in medium or low-density bone and placed in immediate function for the rehabilitation of patients with partial or complete edentulism.

METHODS

Eighty-eight patients (32 males and 56 females, mean age = 54 years; range 28-78 years) were included from October 1999 to November 2008, and followed between 6 months and 13 years (median of 7 years). A total of 124 posterior maxillary implants were inserted with bicortical anchorage (engaging the cortical plates of the maxillary crest along with that of either the sinus or nasal cavities) as follows: MkII (n = 1), MkIII (n = 6), MkIV (n = 18), and NobelSpeedy Groovy (n = 99); (Nobel Biocare AB). Implants were evaluated on the basis of survival, marginal bone levels, and complications (mechanical and biological).

RESULTS

Eleven patients dropped out of the study (12.5 %). Four implants were lost in four patients who underwent complete edentulous rehabilitations, yielding a cumulative survival rate of 94.2 % after a median follow-up of 7 years. The survival rate for the prostheses was 100 %. The marginal bone levels were on average 1.56 mm (standard deviation of 0.87 mm), after 5-years of follow-up. Biological complications occurred with 17 implants in 17 patients. Mechanical complications occurred in 49/88 patients. Thirty of these 49 patients were heavy bruxers.

CONCLUSIONS

Within the limitations of this study, fixed prosthetic rehabilitations for partial and complete edentulism supported by implants in the posterior maxilla which are inserted with bicortical anchorage and placed in immediate function is a viable concept on long-term follow-up. Nevertheless, controlling the occlusion is mandatory in order to decrease the likelihood of mechanical complications.

Complete arch site classification for all-on-4 immediate function

Complete arch immediate function of dental implants requires a treatment protocol that takes advantage of residual areas of cortical bone for the apical fixation of implants. A site and jaw bone classification is proposed that has been in use since 2006 for all stages of atrophy for both jaws. The use of the classification is strictly for immediate function based on specific cortical bone sites in the facial skeleton to assist practitioners in diagnosis, treatment planning, and interdisciplinary communication, as well as to reduce human error in patient management. A recent series of 100 consecutive arches that were treated according to this classification is presented.

In selected sites, short, rough-surfaced dental implants are as successful as long dental implants: a critical summary of Pommer B, Frantal S, Willer J, Posch M, Watzek G, Tepper G. Impact of dental implant length on early failure rates: a meta-analysis of observational studies. J Clin Periodontol 2011;38(9):856-863

CLINICAL QUESTION

In adult patients, do short dental implants (< 10 millimeters) lead to failure rates similar to those for longer implants (≥ 10 mm) in the first year of loading?

REVIEW METHODS

Two independent reviewers searched three electronic databases and 29 journals for articles published from January 1998 to January 2008. The authors included in the review only English-language, prospective observational studies in which the allocation decision occurred in the course of usual treatment. Also, implants must have been placed in nonaugmented healed jawbone after a conventional healing period of three to six months. The primary outcome measured was implant failure within the first year of prosthetic loading, determined on the basis of established criteria.1 A meta-analysis was carried out in which the authors compared the association between implant length and failure. In addition, the authors performed subgroup analyses of failure as a function of the implants’ diameter, surface texture and location in the maxillary or mandibular arch.

MAIN RESULTS

Fifty-four trials, including 19,563 dental implants (with only a 2.4 percent dropout rate), met the inclusion criteria. The results of the meta-analysis, which consisted of 40 studies (2,223 short implants and 14,158 long implants), showed that shorter implants had an overall failure rate statistically significantly higher than that for long implants within the first year of loading (odds ratio [OR] = 1.8; 95 percent confidence interval [CI], 1.3-2.5). The results of subgroup analyses showed a statistically significant difference in failure rates for short and long implants in the maxilla, but no difference in the mandible. However, with the possible exception of the anterior maxilla, the failure rates for rough surfaced implants in the two groups (1,298 short implants and 7,544 long implants) were not statistically significantly different (OR = 1.1; 95 percent CI, 0.6-2.1). The authors found no association between implant diameter and failure rates within one year of prosthetic loading.

CONCLUSIONS

With the possible exception of the maxillary anterior area, rough-surfaced short implants with a minimum length of 7 mm present no additional risk of failure within the first year of loading.

Systematic review of the survival rate and the incidence of biological, technical, and aesthetic complications of single crowns on implants reported in longitudinal studies with a mean follow-up of 5 years

OBJECTIVE

To assess the 5-year survival of implant-supported single crowns (SCs) and to describe the incidence of biological, technical, and aesthetic complications. The focused question was: What is the survival rate of implants supporting single crowns and implant-supported crowns with a mean follow-up of 5 years and to which extent do biological, technical, and aesthetic complications occur?

METHODS

A Medline search (2006-2011) was performed for clinical studies focusing on implant-supported SCs with a mean follow-up of at least 5 years. The search was complemented by an additional hand search and the inclusion of 24 studies from a previous systematic review (Jung et al. 2008a). Survival and complication rates were analyzed using random-effects Poisson's regression models to obtain summary estimates of 5- and 10-year proportions.

RESULTS

Forty-six studies derived from an initial search count of 1083 titles and the complementary publications from the previous systematic review (Jung et al. 2008a) were selected and the data were extracted. Based on the meta-analysis, survival of implants supporting SCs at 5 years amounted to 97.2% (95% CI: 96.3-97.9%), and at 10 years amounted to 95.2% (95% CI: 91.8-97.2%). The survival of implant-supported SCs was 96.3% (95% CI: 94.2-97.6%) after 5 years and 89.4% (95% CI: 82.8-93.6%) after 10 years. For biological complications, a 5-year cumulative soft tissue complication rate of 7.1% (95% CI: 4.4-11.3%) and a cumulative complication rate for implants with bone loss >2 mm of 5.2% (95% CI: 3.1-8.6%) were calculated. Technical complications reached a cumulative incidence of 8.8% (95% CI: 5.1-15.0%) for screw-loosening, 4.1% (95% CI: 2.2-7.5%) for loss of retention, and 3.5% (95% CI: 2.4-5.2%) for fracture of the veneering material after 5 years. The cumulative 5-year aesthetic complication rate amounted to 7.1% (95% CI: 3.6-13.6%).

CONCLUSIONS

The outcomes of the meta-analysis demonstrated high implant survival rates for both the single tooth implants and the respective single crowns after 5 and 10 years. However, technical, biological, and aesthetic complications were frequent.

One-Year Prospective Study of 7-mm-Long Implants in the Mandible: Installation Technique and Crown/Implant Ratio of 1.5 or Less

This study prospectively evaluated the clinical prognoses of short implants (7-mm long) in the mandible. We investigated the clinical prognosis of short implants in 20 patients (46 implants) according to the installation technique (submerged or nonsubmerged), installation depth (5.5-mm depth, 7-mm depth), and crown/implant ratio. We investigated the marginal bone loss and peri-implant soft-tissue index 12 months after the final prosthetic delivery. Twelve months after prosthetic delivery, no statistically significant differences were observed in bone loss in relation to the type of installation technique, installation depth, or crown/implant ratio. The plaque index and pocket depth indexes were not influenced by the installation technique, installation depth, or crown/implant ratio. We observed marginal bone loss of 3.3 mm in 1 implant from the nonsubmerged group. The total 1-year success rate was 97.83%. Based on this 1-year success rate, short implants had a good clinical prognosis, regardless of the installation technique, installation depth, or crown/implant ratio.

Short dental implants in reduced alveolar bone height: a review of the literature

Background

The purpose of this study was to evaluate the use of short dental implants in distally reduced alveolar bone height.

Material/Methods

MedLine (PubMed and Ovid), ISI Web of Knowledge, and Cochrane databases were used for analysis. Searching was conducted using the search equation: ‘Dental Implants’ [Majr] AND (Short[TIAB] OR Shorter[TIAB]) AND (Implant[TIAB] OR Implants[TIAB]). Abstracts were screened by 2 independent reviewers. The articles included in the analysis were published in the English language and reported data on the use of implants with lengths below 10 mm in the posterior region with reduced alveolar bone height making the placement of longer implants impossible without additional surgical interventions. Articles concerning data on orthodontic implants and post-resection surgery reconstruction were excluded from analysis. Any disagreements between the 2 reviewers were resolved by a third reviewer. No time frame was used.

Results

Of the 791 articles initially found, automatic rejection of duplicates in the Endnotes X5 software resulted in 538 articles. After the selection of studies from databases, a bibliography of 32 eligible articles was searched for other publications. Through this method, 2 more studies were added.

Conclusions

The analysis of the results of different studies on the use of short dental implants showed that this treatment could be effective and comparable to the use of standard-length implants. This study revealed that rough-surfaced implants with lengths between 6–10 mm placed in the posterior mandible are the preferred solution. However, more detailed data will require additional prospective studies.

Preliminary report on the outcome of tilted implants with longer lengths (20-25 mm) in low-density bone: one-year follow-up of a prospective cohort study

PURPOSE

The aim of this preliminary study was to report on the short-term outcome of tilted implants with 20 to 25 mm of length in immediate function with bicortical anchorage for prosthetic rehabilitation of complete edentulous jaws with low-density bone.

MATERIAL AND METHODS

Sixteen patients (with 25 study implants and 43 nonstudy implants) presenting low-density bone were included in a prospective single cohort study to evaluate the short-term outcome of partial and complete edentulous rehabilitations using implants with 20 to 25 mm of length (NobelSpeedy Groovy, Nobel Biocare AB, Gothenburg, Sweden) in immediate function with bicortical anchorage (maxilla: alveolar ridge and nasal corticals; mandible: mandibular corticals). The patients were followed between 6 and 26 months (average of 14 months). Outcome measures were implant survival, marginal bone remodeling, biological and mechanical complications assessed at 10 days, 2, 4, and 6 months, 1-year posttreatment, and thereafter every 6 months.

RESULTS

Two patients with four implants were lost to follow-up after 6 and 11 months. There were no implant failures, rendering a cumulative implant survival rate of 100%. The average marginal bone remodeling was 0.50 mm (SD = 0.34 mm) and 0.86 mm (SD = 0.46 mm), after 6 months and 1 year, respectively. There was one mechanical complication in one patient (abutment loosening) 1 month post-surgery.

CONCLUSION

Within the limitations of this study, the short-term outcome of prosthetic rehabilitations of patients with low-density bone using implants of 20 to 25 mm in length in immediate function with bicortical anchorage is viable judging by the high implant survival rate, low marginal bone remodeling, and low incidence of complications. Long-term evaluation of these implants through studies using a prospective design is mandatory.

Survival and complications of zygomatic implants: a systematic review

PURPOSE

This systematic review attempted to answer the focused questions: "What is the survival rate of zygomatic implants (ZIs)?" and "What are the most common complications related to surgery of zygomatic implants?"

METHODS

An electronic search without date or language restrictions was undertaken in PubMed in March 2012. Titles and abstracts from these results (n = 123) were read for identifying studies that meet the eligibility criteria. Eligibility criteria included studies reporting clinical series of zygomatic implants (ZIs). Because of the scarcity of articles with high-level grades of evidence, all articles, including studies with few case reports, were considered for inclusion. All reference lists of the selected and review studies were hand-searched for additional papers that might meet the eligibility criteria. Simple case report articles were not included. Review articles without original data were excluded. Quantitative data extracted from the included studies that provided data for the period of failure of ZIs were used for the calculation of interval survival rate during each follow-up period and cumulative survival rate (CSR) over a 12-year period.

RESULTS

Thirty-seven studies were identified without repetition and five more studies were included by hand-searching, giving a total of 42; 12 evaluated the use of ZI applied with immediate function protocols and 3 for rehabilitating patients after maxillary resections for tumor ablations. These latter three studies showed smaller ZI success. Postoperative complications reported were as follows: 70 cases of sinusitis, 48 of soft tissue infection, 15 of paresthesia, and 17 cases of oroantral fistulas. However, this number may be underestimated, since most of the studies did not mention the presence or absence of these complications. Most ZI failures were detected at the abutment connection phase (6 months after the surgery of implant placement) or before. The CSR over a 12-year period was 96.7 %.

CONCLUSIONS

Despite the high survival rate observed, there is an impending need for conducting randomized controlled clinical trials to test the efficacy of these implants in comparison with the other techniques to treat the atrophic maxilla. Thus, the findings reported in the review must be interpreted with considerable caution. Moreover, more studies with longer follow-up periods involving adequate number of ZIs are needed. This will help to obtain a better understanding of the survival of ZIs in a long term. It is suggested that multicenter, randomized controlled clinical trials and longer clinical studies should be implemented in this area, before recommending routine use of ZIs for patients could be given. The placement of zygomatic implants requires very experienced surgeons because it is not risk free since delicate anatomic structures such as the orbita and brain may be involved.

The inlay osteotome sinus augmentation technique for placing short implants simultaneously with reduced crestal bone height. A short-term follow-up

OBJECTIVE

To display an inlay technique of osteotome sinus floor elevation using a trephine combined with simultaneous short implant placement where the residual bone height (RBH) is less than 5 mm, as well as to evaluate the clinical effect in a prospective study.

MATERIAL AND METHODS

Fifty short implants were installed in 32 patients in the severely atrophic posterior maxilla immediately after sinus floor elevation between January 2010 and October 2012. An inlay osteotome sinus augmentation technique using a trephine was applied in the operation. The mean residual bone height adjacent to or beneath the sinus was 3.34 mm, ranging from 0.96 mm to 4.96 mm. It was rarely necessary to add graft material from bovine sources in this therapy. With the purpose of bite training and soft tissue reforming, the temporary crowns were fixed after 6 months. The final prostheses were restored 3 months later. The stability and osseointegration of the implants were clinically evaluated, also the bone height gain around the implants was measured.

RESULTS

The survival rate was 100% during the study period with this procedure. Each of the implants, loaded without pain or any subjective sensation, was clinically stable. No implants had detectable sinus membrane perforation during operation. The radiographic results demonstrated that the bone height gain was 5.38 mm after the surgery.

CONCLUSION

Based on the results and within the limits of the present study, it can be suggested that short implant placement in conjunction with this inlay osteotome sinus augmentation technique could yield predictable clinical results for edentulous posterior maxillary region with RBH less than 5 mm. Besides, from the clinical point of view, these techniques may reduce the indication for complex invasive procedures and simplify treatment in the posterior.