Clinical study on survival rate of short implants placed in the posterior mandibular region: resonance frequency analysis

Prosthetic Applications of Short Dental Implants in Limited Bone Height Cases: A Review Article

The decision to rehabilitate insufficient alveolar bone height with short implants is considered an effective treatment. Complicated surgical procedures such as ridge augmentation, vestibuloplasty, and sinus lifting are usually accompanied by high risks such as membrane injury, hemorrhage, nerve affection, and increased time needed for implant treatment with unpredictable healing time. Short dental implants allow for faster treatment and decrease the need for complicated surgeries that are usually associated with standard dental implants, as in all four and all six concepts. A wide variety of short implants for replacing single, multiple, or even prosthetic rehabilitation of completely edentulous patients, either by using hybrid or overdenture prostheses, were documented by several studies. Further clinical investigations are needed to evaluate the improvement of short implant survival rate, the possibility of using short implants for patients with normal ridge height and contour, and also for patients who need maxillofacial prostheses.

Long-term effectiveness of UV functionalised short (≤ 6 mm) dental implants placed in the posterior segments of the atrophied maxilla: controlled case series

This study evaluated long-term effectiveness UV functionalised short implants (≤ 6 mm) placed in the posterior segments of the atrophied maxilla. The study included 47 patients from 2018 to 2023 (aged 27 to 56 years, 24 women and 23 men) without any systemic diseases, with unilateral/bilateral missing teeth and vertical atrophy of the posterior maxillary area. Total installed were 64 short UV-functionalized implants and 62 standard implants over 10 mm in length in segments maxilla with sufficient bone parameters. Clinical, laboratory and cone beam computed tomography (CBCT) methods were used to plan implant therapy. The clinical indices included the following parameters: ISQ, MBL, OHIP-G scale. For short implants, the median ISQ at placement was 62.2 for primary stability and the median ISQ at 5 months was 69.6 ISQ. For standard implant, the mean ISQ at placement was 64.3 ISQ, and ISQ after 5 months was 71.6 ISQ. After 6 months mean MBL short implants 0.87 mm, after 1 year 1.13 mm, after 5 years was 1.48 mm. After 6 months mean MBL standard implants 0.84 mm, after 1 year 1.24 mm, after 5 years was 1.58 mm. Mean OHIP-G scores-patients satisfaction with the implant at 4.8 ± 0.3, satisfaction with the operation 4.6 ± 0.4; satisfaction with prosthetics 4.7 ± 0.5. Cumulative success rate 5 years short implants was 96.7%, standard implants was 97.4%, and prosthesis cumulative survival rate was 97.2%. Short ultraviolet functionalized implants used in the posterior resorbed segment of maxilla have been shown to be a reliable alternative to sinus lift, demonstrating fewer complications, reduction in the number of additional surgical interventions and showed satisfactory long-term survival.

A naïve comparison to assess the success of ultra-short implants

Introduction

Conventional implants are associated with ridge augmentation/sinus lift procedures in vertically insufficient ridges, which increase morbidity and healing time. Short implants provided some hope in this context. The present study considered the use of ultra-short implants in vertically insufficient posterior mandibular ridges and evaluated their success. Hence, study was done to evaluate the success of ultra-short implants in partially edentulous posterior mandible clinically and radiographically.

Materials and Methods

The study is a "Naïve direct comparison" of ultra-short implants to conventional implants for assessing their success in vertically insufficient posterior mandibular ridges. A total of 10 ultra-short implants were placed in a partially edentulous posterior mandibular ridge with at least 8-mm horizontal (at crest) and vertical dimensions. A delayed loading was done at three-month follow-up. Data acquisition was done at baseline (immediately after loading), 6-, 9-, 12-month intervals. Parameters assessed were marginal bone loss (MBL), probing pocket depth reduction (PPDR), modified plaque index (mPI), modified gingival index (mGI).

Results

All the placed 10 implants survived, and no failure was observed. "Independent sample t-test" and "paired sample t-test" was done for intergroup and intragroup analysis, respectively. Intergroup comparison between the ultra-short and conventional implants presented a statistically insignificant difference between all the parameters at all the follow-up visits (baseline, 6-, 9-, 12 months).

Conclusions

Within the limitations, it was thus concluded that ultra-short implants may be considered as a viable treatment option for vertically insufficient mandibular ridge. Further, long-term randomized controlled trials are required to establish the evidence.

Rehabilitation of distal extension maxillary ridges with fixed and removable implant-supported prostheses: Preliminary 12-month randomized clinical trial

PURPOSE

This trial evaluated clinical outcomes of fixed and removable implant-supported prostheses for rehabilitation of atrophied distal extension maxillary ridges.

MATERIALS AND METHODS

A total of 54 participants with atrophied distal extension maxillary ridges were randomly assigned into three groups (n = 18/group). Group I (SLF); participants treated with fixed restoration supported by three long implants after sinus augmentation, Group II (SF); participants treated with fixed restoration supported by one long and two short implants, and Group III (OD): participants treated with removable partial denture assisted by one long implant that was placed mesial to maxillary sinus (IARPD). Modified plaque index (MPI), modified gingival index (MGI), pocket depth (PD), implant stability (IS), and crestal bone loss (CBL) were measured after prosthesis insertion (T0), 6 (T6), and 12 months (T12) after insertion. Patient satisfaction was measured at T12 using a visual analog scale (VAS).

RESULTS

The implant survival rates were 96.8%, 92.4%, and 84.6% for SLF, SF, and OD groups respectively. The SLF recorded the highest MPI, MGI, PD, and IS values, followed by the SF, and the OD showed the lowest values. The OD recorded the highest CBL followed by the SF and the SLF showed the lowest CBL. With exception of satisfaction with surgery and cleaning, SLF and SF groups recorded significantly higher patient satisfaction than the OD for all VAS questions.

CONCLUSION

Fixed restorations supported with either long or short implants were associated with improved implant stability, reduced bone loss, and increased patient satisfaction compared to implant-assisted RPDs. However, implant-assisted RPDs were associated with more favorable peri-implant soft tissue health and increased satisfaction with surgery, healing, and cleaning.

Clinical Outcome of Immediate Loading UV-Photofunctionalized Implants in Patients with Completely Edentulous Mandible, Placed with Guided Surgery

Objectives

The purpose of this study was to evaluate clinical results of immediate loading UV-photofunctionalized dental implants placed using guided surgery in patients with completely edentulous mandible.

Material and Methods

In this study, 58 fully edentulous patients were treated with immediate loading implant-supported mandibular prostheses. All patients underwent a thorough clinical examination according to the generally accepted scheme; qualitative and quantitative parameters of the jaw bones patients were diagnosed with cone beam computerized tomography (CBCT). Surgical templates modeled in the 3 Shape software were made from biocompatible polymeric materials and provided with depth-calibrated drill sleeves for preparing osteotomies using a 3D printer (Stratasys). Before short implant placement, ultraviolet functionalization of implant surfaces was performed by UV Activator YWJ-QSY001 (Foshan, Wenjian Medikal Enstriman) in the device for 20 s. After flapless surgery, implant sockets were prepared with guided surgery and implants were placed through the sleeves of the surgical template tightening torque of 35-45 Ncm. An implant-supported temporary prosthesis made of acrylic resin was installed 6 h after implantation. Final dental prosthetics was performed 2 months after implant placement.The patients had 128 short (length 5-6 mm, diameters 4,5-5 mm) and 256 implants with length greater than 10 mm in bone segments with sufficient bone parameters. The following parameters were assessed: implant success, prosthetics survival and changes in peri-implant marginal bone loss (MBL).

Results

During a clinical examination, no serious biological or prosthetic complications have been reported. The esthetic result evaluated from patients was excellent. The mean ISQ of short implants was 69.2 ± 8 for primary stability at implant placement and 73.6 ± 4 ISQ after 3 months. The mean of implants with length greater than 10 mm was 71,2ISQ at implant placement, respectively, and 75,6 ISQ after 3 months. After 3 months of prosthetic loading for short implants marginal bone loss (MBL) 0.74 mm, after 1 year of MBL 11.21 mm, after 5 years of MBL 1,37 mm, for implants with length greater than 10 mm after 3 months of MBL 0.72 mm, after 1 year of MBL 1.19 mm and after 5 years of MBL 1.35. There was no statistically significant difference in clinical indices between short and standard implants. After 5 years of follow-up, stable levels of bone tissue around the implants and healthy tissues around the implants were recorded, and postoperative occlusal function was favorable. The success rates of the short implants in maxilla were 95.5%, and the success rates of the short implants in mandible were 98.7%. The success rates of the implants with length greater than 10 mm in maxilla were 97.8%, and the success rates of the implants with length greater than 10 mm in mandible were 98.8%.

Conclusion

Computer-guided implant surgery and immediate loading of UV-photofunctionalized implants in patients with completely edentulous mandible are a predictable and effective method with a minimum rehabilitation period.

Comparative Evaluation of Implants with Different Surface Treatments Placed in Human Edentulous Mandibles: A 1-Year Prospective Study

The aims of this study were to analyze prospectively and comparatively the peri-implant bone crest levels, bone density, stability and success rate of implants with different surface treatments in human edentulous mandibles. Twenty edentulous patients were selected. Four different implants were placed between the mental foramen. Four groups were evaluated: (1) laser-modified surface (LASER), (2) surface modified by laser with deposition of apatites (LASER + HA), (3) surface modified by double acid etching (ACID, Implacil De Bortoli) and (4) surface modified by sandblasting and acid etching (SLActive®, Straumann). Clinical, radiographic, resonance frequency and tomographic analyses were used. After 4 months, mandibular fixed implant prostheses were installed. Clinical and radiographic analyses were performed at times T0 (immediately after implant placement), T1 (15 days), T2 (30 days), T3 (60 days), T4 (90 days), T5 (120 days), T6 (180 days) and T7 (360 days), post-implant placement. The resonance frequency analysis (RFA) was measured at T0, T4, T6 and T7. The tomographic analysis was performed at T0, T4 and T7. In the radiographic bone density analysis, a statistical difference was found between the SLActive® and LASER + HA groups at T4 (p < 0.05). Statistical differences were observed in RFA at T4 (90 days), between the SLActive® and LASER groups (p < 0.05) and between the SLActive® and LASER + HA groups (p < 0.05). At T6 and T7, statistical differences were found between the SLActive® group and all other implant surfaces (p < 0.01). The experimental surfaces analyzed showed encouraging positive outcomes compared to those of the SLActive® surface. Long-term follow-up should be performed to confirm these results.

Short Implants versus Longer Implants with Sinus Floor Elevation: A Systemic Review and Meta-Analysis of Randomized Controlled Trials with a Post-Loading Follow-Up Duration of 5 Years

This study compared the outcome of fixed prostheses supported by short implants (<8 mm) and longer implants (≥8 mm) with an elevated sinus floor after 5 years of follow-up. The literature searches were performed electronically and manually in PubMed, EMBASE, and Web of Science databases to identify relevant articles published from 1 January 2013 to 31 January 2020. We selected eligible studies using inclusion criteria and assessed their quality. From 1688 identified studies, five randomized controlled trials were included. Between the short implant group and the control group, the implant failure-related pooled risk ratio (RR) was 3.64 (p = 0.07). The RR for technical complications was 2.61 (p = 0.0002), favoring longer implants. Marginal peri-implant bone loss after 1 and 5 years of function showed statistically significant less bone loss at short implants (1 year: mean difference = 0.21 mm; p < 0.00001; 5 years: mean difference = 0.26 mm; p = 0.02). The implant failure and the biological failure of both groups were similar after 5 years of follow-up. Short implants could be an alternative to long implants with an elevated sinus floor for atrophic maxillae in aging populations. Studies with larger trials and longer periods of follow-up (10 years) remain essential.

Short vs. regular length implants to rehabilitate partially edentulous mandible: a 2-year prospective split-mouth clinical study

Many studies have evaluated short implants (SIs); however, it is still unclear whether SIs are reliable and can be used to simplify surgical and prosthetic protocols with successful clinical outcomes. The aim of this non-random, conveniently sampled, prospective, split-mouth study was to compare the clinical outcomes when short (SI) (≤8 mm) or regular-length implants (RIs) (>10 mm) were used in the posterior mandible two years after the delivery of splinted reconstructions. Each participant (N=10) received four implants in the posterior mandible; two SIs were placed on one side, and two RIs were placed contra-laterally. Implants were restored with splinted, screw-retained, porcelain-fused-to-metal reconstructions. Survival and success rates, peri-implant marginal bone level (MBL), and soft tissue parameters were evaluated. No participant drop-outs were recorded. Both types of implants showed 100% success and survival rates. From prosthetic delivery to 24 months post-loading, bone remineralization of +0.40 mm for the SIs and +0.36 mm for the RIs was observed without statistically significant differences in MBL between the implant types (p=0.993). SIs showed significantly higher (p=0.001) clinical attachment level (CAL) and probing depth (PD) values. Chipping occurred in one situation in the RI group resulting in a 97.5% prosthetic success rate, which was 100% for the SIs. After 2 years, SIs with splinted reconstructions showed comparable clinical outcomes to those of RIs. Further long-term controlled clinical studies with balanced experimental designs evaluating random and larger populations are required to corroborate these findings.

Short Dental Implants (≤8.5 mm) versus Standard Dental Implants (≥10 mm): A One-Year Post-Loading Prospective Observational Study

Background: Recent data have shown that short dental implants can be the preferred treatment in most of cases of posterior atrophic alveolar ridges, offering higher survival and lower complication rates than long implants. The survival rates, stability, and marginal bone level changes were compared between short implants (7 and 8.5 mm) and standard-length implants (≥10 mm). Methods: Prospective observational study in which adult patients requiring ≥1 osseointegrated implants to replace missing teeth were recruited consecutively. A clinical examination was performed on the day the definitive prosthesis was placed and after 6 and 12 months. Implant stability quotient (ISQ), marginal bone level (MBL) changes, and the correlation between these parameters and the characteristics of the implants were evaluated. Results: A total of 99 implants were inserted (47 short, 52 standard) in 74 patients. The 12-month survival rate was 100%. ISQ values showed a similar pattern for both types of implants. No correlation was found between ISQ changes after one year and MBL values, nor between the latter and the characteristics of the implants. Conclusions: With clinical treatment criteria, shorter implants (7 and 8.5 mm in length) can be just as useful as standard-length implants in atrophic alveolar ridges, demonstrating similar rates of survival, stability, and crestal bone loss.

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

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

Are There Alternatives to Invasive Site Development for Dental Implants? Part I

Edentulous sites are often characterized by inadequate bone volume for dental implant therapy. Bone augmentation procedures for site development involve longer healing period and are often invasive, costly, and associated with postoperative morbidity. This article discusses alternatives to invasive bone grafting procedures that are often used to develop implant sites. Owing to the broad nature of this topic, it is presented in two articles. In part I, the use of short and narrow-diameter implants are discussed. Part II reviews the use of tilted as well as fewer implants to support a prosthesis.

Short implants (5-8 mm) vs. long implants in augmented bone and their impact on peri-implant bone in maxilla and/or mandible: Systematic review

OBJECTIVE

The purpose of this systematic literature review is to determine the impact of implant length on marginal bone loss in atrophied arches.

MATERIAL AND METHODS

The systematic search of the literature was carried out using electronic databases PubMed, EbscoHost, Cochrane, as well as a manual search of randomized controlled trials in humans, with a follow-up period of at least 12 months, published between 2005 and 2016, comparing the short implants on the one hand, and the long implants placed in atrophic bone crests having undergone bone augmentation on the other hand. This systematic review followed the guidelines of PRISMA Statement (Preferred Reporting Items for Systematic Reviews and Meta-Analyzes). The results of the clinical trials were described according to the PICO criteria. The qualitative analysis was conducted by Jadad scale and the Cochrane Collaboration's tool for assessing risk of bias.

RESULTS

Thirteen randomized controlled trials (RCTs) were included in our systematic review. Gradual marginal bone loss (intra-group comparison) was significant regardless of the arcade. The difference in bone loss between short and long implants (inter-group comparison) was not significant in the first year, but became significant at the end of the fifth year regardless of the arcade.

CONCLUSION

Despite the satisfactory results in relation to short implants, it is appropriate to extend the duration of RCTs up to 10 years in order to support the data collected in our systematic review.

Short Implants Versus Standard Implants: Midterm Outcomes of a Clinical Study

INTRODUCTION

The aim of this study was to evaluate the midterm survival rate, marginal bone resorption (MBR), and stability of short implants and to compare the results with standard length implants.

MATERIALS AND METHODS

A total of 38 patients were included. In total, 147 implants (Nucleoss Implants, Izmir, Turkey) were placed (86 short implants and 61 standard implants). Cement-retained metal-ceramic prostheses were fabricated. MBR was evaluated on periapical radiographs taken at implant placement, at the time of crown insertion and annually thereafter. The stability of the implants was evaluated by resonance frequency analysis.

RESULTS

The 3- and 5-year cumulative survival rates for standard implants was 98.4% and for short implants was 96.5% (P = 0.644). The MBR of the short implants was significantly lower than that of the standard implants after 1, 2, and 3 years of loading (P < 0.05). No significant differences were found between 2 groups after 6 and 12 months of loading in terms of implant stability (implant stability quotient values) (P > 0.05).

CONCLUSION

Within the limits of this study, it is concluded that short implants achieved similar results as standard implants after 3 to 5 years of loading.

Short vs. Standard Laser-Microgrooved Implants Supporting Single and Splinted Crowns: A Prospective Study with 3 Years Follow-Up

PURPOSE

The aim of this study was to compare survival rates, marginal bone loss (MBL), and peri-implant soft tissue parameters between short and standard laser-microgrooved implants supporting single or splinted crowns 3 years after loading.

MATERIALS AND METHODS

30 subjects received 1 short ( ≤ 7 mm ) and 1 standard length ( ≥ 9 mm ) laser-microgrooved implant in adjacent sites of the premolar and molar regions of the mandible or maxilla. Peri-implant soft tissue parameters and intraoral radiographs were recorded at the delivery of definitive crowns (baseline) and 3 years later. Cumulative survival rate (CSR) and marginal bone loss (MBL) in relation to crown/implant (C/I) ratio, implant length, location, type of antagonist, and type of prosthetic design (single or splinted), were evaluated.

RESULTS

CSR of short implants was 98%, compared to 100% for standard implants, without significant statistical difference. MBL was not significantly different over the observation period, with an average of 0.23 ± 0.6 mm and 0.27 ± 0.3 mm for short and standard implants, respectively. No statistical differences were found between short and standard implants regarding plaque (14.7% vs. 15.7%), number of sites BOP (8.3% vs. 5.9%), probing depth (1.13 ± 0.6 mm vs. 1.04 ± 0.8 mm), and mean mucosal recession (0.18 ± 0.3 mm vs. 0.22 ± 0.3 mm). Analyzing MBL in relation to the C/I ratio, implant length, location, type of antagonist, and type of prosthetic design, no statistically significant differences were found.

CONCLUSION

Regardless of C/I ratio, implant length, location, type of antagonist, and type of prosthetic design, short and standard laser-microgrooved implants had similar survival rates, MBL, and peri-implant soft tissue conditions over the observation period of 3 years.

Clinical comparison of short and conventional implants placed in the posterior region of the mandible. A pilot study

Abstract Objective To evaluate and correlate the values of radiographic bone density, peri-implant bone height and resonance frequency analysis (RFA) of short or conventional implants placed in the posterior region of the mandible after installing a prosthesis. Material and method Eleven patients were selected for this prospective parallel pilot study. The prostheses were supported by two types of implants: short implants (n = 18) (5.0 x 5.5 mm and 5.0 x 7.0 mm) and conventional implants (n = 23) (4.0 x10 mm and 4.0 x 11.5 mm). The implants were evaluated by RFA, by measuring the bone height, and peri-implant bone density. The implants were evaluated at the periods T0 (immediately after installation of the prosthesis), T1 (after 90 days), and T2 (after 180 days). Result There were no statistically significant differences between groups with respect to radiographic bone density (152.50 ± 15.39 vs. 157.60 ± 28.46, for conventional and short implants, respectively at T2), stability of the implants (Conventional implants: 66.76 ± 10.39 at T0, and 61.85 ± 8.38 at T2 vs. Short implants: 57.50 ± 12.17 at T0, and 61.53 ± 7.39 at T2) and peri-implant bone loss (0.03 mm vs.-0.17 mm, for conventional and short implants, respectively at T2). Additionally, a significant correlation between the evaluated parameters was not detected. Conclusion The short and conventional implants presented similar stability, bone level and density after the activation of occlusion loading.

Recent advances in dental implants

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

Relationship between implant stability on the abutment and platform level by means of resonance frequency analysis: A cross-sectional study

Resonance frequency analysis (RFA) has become the main tool used to assess the osseointegration of dental implants. The objective of this study was to verify the relationship between the ISQ values with different prosthetic abutments and with the implant platform. The hypothesis was that ISQ values changes according to the abutment height. Twelve patients were included, whose contribution to the study was 31 dental implants (external hexagon connection implants, 4.1x10 mm). The temporary implant-supported crown and prosthetic components were removed and the following smartpegs were inserted, one at a time: type 1, in the implant platform (G1); type A3, in the microunit component with 1mm transmucosal height (G2) and type A3, in the microunit component with 5mm transmucosal height (G3). In all the smartpegs, RFA measurements were taken on mesial, distal, buccal and lingual surfaces. All evaluations were performed by a single calibrated examiner (ICC = 0.989). Data were analyzed by Friedman and Spearman correlation tests and log-linear marginal regression (p<0.05). The mean age of participants was 52.83 (± 3.77) years. There was statistically significant difference (p<0.001) among the mean ISQ of G1 (88.27 ±5.70); G2 (72.75 ±4.73) and G3 (66.33 ±3.67). There was statistically significant negative correlation between the ISQ and the measurement distance (rs:-0.852; p<0.001; R2:0.553). Measurement distance was significantly associated (p<0.001) with ISQ value in the log-linear regression. The abutment height has a significant impact on resonance frequency analysis measurements. The higher the transmucosal abutment height, the lower the implant stability quotient value. Clinically, the ISQ measured on the abutment cannot be compared with values measured on the implant platform.

Short dental implants in the posterior maxilla: a review of the literature

The purpose of this study was to perform a literature review of short implants in the posterior maxilla and to assess the influence of different factors on implant success rate. A comprehensive search was conducted to retrieve articles published from 2004 to 2015 using short dental implants with lengths less than 10 mm in the posterior maxilla with at least one year of follow-up. Twenty-four of 253 papers were selected, reviewed, and produced the following results. (1) The initial survival rate of short implants in the posterior maxilla was not related to implant width, surface, or design; however, the cumulative success rate of rough-surface short implants was higher than that of machined-surface implants especially in performance of edentulous dental implants of length <7 mm. (2) While bone augmentation can be used for rehabilitation of the atrophic posterior maxilla, short dental implants may be an alternative approach with fewer biological complications. (3) The increased crown-to-implant (C/I) ratio and occlusal table (OT) values in short dental implants with favorable occlusal loading do not seem to cause peri-implant bone loss. Higher C/I ratio does not produce any negative influence on implant success. (4) Some approaches that decrease the stress in posterior short implants use an implant designed to increase bone-implant contact surface area, providing the patient with a mutually protected or canine guidance occlusion and splinting implants together with no cantilever load. The survival rate of short implants in the posterior edentulous maxilla is high, and applying short implants under strict clinical protocols seems to be a safe and predictable technique.

Vertical Alveolar Distraction Osteogenesis of the Atrophic Posterior Mandible Before Dental Implant Insertion

PURPOSE

Augmentation of deficient mandibular posterior alveolar ridges poses a great challenge because of extensive bone deficiency and the presence of the inferior alveolar nerve. This study sets its focus on vertical alveolar distraction osteogenesis (ADO) at the posterior mandible before dental implant placement.

MATERIALS AND METHODS

The study included 21 sites in 18 patients with severe mandibular posterior alveolar ridge deficiency. A trapezoidal osteotomy was performed, and an extraosseous alveolar distraction device was fixed and activated after a 4-day latency period at a rate of 0.5 mm/day. After a 4-month retention period, the distraction device was removed and titanium dental implants were placed.

RESULTS

A mean vertical augmentation of 14.47 mm was gained. The newly formed bone was shown using panoramic radiography and computed tomography. We placed 56 dental implants, and during a minimum follow-up period of 36 months, 2 implants were lost, resulting in a success rate of 96.42%.

CONCLUSIONS

ADO offers marked vertical ridge augmentation with simultaneous soft tissue expansion and stable results. ADO diminishes the need for autogenous bone graft, thus sparing donor-site morbidity. ADO of the deficient posterior mandibular alveolar ridge is useful in moderate to severe bony deficiencies and allows for adequate bone formation, which allows implant insertion.

Implant stability after sinus floor augmentation with deproteinized bovine bone mineral particles of different sizes: a prospective, randomized and controlled split-mouth clinical trial

The aim of this study was to compare implant stability after maxillary sinus floor augmentation using small- or large-sized particles of Bio-Oss. Ten partially edentulous patients requiring bilateral maxillary sinus floor augmentation were enrolled. The subjects were assigned randomly to one of two experimental groups: maxillary sinus was filled with 0.25-1mm particle size (small particles) and the contralateral side was filled with 1-2mm particle size (large particles). After 8 months, a total of 25 implants were placed in the two maxillary sinuses. Primary implant stability was measured immediately after implant placement (T0) using a torque controller and resonance frequency analysis (RFA). Six months after implant placement (T1), the implant stability was measured again. There were no postoperative complications in either particle size group, and the success rate for implant survival was 100%. All implants showed good primary stability as evidenced by high torque for the implant insertion in both groups. RFA revealed high ISQ values for all implants installed in both groups at T0 and T1. These results indicate that the size of the Bio-Oss particles (small and large) did not influence implant stability in the maxillary sinus. Indeed, small and large particles of Bio-Oss presented optimal properties, supporting their possible use as osteoconductive grafts.

In Vitro Evaluation of the Primary Stability of Short and Conventional Implants

The objective of this study was to evaluate the primary stability of short and conventional dental implants with different platform types at different site densities in vitro. One hundred twenty implants were placed in polyurethane blocks that simulate different bone densities (bone types I and IV). The implants were divided into 10 groups, with 12 implants each according to the type of prosthetic connections (external hexagon, EH; morse taper, MT) and size of the implants (conventional: 4 × 10 mm; short: 5 × 5, 5.5 × 5, 5 × 6, and 5.5 × 6 mm). Insertion torque and resonance frequency analyses were performed to evaluate the primary stability. The Kruskal-Wallis test complemented by Dunn's test and the Mann-Whitney test were used for statistical analysis. These tests were applied at the confidence level of 95% (P < .05). The implants installed in blocks with density type IV exhibited reduced insertion torque compared with implants placed in blocks with density type I. Short implants with EH exhibited increased insertion torque compared with short implants with MT in blocks with bone density type I. In general, implants installed in blocks with density type I exhibited greater primary stability. The short implants with EH with a 5.5-mm diameter and the short implants with MT with a 5-mm diameter exhibited reduced primary stability. No differences between short and conventional implants were noted. Short implants have primary stability and insertion torque at least equivalent to conventional implants irrespective of the platform type and density of the site.

Short dental implants versus standard dental implants placed in the posterior jaws: A systematic review and meta-analysis

OBJECTIVE

The purpose of the present systematic review and meta-analysis was to compare short implants (equal or less than 8mm) versus standard implants (larger than 8mm) placed in posterior regions of maxilla and mandible, evaluating survival rates of implants, marginal bone loss, complications and prosthesis failures.

DATA

This review has been registered at PROSPERO under the number CRD42015016588. Main search terms were used in combination: dental implant, short implant, short dental implants, short dental implants posterior, short dental implants maxilla, and short dental implants mandible.

SOURCE

An electronic search for data published up until September/2015 was undertaken using the PubMed/Medline, Embase and The Cochrane Library databases.

STUDY SELECTION

Eligibility criteria included clinical human studies, randomized controlled trials and/or prospective studies, which evaluated short implants in comparison to standard implants in the same study.

CONCLUSION

The search identified 1460 references, after inclusion criteria 13 studies were assessed for eligibility. A total of 1269 patients, who had received a total of 2631 dental implants. The results showed that there was no significant difference of implants survival (P=.24; RR:1.35; CI: 0.82-2.22), marginal bone loss (P=.06; MD: -0.20; CI: -0.41 to 0.00), complications (P=.08; RR:0.54; CI: 0.27-1.09) and prosthesis failures (P=.92; RR:0.96; CI: 0.44-2.09). Short implants are considered a predictable treatment for posterior jaws. However, short implants with length less than 8 mm (4-7 mm) should be used with caution because they present greater risks to failures compared to standard implants.

CLINICAL SIGNIFICANCE

Short implants are frequently placed in the posterior area in order to avoid complementary surgical procedures. However, clinicians need to be aware that short implants with length less than 8mm present greater risk of failures.