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

Survival Rates of Short Dental Implants (≤6 mm) Used as an Alternative to Longer (>6 mm) Implants for the Rehabilitation of Posterior Partial Edentulism: A Systematic Review of RCTs

Short dental implants have been proposed as an alternative treatment option to bone regeneration procedures for the rehabilitation of resorbed alveolar ridges. The aim of this paper was to systematically review randomized controlled trials (RCTs) comparing short implants (≤6 mm) and longer implants (>6 mm) in atrophic alveolar ridges in terms of implant survival rates, peri-implant marginal bone loss (MBL), prevalence of peri-implantitis and technical complications. A thorough electronic search was performed until September 2023. RCTs with follow-up of at least 1-year post-loading comparing short implants with rough surfaces to longer implants in the posterior jaws of systemically and periodontally healthy, partially edentulous adults were considered. Studies with incomplete information on the number of patients, follow-up or definition of "short implants" were excluded. The revised Cochrane risk-of-bias tool for randomized trials was used for Risk of bias assessment. Fixed-effects meta-analysis of the selected studies was applied to compare the outcome variables. Random-effect meta-analysis was performed, on the basis of within-study comparisons. In total, 16 articles were selected for meta-analysis and incorporated 408 short implants and 475 longer implants inserted in 317 and 388 patients, respectively. The survival rates of longer implants in pristine or augmented bone were significantly increased compared to short implants (95%CI: 2-5%, p < 0.001). Standard-length implants displayed increased, although non-statistically significant MBL (95%CI: -0.17-0.04, p > 0.05), and prevalence of peri-implantitis (95%CI: 0-5%, p > 0.05). No statistically significant differences were observed between short and long implants in terms of technical complications (implant-level 95%CI: -4-6%, p > 0.05). Short implants represent a promising alternative treatment option for the rehabilitation of posterior jaws to avoid additional bone augmentation procedures. Nonetheless, they should be selected cautiously due to a potentially limited survival rate compared to longer implants. A major limitation of this study is the variability in the included studies regarding sample size, patient profile, type of bone, loading protocol, definition of peri-implantitis, among others. This study received no external funding. The study protocol was registered in PROSPERO (CRD42023485514).

Effects of the Application Local Zoledronic Acid On Different Dental Implants in Rats On Osseointegration

Objective

Recently, a lot of research has been done around the world to popularize the osseointegration of dental implants. In this study, it was investigated the effect of local zoledronic acid application on implants with machined (MAC), resorbable blast materials (RBM), sandblasted and acid-etched (SLA) surface implants integrated in rat tibias.

Methodology

A total of 60 female Wistar rats weighing between 270 and 300 g were used in the study. The rats were passing divided into six classes: controls; MAC (n = 10), RBM (n = 10), SLA (n = 10), and local zoledronic acid (LZA) applied groups; LZA-MAC (n = 10), LZA-RBM (n=10) and LZA-SLA (n = 10) and implants were surgically placement into rat tibias in general anesthesia. After a four-week experimental period, the biomechanical bone implant connection level was determined with reverse torque analysis.

Results

Osseointegration levels were detected highly in SLA and RBM surface compared with the machined surfaced implants in both control and treatment groups (p < 0.05). Additionally, local application of zoledronic acid in both three groups; implants increased the biomechanic osseointegration level compared with the controls (p < 0.05).

Conclusion

In this research, we observe that the local application of the zoledronic acid could increase the osseointegration, and RBM and SLA surface could be better than machined surfaced implants in terms of bone implant connection. In addition, local application of zoledronic acid may be a safer method than systemic application.

Inferior alveolar nerve repositioning surgical techniques and outcomes - a systematic review

Inferior alveolar nerve (IAN) lateralization (IANL) or transposition (IANT) are both techniques allowing for dental implant placement in posterior atrophic mandibles. The aim of this study was to systematically review the implant survival rate and the complications associated with IAN reposition techniques with simultaneous implant placement in atrophic posterior mandibles. This systematic review was conducted following PRISMA guidelines (Preferred Reporting Items for Systematic review and Meta-Analysis). The review was designed to answer the following PICO question: Is IAN repositioning (I) a safe and efficient technique (O) to treat patient looking for fixed dental rehabilitation of an atrophic posterior mandible (P). Thirty-three articles were reviewed, including a total of 899 patients, and approximately 950 IAN repositioning procedures. Dental implant survival rate ranged between 86.95% and 100% with a mean dental survival rate of 90.16%. Among the 269 patients who underwent IANT, there were 93% immediate neurosensory disturbance, and 15% persistent neurosensory disturbance. Among the 350 patients who underwent IANL, there were 93% immediate neurosensory disturbance, and 6% persistent neurosensory disturbance. IANT and IANL are reliable techniques allowing safe dental implant placement in atrophic posterior mandible with high patient satisfaction. IANL seems to cause less persistent neurosensory disturbances compared to IANT. The level of evidence is poor due to the high number of bias present in the included studies. IAN neurosensory disturbance assessment should be better homogenized in order to increase comparability.

Comparing short implants to standard dental implants: a systematic review and meta-analysis of randomized controlled trials with extended follow-up

PURPOSE

To compare the difference of marginal level changes (MBL), implant failure (IF), biological and prosthetic complications (BC and PC), and prosthetic failure (PF) of short implants (SH) and standard implants (ST).

MATERIALS AND METHODS

Electronic searches (PubMed, Web of Science, EMBASE, Scopus, Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov) and manual searches were performed to identify all randomized controlled trials (RCTs) evaluating SH to ST. Applying Stata, a meta-analysis was conducted on the weighted mean difference (WMD) and standardized mean difference (SMD) of MBL and the risk difference (RD) of the secondary outcome.

RESULTS

Twenty-four articles were involved in the present study. There were statistically significant differences in MBLs, preferring short implants in the maxilla (WMD: -0.147 (CI: -0.224, -0.070), I2: 76.6%; SMD: -0.757 (CI: -1.226, -0.289), I2: 89.2%) and in the mandible (WMD: -0.377 (CI: -0.656, -0.098), I2: 85.8%; SMD: -0.811 (CI: -1.418, -0.204), I2: 78.8%). There were no significant differences in IF (RD: 0.011 (-0.002, 0.023), I2: 0.0%), PF (RD:0.003 (-0.007, 0.014), I2: 0.0%), and PC (RD:0.001 (-0.008, 0.010), I2: 0.0%). There were significantly higher biological complications (RD: -0.071 (-0.106, -0.036), I2: 0.82.9%) for ST compared to SH in both jaws up to a 10-year follow-up.

CONCLUSION

SH and ST had comparable overall outcomes, but short implants had less marginal bone loss and lower biological complications. However, more research is needed to confirm these findings.

In-Block Lateralization as a New Technique for Mobilization of the Inferior Alveolar Nerve: A Technique Case Series

The edentulous atrophic posterior mandible is often a great challenge for implant rehabilitation. Although a number of treatment options have been proposed, including the use of short implants and surgical grafting techniques, in cases of severe bone atrophy, techniques for mobilization of the inferior alveolar nerve (IAN) have been shown to be efficient, with good results. Four female patients underwent IAN lateralization for prosthetic rehabilitation of the posterior mandible from 2013 to 2019, with 3 years to 5 years and 3 months of follow-up. This case series describes a new technique for mobilization of the IAN, named in-block lateralization, to facilitate access to the IAN and to reduce nerve manipulation. The implant is immediately installed (allowing nerve lateralization in unitary spaces), and the original mandibular anatomy is restored with autogenous bone from the original bed during the same surgical procedure. When well indicated and well performed, this new approach provides better and easier visualization of the IAN and safer manipulation aiming to achieve good results for implant stability and minimal risk of neurosensory disturbances, allowing rehabilitation even in unitary spaces.

The effects of metformin on the bone filling ration around of TiAl6Va4 implants in non diabetic rats

Objectives

In this research it was aimed to that evaluation of the effects of systemic metformin administration on the periimplant bone tissue response of TiAl₆Va₄ implants in experimental rat model.

Materials and method

Firstly TiAl₆Va₄ implants were inserted surgically in the metaphyseal part of the tibial bone and after, the rats were randomly separated into two groups: Controls (CNT) (n = 10) and Metformin group (M) (n = 10). No additional treatment was applied to the controls during the 4-week experimental period. Rats received 40 mg/kg metformin in every day during the four week experimental period in M group. At the end of the 28-day follow-up period, the TiAl₆Va₄ implants with surrounding bone were used for the histopathologic analysis. To analysis of the datas between M and CNT Student-T Test was used.

Result

Periimplant bone tissue filling ratios (%) were detected higher in M group compared with the CNT (P < 0.05).

Conclusion

Systemic administration of metformin may increases titanium implant osseointegration in non-diabetic rats.

Clinical Performance of Short Expandable Dental Implants for Oral Rehabilitation in Highly Atrophic Alveolar Bone: 3-year Results of a Prospective Single-Center Cohort Study

Background and Objectives: Oral health-related quality of life (OHRQOL) is compromised during the post-implant healing period, especially when vertical augmentation is required. A long-term trial sought to evaluate a short dental implant system with an apically expandable macro-design. Materials and Methods: Over 4.5 years, patients with limited vertical alveolar bone were consecutively recruited into this prospective cohort study. Implant success rate, OHRQOL (Oral Health Impact Profile (OHIP)-14), implant stability, and crestal bone changes were evaluated. Results: Data from 30 patients (mean age: 64.6 years, range 44–83) were analyzed, which related to 104 implants (53 in the maxilla, 51 in the mandible). Over the mean follow-up (42.6 ± 16.4 months), the implant success rate was 94.7% in the mandible (two implants lost) and 83.6% in the maxilla (four implants lost; p = 0.096), and the prosthetic success rate was 100%. The median OHIP-14 scores improved from 23 (interquartile range (IQR) 9–25.5) to 2 (IQR 0–5; p < 0.001). The mean implant stability quotient (ISQ) was 71.2 ± 10.6 for primary stability and 73.7 ± 13.3 (p = 0.213) for secondary stability, without significant maxilla-versus-mandible differences (p ≥ 0.066). Compared to the baseline, median crestal bone changes after loading were 1.0 mm (IQR 0–1.3) and 1.0 mm (IQR 0.2–1.2) in the maxilla and mandible (p = 0.508), respectively, at the end of the first year, 1.1 mm (IQR 0–1.3) and 1.0 mm (IQR 0.1–1.2) (p = 0.382), respectively, at the end of the second year, and 1.2 mm (IQR 0–1.9) and 1.1 mm (IQR 0.1–1.2) (p = 0.304), respectively, at the end of the third year. Conclusions: In patients with limited vertical bone height, short implants with optimized macro-design constitute a reliable method for functional rehabilitation, avoiding extensive alveolar bone augmentation.

Extra short 4mm implants used to rehabilitation of atrophic posterior mandible. A serial case reports

Rehabilitation of patients through implants in areas with severe bone resorption in the posterior mandible is a challenge in implant dentistry. In this context, extra short implants configure a treatment option for this type of patient, as they can avoid increased financial cost, treatment time and patient morbidity. The present study evaluated the marginal bone stability in individualized extra-short implants for masticatory function in the posterior mandible. Using digitized periapical radiographs of 13 extra-short implants performed on 7 patients. The mesial and distal regions of each implant were selected, from the bone crest to the region parallel to the apex, and the bone stability of this crest was measured using the Image J software immediate T1 and 1 year after rehabilitation (T2). The height of the bone crest remained stable, showing no statistically significant difference between T1 and T2 (p> 0.005) for both the mesial bone crest and the distal bone crest in individual or united crowns rehabilitation. Marginal bone stability was observed in extra short implants, corroborating the biological and biomechanical stability of these implants presented in the literature. Despite the limited sample size and proservation time, extra-short implants are predictive treatment options for patients with severe bone atrophy in the posterior mandible. Key words:Extra-short implants, marginal bone loss, mandibular bone atrophy.

The adjuvant use of plasma rich in growth factors in the inferior alveolar nerve repositioning technique

Purpose

To describe the outcomes of the adjuvant use of plasma rich in growth factors (PRGF) in the inferior alveolar nerve repositioning surgery.

Material and methods

A retrospective report of three cases was conducted in a single private dental clinic. The variables were the residual alveolar bone height, the surgical complications, the occurrence of neurosensory complications, the marginal bone stability and the implant survival. A descriptive statistical analysis was performed.

Results

Three inferior alveolar repositioning were performed with the adjuvant use of PRGF. The residual alveolar bone height was 2.2 ± 0.14 mm. All patients underwent uneventful healing with no symptoms of neurosensory complications neither implant failure. The marginal bone loss was 0.1 ± 0.4 mm

Conclusions

The preventative and adjuvant use of PRGF in inferior alveolar nerve repositioning need to be assessed in prospective studies with a larger sample size.

Alveolar Ridge Preservation after Tooth Extraction Using Different Bone Graft Materials and Autologous Platelet Concentrates: a Systematic Review

Objectives

To review and assess the efficiency of different post extraction socket preservation techniques.

Material and Methods

An electronic literature search was performed on the MEDLINE and Embase databases. The review included human studies published between from January 1^st, 2007 to January 1^st, 2018, in English. Outcome measures included dimensional changes and/or histological evaluation of alveolar bone.

Results

Twenty-six full text articles were reviewed, 16 of which met the inclusion criteria and were selected for the study. Autogenous tooth graft prevented vertical resorption the most: -0.28 (SD 0.13) mm, observation period (OP): 4 months, while the least effective approach was beta tri-calcium phosphate (β-TCP): -1.72 (SD 0.56) mm, OP: 4 months. Estimating horizontal resorption, the most effective technique was biphasic calcium sulphate (BCS) with β-TCP and hydroxyapatite (HA) - BCS + TCP + HA: 0.03 (SD 2.32) mm, OP: 4 months, while β-TCP was the least efficient: -1.45 (SD 0.4) mm, OP: 4 months. Evaluating residual graft particles (RG) and newly formed bone (NFB) ratio the best results were achieved with demineralized freeze-dried bone allograft: RG: 8.88%, NFB: 38.42%, OP: 5 months, whereas magnesium-enriched hydroxyapatite was least effective: RG: 40.82%, NFB: 31.85%, OP: 4 months.

Conclusions

This review revealed that even though there are numerous types of biomaterials for socket preservation none of them can completely stop alveolar bone loss after tooth extraction. Furthermore, lack of information about qualitative evaluation of bone was noticed indicating that further studies regarding this topic are needed.

Primary and Secondary Stability of Single Short Implants

PURPOSE

This prospective cohort study assessed the effect of bone quality on the primary and secondary stability of single short implants placed in the posterior region.

MATERIALS AND METHODS

A total of 39 short implants (4.1 × 6-mm long) were placed in the posterior region of the maxilla or mandible in 18 patients. Bone quality was classified into type I, II, III, or IV as assessed intrasurgically. Primary implant stability was measured with insertion torque, damping capacity (PTV values), and resonance frequency analysis (ISQ values). Secondary stability was measured by ISQ and PTV at abutment installation. Data were analyzed by using repeated-measures ANOVA and Tukey's test, Kruskall-Wallis test, and Spearman correlation tests.

RESULTS

Implants placed in bone type IV had significant lower insertion torque and ISQ values as well as higher PTV values than in bone types I to II (P < 0.05). The mean ISQ values were higher at abutment installation than at implant placement (P < 0.05), regardless the bone type. The assessment methods of implant stability showed a moderate correlation.

CONCLUSIONS

Bone quality influences both the primary and secondary stability of single short implants in the posterior region.

Influence of short implants geometry on primary stability

BACKGROUND

A correct design is needed in short implants to improve primary stability (PS) in low quality bone. This study aimed to compare PS of double thread and single thread short implants.

MATERIAL AND METHODS

Thirty implants with single thread design (PHI/SHORT-I) and 30 implants with double thread design (PHIA/SHORT-I) (Radhex®, Inmet-Garnick S.A., Guadalajara, Spain) were placed in 30 randomly selected bovine ribs. PS was assessed in implant stability quotients (ISQ) and periotest values (PV) with Osstell™ and Periotest® devices, respectively. Computed tomographies of the ribs were taken and bone quality was evaluated in Hounsfield Units (HU) using Ez3D Plus software (Vatech Co., Korea). Only implants placed in low quality bone according to Misch and Kircos classification were selected (D3 bone: 350-850 HU; and D4 bone: 150-350 HU). Ten implants were not included in the study for being placed in D1 and D2 bone. Finally, 50 implants were selected: 17 and 9 PHI/SHORT-I in D3 and D4 bone respectively, and 15 and 9 PHIA/SHORT-I in D3 and D4 bone respectively.

RESULTS

The one-way ANOVA showed statistically significant differences in ISQ (61.35 ± 4.77 in PHI/SHORT-I and 66.43 ± 4.49 in PHIA/SHORT-I, P<0.005) and PV (-2.76 ± 0.8 and -4.11 ± 1.24 respectively, P<0.005) between two implant designs in D3 bone, and statistically significant differences in ISQ (53.44 ± 3.34 in PHI/SHORT-I and 60.56 ± 1.53 in PHIA/SHORT-I, P<0.0001) and PV (1.13 ± 0.95 and -2.5 ± 0.61 respectively, P<0.0001) between two groups in D4 bone.

CONCLUSIONS

Double thread design short implants resulted to have higher PS in comparison with single thread design short implants in D3 and D4 bone.

Do short implants have similar survival rates compared to standard implants in posterior single crown?: A systematic review and meta-analysis

BACKGROUND

Short implants have been presented as an option for posterior rehabilitation in cases of poor bone height.

PURPOSE

To compare the survival rate of short implants and standard implants when used in posterior single crowns, in addition to reporting marginal bone loss, prosthetic failures, and surgical complications.

MATERIALS AND METHODS

Electronic search (PubMed, LILACS, Cochrane Library, Scopus, and Web of Science) and hand search were performed to identify all randomized controlled trials (RCTs) and controlled clinical trials (CCTs) that evaluated both short and standard implants in posterior single crowns.

RESULTS

Out of 345 articles identified by both electronic and hand search, four studies were selected (one CCT and three RCTs). The meta-analysis for the survival rate showed that there was no significant difference between the short implants and the standard ones (P = 1.00; RR:1.00; CI:0.97-1.03) performed with three RCTs for a one-year follow-up. The mean marginal bone loss ranged from 0.1 mm to 0.54 mm. Only one study reported the presence of prosthetic failures and surgical complications.

CONCLUSIONS

The survival rate of short implants was similar to the standard ones in posterior single crowns, for the one-year follow-up period. They also presented low surgical complications, prosthetic failures and marginal bone loss, being a predictable treatment for single rehabilitation in posterior tooth loss.

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

Objectives

Test 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 Methods

A 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.

Results

Six 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).

Conclusions

Short 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.

Novel expandable short dental implants in situations with reduced vertical bone height-technical note and first results

PURPOSE

Short implants often have the disadvantage of reduced primary stability. The present study was conducted to evaluate the feasibility and safety of a new expandable short dental implant system intended to increase primary stability.

METHODS

As a "proof of concept", a prospective clinical cohort study was designed to investigate intraoperative handling, primary and secondary implant stability (resonance frequency analysis), crestal bone changes, implant survival and implant success, of an innovative short expandable screw implant. From 2014 until 2015, 9 patients (7-9-mm vertical bone height) with 30 implants (length 5-7 mm, diameter 3.75-4.1 mm) were recruited consecutively.

RESULTS

All 30 implants in the 9 patients (age 44 to 80 years) could be inserted and expanded without intraoperative problems. Over the 3-year follow-up period, the implant success rate was 28/30 (93.3%). The mean implant stability quotients (ISQ) were as follows: primary stability, 69.7 ± 10.3 ISQ units, and secondary stability, 69.8 ± 10.2 ISQ units (p = 0.780), both without significant differences between the maxilla and mandible (p ≥ 0.780). The mean crestal bone changes after loading were (each measured from the baseline) as follows: in the first year, 1.0 ± 0.9 mm in the maxilla and 0.7 ± 0.4 mm in the mandible, and in the second year, 1.3 ± 0.8 mm and 1.0 ± 0.7 mm, respectively.

CONCLUSIONS

Compared to other prospective studies, in this indication, the success rate is acceptable. Implant stability shows high initial and secondary stability values. The system might present an extension of functional rehabilitation to the group of elderly patients with limited vertical bone height. Further long-term investigations should directly compare this compressive implant with standard short implants.

Transalveolar Osteotomy of the Mandibular Canal Wall for the Treatment of Severely Atrophied Posterior Mandible

PURPOSE

Treatment of severe bone atrophy of the posterior mandible requires an advanced surgical bone augmentation technique. This report describes a minimally invasive approach for a residual alveolar height less than 5 mm.

MATERIAL AND METHODS

A retrospective case series was conducted in a single private dental clinic. Outcome variables were dental implant survival rate, intraoperative complications, occurrence of neurosensory disturbances, and marginal bone loss. Descriptive analysis was performed for patients' demographic data, postoperative healing, and implant details. Kaplan-Meier method was used to assess the implant survival rate.

RESULTS

The mean age of the 19 patients was 60 ± 13 years. Twenty-eight implants (5.5 mm long) were placed in a residual alveolar bone height of 4.5 ± 0.6 mm. The implant survival rate was 96% at 5-year follow-up.

CONCLUSIONS

Extra-short implants and transalveolar preparation of the inferior alveolar cortical bone could be a safe and effective treatment of severe mandibular atrophy.