Standard-length Implants Research Articles

Comparison of 6‐mm and 11‐mm dental implants in the posterior region supporting fixed dental prostheses: 5‐year results of an open multicenter randomized controlled trial

ObjectiveThe aim of this multicenter, randomized controlled trial was to compare the clinical and radiographic outcomes of 6‐mm or 11‐mm implants, placed in the posterior maxilla and mandible, during a 5‐year follow‐up period.Materials and methodsNinety‐five patients with adequate bone height for 11‐mm implants, were randomly allocated to a 6‐mm group (test group with short implants) or an 11‐mm group (control group with standard‐length implants). Two or three implants of the same length were placed in each patient and after 6 weeks loaded with a splinted provisional restoration. This was followed by definitive splinted restoration 6 months after implant placement. Clinical and radiographic parameters, including the occurrence of complications were recorded.ResultsA total of 49 patients were enrolled to receive 6‐mm implants (n = 108) and 46 patients to receive 11‐mm implants (n = 101). Three implants (two of 6 mm and one of 11 mm in length) were lost before loading and one 6‐mm implant after 15 months of function, and one 11‐mm implant was lost during the first year of function. The 5‐year survival rates were 96.0% and 98.9% in the 6‐mm and 11‐mm group, respectively. The mean marginal bone level changes 5 years post‐loading were 0.01 ± 0.45 mm (bone gain) in the 6‐mm group and −0.12 ± 0.93 mm (bone loss) in the 11‐mm group (p = .7670). Clinical parameters, including plaque, bleeding on probing and pocket probing depth were not significantly different between the groups, and also technical complications were low.ConclusionThe clinical and radiographic outcomes of 6‐mm short and 11‐mm standard‐length implants were not different during a 5‐year evaluation period.

Mandibular implant-supported fixed complete dental prostheses on implants with ultrashort and standard length: A pilot treatment

Edentulous patients may be restored with complete-arch implant-supported fixed complete dental prostheses (IFCDPs) on angled distal implants or on parallel implants distributed equally across the mandible to increase the area of support. A treatment is presented to introduce the clinical concept of providing edentulous patients with an implant-supported fixed complete dental prosthesison parallel tissue-level implants in the mandible with standard length implants interforaminally and ultrashort implants distally. A structured prosthetic approach was used for the tooth arrangement with a modified workflow as per the Biofunctional Prosthetic System adapted for static computer-aided implant surgery (s-CAIS) and computer-aided design and computer-aided manufacturing (CAD-CAM) of the screw-retained implant-supported fixed complete dental prosthesis. The concept offered advantages in challenging anatomic, surgical, and prosthetic conditions; providing distal nonangled abutments and implant platforms, which were straightforward to clean. If necessary, the prosthesis could have been easily converted into a removable overdenture using the existing digital prosthetic arrangement. Should implant removal be required, the extrashort implants can be removed with minimal surgical risk or morbidity.

Immediate Loading of Fixed Partial Dental Prostheses on Extra-Short and Short Implants in Patients with Severe Atrophy of the Posterior Maxilla or Mandible: An Up-to-4-year Clinical Study.

The goal of this study was to evaluate the cumulative survival rate and marginal bone loss (MBL) of extra-short (5- and 6-mm-long) and short (6.5-mm-long) implants inserted into severely atrophic, partially edentulous posterior maxillae and mandibles that were immediately restored with provisional fixed dental prostheses. Between October 2013 and December 2017, partially edentulous patients with severe vertical bone atrophy in the posterior area in need of replacement of premolars and/or molars with fixed prostheses were enrolled in the study. Analysis of cumulative survival rate and MBL was determined with respect to implant length at the longest, biannual follow-up period (38 ± 10 months; range: 25 to 48 months). Fifty-five patients were included in the study. A total of 62 extra-short (5 and 6 mm), 15 short (6.5 mm), and 69 standard-length (≥ 10 mm) implants were immediately placed and loaded. Cumulative survival rates were similar for all implants (99.3%). One mandibular extra-short implant failed and was removed but was replaced 2 months later with another implant of the same length and diameter and successfully reloaded. Implant length did not impart any significant differences in MBL, though the presence or absence of platform switching was influential. The cumulative survival rate and MBL reported in this study encourage the use of short and extra-short implants to immediately restore with fixed prostheses partially edentulous patients with severe vertical bone atrophy in posterior areas. Thus, it could be an alternative treatment to vertical bone augmentation.

EVALUATION OF STRAIN DEVELOPED AROUND SHORT DENTAL IMPLANTS USING TWO DIFFERENT RESTORATIVE MATERIALS (IN VITROSTUDY)

Introduction: The use of short implants has been introduced as an alternative treatment for posterior regions, however, it leads to serious prosthetic complications. Using CAD/CAM, materials like zirconia and Bio-HPP can be used to fabricate implant supported restorations. Objectives: This study aimed to evaluate and compare the strains developed around short and standard implant length using two different crown materials. Materials and methods: Polyurethane blocks (n=20) were used as alternative materials for human cancellous bone. Blocks were divided into two groups, group A received ten standard length implants 12 mm, and group B received ten short implants 7 mm. Each group was equally subdivided into two subgroups, according to crown material (BioHPP and zirconia). Universal testing machine was used to apply a load of 100 N axially and obliquely at 45° on the restorations. Microstrains were measured using strain meter. Results:The difference in microstrain values between BioHPP and zirconia was statistically insignificant for both group A and group B. Comparing between group A and group B having the same restorative materials, it was found that, the difference was statistically significant for zirconia in axial loading only. A significant difference was observed between oblique and axial loads in standard implant length for both BioHPP and zirconia restorations, and for zirconia in short implants as well (p value=0.043), while the difference was insignificant for BioHPP in short implants. Conclusions: Short implants are comparable treatment modality to standard implant lengths for single tooth restoration. Oblique forces produce more stresses than vertical forces. According to the average of loads, there is no significant difference between BioHPP and zirconia for both short and standard implant length. However, it is advisable not to use zirconia restorations with short implants.

Short vs. Standard Length Cone Morse Connection Implants: An In Vitro Pilot Study in Low Density Polyurethane Foam

The aim of the investigation was to evaluate the insertion torque, pull-out torque and implant stability quotient (ISQ) of short implants (SI) and standard length implants (ST) inserted into linearly elastic and constitutive isotropic symmetry polyurethane foam blocks. Short dental titanium implants with a Cone Morse connection and a conical shape (test implants: Test Implant A—diameter 5.5 mm and length 6 mm) (Test Implant B—diameter 5.5 mm and length 5 mm) were used for the present in vitro investigation. ST implants (4 mm diameter and 10 mm length), with a Cone Morse connection and a conical shape, were used as Control Implant A and as Control Implants B. These two latter implants had a different macro design. A total of 20 implants (5 Test A, 5 Test B, 5 Control A and 5 Control B) were used for the present research. The results were similar when comparing the Test A and Test B implants. The test implants had very good stability in polyurethane 14.88–29.76 kgm3 density blocks. The insertion torque values were very high for both types of test implant (25–32 Ncm on 14.88 kgm blocks, and up to 45 Ncm in 29.76 kgm3 blocks). The pull-out test values were very similar to the insertion torque values. The ISQ values were significantly high with 75–80 in 14.88 kgm3 blocks, and 78–83 in 29.76 kgm3 blocks. No differences were found in the values of the Control A and Control B implants. In both these implants, the insertion torque was quite low in the 14.88 kgm3 blocks (16–28 Ncm). Better results were found in the 29.76 kgm3 blocks. The pull-out values for these control implants were slightly lower than the insertion torque values. High ISQ values were found in both control implants (57–80). When comparing SI and ST implants, the SI had a similar if not better performance in low quality polyurethane foam blocks (14.88–29.76 kgm), corresponding to D3 and D4 bone.

7-mm-long dental implants: retrospective clinical outcomes in medically compromised patients.

ObjectivesDental implants shorter than 8 mm, called short dental implants (SDIs), have been considered to have a lower success rate than standard length implants. But recent studies have shown that SDIs have a comparable success rate, and implant diameter was more important for implant survival than implant length. Also, SDIs have many advantages, such as no need for sinus lifting or vertical bone grafting, which may limit use in medically compromised patients.Materials and MethodsIn this study, 33 patients with 47 implants 7-mm long were examined over the last four years. All patients had special medical history and were categorized into 3 groups: systemic disorders, such as diabetes mellitus (controlled or uncontrolled), mental disability, and uncontrolled hypertension; oral cancer ablation with reconstruction, with or without radiotherapy; diverse osteomyelitis, such as osteoradionecrosis and bisphosphonate-related osteonecrosis of the jaw. Most of these patients have insufficient residual bone quality due to mandible atrophy or sinus pneumatization.ResultsThe implant diameters were 4.0 (n=38), 4.5 (n=8), and 5.0 mm (n=1). Among the 47 implants placed, 2 implants failed before the last follow-up. The survival rate of 7-mm SDIs was 95.74% from stage I surgery to the last follow-up. Survival rates did not differ according to implant diameter. The mean marginal bone loss (MBL) at 3 months, 1 and 2 years was significantly higher than at implant installation, and the MBL at 1 year was also significantly higher than at 3 months. MBL at 1 and 2 years did not differ significantly.ConclusionWithin the limitations of the present study, the results indicate that SDIs provide a reliable treatment, especially for medically compromised patients, to avoid sinus lifting or vertical bone grafting. Further, long-term follow-up is needed.

Influence of Implant Length and Associated Parameters Upon Biomechanical Forces in Finite Element Analyses: A Systematic Review.

The aim of this systematic review is to provide an overview of finite element analyses comparing standard and short dental implants concerning biomechanical properties and to detect the most relevant parameters affecting periimplant stress concentrations. After screening the literature and assessment of studies, 36 studies were included in this review. Eighty-three percent of the studies state that short dental implants have to bear higher stress concentrations compared with standard length implants. At the same time, 44% of articles note that implant diameter can be considered a more effective design parameter than implant length to reduce stress concentrations and to avoid an overload of periimplant bone. Regardless of implant dimension, in all studies, the highest stress concentrations are found in the cortical section around the upper part of the implant. Unaffected of bone quality, implant diameter is found to play a key role to minimize periimplant stress concentrations. Concerning stress reduction implant length gains increasing relevance with decreasing bone density. Furthermore, splinting of short implants constitute an appropriate tool to avoid crestal overloading.

Long-term survival analysis of standard-length and short implants with multifunctional abutments.

Spherical shape and connecting bypass screw of the OT Equator abutment (Rhein83, Italy) provides several retentive possibilities, even in non-parallel implants. This study assessed the long-term survival of standard-length and short implants receiving this multifunctional abutment. Partially, edentulous patients (44 males and 64 females) (mean age 58.2±10.5years) rehabilitated with a fixed implant-supported prosthesis where the OT Equator abutments (Rhein83) were applied. Follow-up evaluations were performed up to 5years following prosthesis delivery. Kaplan-Meier survival analysis and Cox regression analysis were used to determine whether the distribution of time to failure differed based on implant characteristics (length and region), adjusting for sex (α=0.05). In total, 216 implants (5×8mm, n=126; 5×6mm, n=90) (Betwice, Mech & Human, Italy) were installed. The average follow-up period was 25.3months (±19.3months). Eight failures occurred, with most observed before loading (n=6). Cumulative survival rates (CSR) at implant and abutment levels were 94.3% and 97.1%, respectively. Regarding implant length, CSRs were 97.8% and 90.6% for short and standard-length implants, respectively, with no difference between subgroups (logrank: χ2 =1.34, df=1, P=0.25). No significant difference was also found between implants of maxilla (CSR=92.2%) and mandible (CSR=95.5%; logrank: χ2 =0.08, df=1, P=0.78). The OT Equator abutment (Rhein83) showed a stable clinical performance, with continuous and predictable survival.

Implants in the Posterior Maxilla: Open Sinus Lift Versus Conventional Implant Placement. A Systematic Review.

To compare implant survival, marginal bone loss, peri-implant clinical parameters, and complications in dental implants placed in the posterior maxilla in native bone or after grafting using the open sinus lift technique. A search was made of two electronic databases (MEDLINE via PubMed and the Cochrane Oral Health Group Trials Register [CENTRAL]), complemented by a manual search. The study included randomized clinical trials, non-randomized clinical trials, and observational studies such as cohort studies and case-control studies conducted on a prospective or retrospective basis and comparing the placement of standard length implants (≥ 10 mm) in native bone or after grafting using the sinus lift procedure. Risk of bias was evaluated with the Cochrane risk of bias assessment tool and the methodological index for non-randomized studies (MINORS). The search yielded 90 studies, of which 23 were included. Two studies were evaluated with the Cochrane risk of bias assessment tool, with neither being identified as presenting low risk of bias. Twenty-one studies were evaluated by the MINORS, yielding a mean score of 15.66 points out of 24. The implant survival rate in the control group was 90% to 100% versus 75.3% to 100% in the test group over a follow-up period of 6 to 120 months. Most studies revealed no statistically significant differences. In most of the publications, marginal bone loss was greater in the test group than in the control group, though without reaching statistical significance. Similar results were obtained in both groups with regard to the peri-implant clinical parameters. There were more surgical complications in the test group than in the control group-such complications being inherent to the sinus lift procedure. Implant placement after sinus lift affords results in terms of implant survival, marginal bone loss, and peri-implant clinical parameters similar to those obtained with conventional implant placement in native bone. However, there is a greater incidence of surgical complications associated with the sinus lift procedure.

Short dental implant as alternative to long implant with bone augmentation of the atrophic posterior ridge: a systematic review and meta-analysis of RCTs.

To evaluate if short implants without augmentation can be considered a successful alternative treatment modality in the rehabilitation of posterior atrophic ridges when compared to standard-length implants with augmentation. Electronic searches were performed in the PubMed and Cochrane Central Register of Controlled Trials (CENTRAL) databases. Randomized controlled trials (RCTs) that compared short implants and standard implants with augmentation were the only articles included. Titles and abstracts were screened, data were extracted, and articles were assessed for risk of bias. Meta-analyses were performed for 13 of the included RCTs that had similar outcome measures. Of the total 17 relevant studies identified, 13 RCTs fulfilled the inclusion criteria. The meta-analysis showed no significant differences regarding the implant failure rate at 1 year (I2 = 67%, P = .13; risk difference [RD]: -0.05, 95% confidence interval [CI]: -0.11, 0.01), at 3 years (I2 = 58%, P = .17; RD: -0.04, 95% CI: -0.01, 0.02), and at 5 to 10 years (I2 = 0%, P = .47; RD: -0.05, 95% CI: -0.19, 0.09). However, the meta-analyses of 10 trials regarding the postoperative complications of short- and standard-length dental implants showed a significantly higher rate of postoperative complications in the standard-length dental implant group at 1 year (I2 = 93%, P = .02; RD: -0.21, 95% CI: -0.39, -0.04). Short dental implants seem to be an effective alternative treatment for the atrophic posterior ridge. The pooled data revealed that short dental implants have statistically less marginal bone loss and fewer postoperative complications when compared to standard-length dental implants with augmentation. However, there are no statistically significant differences in regard to implant failure.

Randomized controlled multicentre study comparing short dental implants (6 mm) versus longer dental implants (11–15 mm) in combination with sinus floor elevation procedures: 5‐Year data

To compare the implant survival rate between short dental implants and standard length implants placed in combination with bone grafting at 5years of loading. This multicentre study enrolled 101 patients (137 implants) with a posterior maxillary bone height of 5-7mm. Patients randomly received either short implants (6mm; GS) or long implants (11-15mm) with sinus grafting (GG). Six months later, implants were loaded with single crowns and patients re-examined at 1, 3 and 5years of loading. Outcomes included: implant survival, marginal bone levels (MBLs), biological and technical parameters and patient-reported outcome measures (OHIP-49=Oral Health Impact Profile). Statistical analysis was performed using a non-parametric approach. At 5years, 90 patients (124 implants; GS: 60; GG: 64) were re-examined (drop-out rate 10%). Patient-level implant survival rates were 98.5% (GS; 1 implant failure) and 100% (GG; p=0.49). Mean MBLs were 0.54mm±0.87 (GS) and 0.46mm±1.00 (GG; p=0.34). Biological and technical parameters were not significantly different (p>0.05). Median overall OHIP-49 scores improved significantly up to 5years in both groups (GS: p=0.03; GG: p=0.00; intergroup comparison p=0.11). Both treatment modalities were suitable for implant therapy in the atrophied posterior maxilla revealing no differences in terms of survival rates, marginal bone levels (changes), patient-reported outcomes and technical/biological complications.

Marginal bone level and survival of short and standard-length implants after 3 years: An Open Multi-Center Randomized Controlled Clinical Trial.

The present multi-center randomized controlled clinical trial sought to compare the marginal bone level (MBL) changes and survival of 6- and 11-mm implants. Ninety-five patients receiving a total of 209 dental implants were enrolled. Subjects were randomly allocated to two cohorts: test (4.0×6mm; N=108) or control (4.0×11mm; N=101) implant groups. To be randomized, all edentulous sites were anatomically qualified to receive 11mm implant. Two to three implants were placed in maxillary or mandibular posterior regions and loaded with splinted provisional restoration after 6weeks and definitive restoration 6months thereafter. Test and control implants were followed by clinical and radiographic examinations on an annual basis up to 3years. Radiographic assessment of MBL 3years after loading revealed the bone to be located at 0.27mm (±0.40) and 0.44mm (±0.74) apical to the implant platform in the test and control groups, respectively. During the 3years of follow-up since loading, 0.04mm (±0.43) MBL gain and 0.02mm (±0.76) of MBL loss were observed in the 6-mm (test) and 11-mm (control) groups, respectively. The MBL's for test and control were significantly different (p=0.000) in favor of short implants. The cumulative survival rates from placement after 3years were 96% and 99% for the 6- and 11-mm implants, respectively, with no statistical significance. Reconstruction of partially edentulous posterior maxilla or mandible with 6- or 11-mm implants led to stable marginal bone level and high implant survival rate after 3years.

Prosthetic Rehabilitation of the Partially Edentulous Atrophic Posterior Mandible with Short Implants (≤ 8 mm) Compared with the Sandwich Osteotomy and Delayed Placement of Standard Length Implants (> 8 mm): a Systematic Review.

ABSTRACTObjectivesTest the hypothesis of no difference in prosthetic rehabilitation of the partially edentulous atrophic posterior mandible with short implants (≤ 8 mm) compared with the sandwich osteotomy and delayed placement of standard lengths implants (> 8 mm).Material and MethodsA MEDLINE (PubMed), Embase and Cochrane library search in combination with a hand-search was conducted by including studies published in English. No year of publication restriction was applied.ResultsSix randomized controlled trials characterized by low or moderate risk of bias fulfilled the inclusion criteria. There were no statistically significant differences (P > 0.05) in the survival rate of suprastructures and implants between the two treatment modalities after one year. Sandwich osteotomy and delayed implant placement demonstrated statistically significant higher long-term peri-implant marginal bone loss as well as biological and technical complications compared with short implants (P < 0.0001). Moreover, patients significantly favoured prosthetic rehabilitation with short implants (P < 0.0001).ConclusionsShort implants and the sandwich osteotomy with delayed placement of standard length implants appear to result in predictable outcomes in terms of high survival rate of suprastructures and implants after prosthetic rehabilitation of the partially edentulous atrophic posterior mandible. However, further long-term randomized controlled trials assessing donor site morbidity, an economic perspective, professional and patient-related outcome measures with the two treatment modalities are needed before definite conclusions can be provided about the beneficial use of short implants for prosthetic rehabilitation of the partially edentulous atrophic posterior mandible compared with the sandwich osteotomy and delayed placement of standard length implants.

Short dental implants as compared to maxillary sinus augmentation procedure for the rehabilitation of edentulous posterior maxilla: Three-year results of a randomized clinical study.

Several treatment options exist for the implant-supported rehabilitation of edentulous posterior maxilla. To compare maxillary sinus floor augmentation associated to standard length implants, with direct placement of implants of reduced length in the available residual bone. Patients with edentulous posterior maxilla and a residual height of 4-7 mm were randomly allocated to the test (short implants [SIs], 6.5 to 8.5mm long) or the control (sinus augmentation [SA] and implants ≥10mm long) group. Anorganic bovine bone was the grafting material for the control group. In both groups pure platelet-rich plasma was used to bioactivate implant surface prior to insertion. Implant and prosthesis survival, clinical variables, radiographic bone level change, quality of life, and patient satisfaction were assessed. Twenty-five patients were treated in the control group (58 standard length implants) and 27 in the test group (42 SIs). After 3 years of follow-up no implant failure and biological or mechanical complications were recorded. Marginal bone loss, soft tissue, and oral hygiene parameters were similar in the 2 groups at both 1 and 3 years' follow-up. Postoperative pain, swelling and other symptoms and daily activities were better in the SIs group than in the SA group, while patients' satisfaction after 1 year was similar. In spite of comparable medium-term clinical and radiographic outcomes, when the residual ridge height is sufficient for a safe placement, SIs may be preferred due to simplified protocol, less invasiveness, shorter treatment time, and reduced postoperative discomfort as compared to SA.

Short implants versus bone grafting and standard-length implants placement: a systematic review.

The aim of this study was to conduct a systematic review to compare the survival rates between short implants (length<10mm) versus standard-length implants (≥10mm) inserted in grafted bone. As secondary outcomes, marginal bone loss and survival rates of the implant supported prostheses were also analysed. Randomised controlled trials (RCT) that compared both techniques were searched on three electronic databases till June 2016, a manual search was performed on the bibliography of the collected articles, and the authors were contacted for additional references. The estimates of the interventions were expressed in relative risk (RR), mean implant survival rates and mean differences in marginal bone. Eight RCTs were included in this study. From a total of 458 short implants, 15 failed (mean survival rates=96.7%), While from 488 regular implants, 13 failed (mean survival rates=97.3%). The technique did not significantly affect: the implant failure rate (P>0.05), with RR of 1.34 (95% CI 0.67-2.87), the mean differences of marginal bone loss (P=0.18; MD -0.04mm [-0.10; 0.02] 95% CI), at loading or prosthesis failures rates (RR:0.98; 95% CI 0.40-2.41). The mean differences of marginal bone at 1year follow-up (post loading) presented significant marginal changes in the short implant group (P=0.002; MD -0.10mm [-0.16; -0.03] 95% CI) although a significant high heterogeneity was found between groups. This systematic review suggests no difference between both techniques in the treatment of atrophic arches. However, more long-term RCTs are needed to evaluate the predictability at the long run. The use of short implants might be considered an alternative treatment, since it usually requires fewer surgical phases and tends to be a more affordable option.

Short implants (6 mm) vs. vertical bone augmentation and standard-length implants (≥9 mm) in atrophic posterior mandibles: a 5-year retrospective study

This retrospective study compared the 5-year clinical and radiographic outcomes of short implants (6 mm) (short group), and standard-length implants (≥9mm) placed after a vertical augmentation with autologous bone blocks (augmentation group), supporting partial fixed prostheses in the posterior mandible. Forty-five partially edentulous patients were enrolled in the study and evaluated after 5 years: 22 (51 implants) in the augmentation group and 23 (46 implants) in the short group. Eight surgical complications occurred in the augmentation group versus none in the short group (P=0.003). One short implant failed before loading and one standard-length implant failed after 4 years because of peri-implantitis (P=1.0). Eight biological and two prosthetic complications occurred in the augmentation group vs. three biological and three prosthetic complications in the short group (P=0.09 and P=1.0, respectively). A mean marginal bone loss of 1.61±1.12mm in the augmentation group and 0.68±0.68mm in the short group was found (P=0.002). Within the limitations of this study, both techniques resulted in successful clinical results after 5 years, but short implants exhibited less surgical complications and marginal bone loss than standard-length implants placed in augmented bone.

Combination of short implants and a unilateral distal-extension implant-retained partial denture in case of severely reduced ridge height mandibular posterior region: 12-year follow-up

This case report describes the treatment of a woman who lost mandibular posterior teeth. The bilateral alveolar ridges showed severe tissue defects. She complained of the discomfort of a partial denture connected by a lingual bar and wished for fixed prostheses. However, the height of the alveolar bone was insufficient to place standard-length implants. In addition, she rejected bone augmentation and the usage of biomaterials. Therefore, short implants were placed in both sides of atrophic alveolar ridges without tissue augmentation. Conventional crowns were placed on the right side on three short implants, and a unilateral distal-extension partial implantretained partial denture (IRPD) using magnetic attachment was placed on the left side using the two available short implants. The patient was satisfied with the outcome of this treatment for 12 years even though a clasp was added to the removable partial denture at 11 years due to the wear of the magnet keepers. The combination of short implants and an IRPD using magnetic attachment is effective for patients with a severely atrophic posterior mandibular from the aspect of minimal intervention.

Treatment concepts for the posterior maxilla and mandible: short implants versus long implants in augmented bone.

The aim of this narrative review is to describe treatment options for the posterior regions of the mandible and the maxilla, comparing short implants vs. longer implants in an augmented bone. The dental literature was screened for treatment options enabling the placement of dental implants in posterior sites with a reduced vertical bone height in the maxilla and the mandible. Short dental implants have been increasingly used recently, providing a number of advantages including reduced patient morbidity, shorter treatment time, and lower costs. In the posterior maxilla, sinus elevation procedures were for long considered to be the gold standard using various bone substitute materials and rendering high implant survival rates. More recently, implants were even placed without any further use of bone substitute materials, but the long-term outcomes have yet to be documented. Vertical bone augmentation procedures in the mandible require a relatively high level of surgical skill and allow the placement of standard-length dental implants by the use of autogenous bone blocks. Both treatment options, short dental implants, and standard-length implants in combination with vertical bone augmentation procedures, appear to result in predictable outcomes in terms of implant survival rates. According to recent clinical studies comparing the therapeutic options of short implants vs. long implants in augmented bone, the use of short dental implants leads to a number of advantages for the patients and the clinician.

Rehabilitation of the Atrophic Posterior Maxilla Using Splinted Short Implants or Sinus Augmentation with Standard-Length Implants: A Retrospective Cohort Study.

To retrospectively compare short implants (6 to 8 mm) (short group) to standard-length implants (≥ 11 mm) inserted in combination with a lateral sinus elevation procedure (sinus group), supporting partial fixed prostheses in the atrophic posterior maxilla. Records of 118 patients treated with fluoride-modified implants in the atrophic posterior maxilla between January 2009 and December 2011 were screened in two private practices. Two to four implants were placed in each patient and loaded after 5 to 6 months with partial fixed prostheses. Patients were followed for at least 3 years after implant placement. Patients were contacted and invited for clinical and radiologic follow-up examinations. Outcome measures were implant failures, complications, soft tissue parameters, and marginal bone levels. Fisher exact and unpaired t tests were used to compare proportions and means at the .05 level of significance. A total of 101 patients attended the examination: 53 (112 implants) in the sinus group and 48 (109 implants) in the short group. The mean observation period was 47.03 ± 7.46 months for the sinus group and 44.18 ± 6.42 months for the short group. Ten surgical complications occurred in nine patients of the sinus group versus only one complication in the short group; the difference was statistically significant (P = .01). Six implants failed in five patients of the sinus group versus two implants in two patients of the short group. At follow-up, mean marginal bone loss was 0.64 ± 0.58 mm in the sinus group vs 0.48 ± 0.5 mm in the short group. No significant difference was observed in terms of implant failures, prosthetic complications, soft tissue parameters, or marginal bone loss between the two groups. Within the limitations of this study, both techniques showed similar medium-term outcomes, but short implants provided advantages in terms of a reduced number of surgical complications.

Mini-invasive Implant Placement in Combination with Maxillary Sinus Membrane Perforation During Transcrestal Sinus Floor Elevation: A Retrospective Study.

The aim of this retrospective study was to report preliminary outcomes of a modified technique for transcrestal sinus floor elevation with simultaneous implant placement. A total of 165 implants were placed in 110 patients using a modified Summers technique. During implant site preparation, after fracturing the sinus floor, a small perforation of the membrane was made using the first osteotome. After grafting with anorganic bovine bone mixed with venous blood, standard-length implants were inserted. The prosthetic phase occurred after 4 to 5 months. Patients were followed for at least 2 years after loading. During the follow-up, sinus condition was assessed by cone beam computed tomography. Periapical radiographs were taken to assess graft height and peri-implant bone levels. Three implants failed within 2 months of placement, yielding an overall implant survival of 98.2%. The mean follow-up was 38.3 months (range: 28 to 60 months) from placement. All other implants were stable and peri-implant soft tissues were healthy throughout the observation period. Peri-implant bone loss averaged 0.62 ± 0.26 mm after 1 year of function. No biologic or biomechanical complications occurred. No evidence of graft material dispersion into the sinus space was detected, except for two cases that resolved spontaneously. After 1 year of loading the graft height averaged 4.8 ± 1.3 mm above the sinus floor level. In the presence of sinus membrane perforation, the proposed modified osteotome technique may allow a predictable rehabilitation of the atrophic posterior maxilla by means of standard length implants without the occurrence of adverse events.