Ultrashort Implants Research Articles

Immediate versus conventional loading in short and ultra-short implants: a protocol design.

After tooth extraction, inevitable resorption of the postextraction socket occurs. Placing an immediate implant does not fully preserve the bone integrity of the socket. Preservation techniques cannot avoid alveolar resorption. In residual atrophies, bone augmentation techniques are necessary for subsequent rehabilitation with implants. The aim of this study was to propose a protocol of immediate loading in short implants as an alternative to bone augmentation techniques, comparing the immediate versus conventional loading, evaluating peri-implant bone loss, the biological and prosthetic complications, the survival of the implant and prosthesis and the patient satisfaction after one year. This study consists of a randomized controlled clinical trial. For implant planning, periapical intraoral radiographs and Cone Beam Computed Tomography will be used. All patients will receive Straumann Group® (Basel, Switzerland) titanium-zirconia implants with a 4.1mm or 4.8mm diameter and a 4 mm or 6 mm length. The expected results show similar or even minor bone loss, biological and prosthetic complications, identical or even better survival of the short implants with immediate loading, and greater satisfaction. Short implants demonstrate similar survival to conventional length implants, with comparable or even minor biological and prosthetic complications and bone loss. Immediate loading gives satisfactory results similar to conventional loading, with similar biological and prosthetic complications, and generally depends on poor hygiene levels. Bone loss is even less, and the satisfaction increases.

PRIMARY AND POST-OSSEOINTEGRATION STABILITY OF SHORT (ULTRA-SHORT) IMPLANTS ON EDENTULOUS ATROPHIED DISTAL SEGMENTS OF THE MANDIBLE - AN INDICATOR OF IMMEDIATE OR DELAYED LOAD

Introduction. The issue of determining the possibility of immediate or long-term load on the selected type of implants, which will ensure the predictable result of their long-term functionality, remains an ongoing discussion. The results of the resonance frequency analysis, which perfectly characterize the stability of short and ultrashort implants at all stages of their osseointegration and post-osseointegration periods, can serve as such an indicator basis. Aim. To analyze the primary and post-osseointegration stability of short (ultra-short) implants placed by the methods at the level of the cortical bone layer and subcortically in case of bone atrophy caused by acquired final dentition defects. Materials and methods. The primary and post-osseointegration stability of thirty-nine dental short (h = 6.5 mm X b = 4.0 mm – 20 pieces) and ultra-short (h = 5.5 mm X b = 4.0 mm – 19 pieces) implants placed on the edentulous distal segments of the human mandible was studied. According to the clinical assessment that met the aim and objectives of this study, all patients were divided into four study groups: the first group consisted of patients with a preserved dentition who did not require dental implantation; the second group – 25-45 years old, the third group – 46-60 years old, and the fourth group – ≥ 61 years old. Using the resonance frequency analysis (RFA) method by Penguin Instruments, the results were interpreted in declarative units of measurement – the implant stability quotient (ISQ). Results. The installed short (ultrashort) implants, according to the methodology by the level of the cortical layer of bone tissue, are characterized by their high primary stability by anti-rotational force: in the second group of the study (25-45 years old) with a mean number (M) of 87.0 and an error of the mean (± m) of ± 2.3 ISQ; in the third group (46-60 years old) – 76.4 ± 3.0 ISQ; in the fourth group (persons ≥ 61 years old) – 69.8 ± 4.8 ISQ. Low values of primary stability were obtained in implants installed by the subcortical implantation technique in the second age group of the study and amounted to 59.6 ± 2.7 ISQ with a slight increase to 66.0 ± 4.1 ISQ in the third group and 71.7 ± 4.2 ISQ in the fourth group of the study, which do not guarantee the prognosis of functional redistribution of the supra occlusion immediate load on the biological basis, with further preservation of the course of normal physiological processes in the bone tissue around the implanted implants. Conclusions. Rehabilitation of patients with bone atrophy caused by the loss of the masticatory group of teeth is possible using short (h = 6.5-6.0 mm) and ultra-short (h = 5.5 mm) implants, with clinical justification for the choice of methods of immediate or post-osseointegration load, with a detailed resonance frequency analysis as a priority and reliable method – an effective indicator of their stability, at all stages of clinical rehabilitation of patients.

Analysis of ultra-short implants with different angulations: a retrospective case-control study with 2 to 9years of follow-up.

Does the angulation of ultrashort implants influence the stability of the peri-implant bone? The present study aimed to evaluate the effectiveness of non-axial ultrashort implants after 2 to 9years of follow-up in resorbed alveolar ridges. All partially edentulous patients with ultrashort implants (< 6mm) used in the posterior region of an atrophic mandible or maxilla, to support partial dentures in conjunction with standard implants, were included in this study. Peri-implant bone loss, success and survival rates, crestal bone levels, crown-to-implant ratio and implant angulation were measured for each implant. Implants were divided into two groups: straight implants with angulation < 17° (control group) and tilted implants with angulation > 17° (test group). Statistical analysis was used to find any significant differences between the two study groups and to investigate significant linear correlations among all the variables (p = 0.05). A total of 42 ultrashort implants with a mean of 4years of follow-up were included: 20 ultrashort axially loaded implants and 22 tilted implants. Mean crestal bone levels from baseline loading to maximum follow-up did not reveal statistical differences in regard to PBL; mean success and survival rates were 100% in all groups. PBL, success and survival rates of axial ultrashort implants and tilted ultrashort implants are comparable to those of conventional implants. This retrospective study revealed that ultrashort implants, even when placed with an angulation > 17°, can safely be used to support partial fixed prostheses. Further prospective clinical studies with larger samples and prospective design are needed to confirm these findings.

Evaluation of short and ultra-short dental implants in challenging clinical situations of resorbed ridges: A narrative review

ABSTRACT Background: Dental implant treatment has gained widespread acceptance as a reliable method for replacing lost teeth. Nevertheless, the favorable outcome of implant therapy hinges on having adequate bone quality and quantity. Individuals with restricted bone height or density pose a unique challenge for implant placement. Short and ultra-short dental implants offer an alternative solution for such patients, as they necessitate less vertical bone height and can mitigate the necessity for supplementary bone augmentation procedures. Aim: This narrative review was conducted to understand the different types of short and ultra-short implants, their indications and contraindications, and their prosthetic considerations, summarizing the current literature on the clinical outcomes, success rates, and potential complications. Methods: Research publications were searched on search engines such as EBSCO, EMBASE, PubMed, Web of Science, and Cochrane library databases, and the articles published from January 1988 to December 2022 with terms such as “short implants, ultra-short implants, atrophic ridge, and alveolar ridge augmentation” were collected. Results: A total of 10 articles were collected, and they were further used to formulate this review. Despite their constraints, short and ultra-short implants have demonstrated comparable clinical results to conventional implants in specific scenarios and provide several advantages, such as reduced surgical time, lower costs, and decreased risk of anatomical complications. Discussion: Short and ultra-short dental implants are used when regular ones are not feasible. They increase stability by enhancing bone contact. They work well for various dental prostheses, especially for those who cannot use removable options. While not recommended for everyone, they can be successful in many cases. Factors such as implant shape, surgical technique, and prosthetic considerations play a key role in their success. Studies show high survival rates for short implants, making them a reliable choice for specific situations. They offer a less invasive and cost-effective alternative in challenging cases. Conclusion: As technology and designs continue to advance, the adoption of short and ultra-short implants is expected to see a rise in implant dentistry. It is imperative to exercise careful patient selection, comprehensive treatment planning, and precise execution of both surgical and prosthetic techniques for the successful implementation of implant therapy with short and ultra-short implants.

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

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. 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). 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). 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.

Resonance frequency analysis – indicator of post-implantation morphology of mandibular bone tissue

This article describes the role of resonance frequency analysis (RFA) as an indicator of the quality of primary implant stability, which is the basis of the goal and confirmed by the results of a clinical case – odontological implantation on edentulous segments of atrophied bone tissue on the right side of the mandible, taking into account the topographic features of its canal, using ultra-short (h = 5.5 mm) implants.&#x0D; Aim. To highlight the role of resonance frequency analysis during surgical interventions using short (ultrashort) implants in predicting their primary stability and preserving the normal morphology of the mandibular bone tissue.&#x0D; Materials and methods. The primary stability of 17 dental implants in seven patients was determined using the Penguin Instruments (RFA) technique in declarative units of measurement – the implant stability quotient (ISQ). Values in the range of 75 ISQ meant that the implant had adequate primary stability and could receive and distribute the immediate load on the bone tissue of the edentulous segment.&#x0D; Results. Following the stages of preparation, 17 ultra-short (h = 5.5 mm × b = 4.0 mm) implants were placed on the edentulous segments of the mandible without an incisional osteotomy path according to the patient rehabilitation protocol. We used the method of resonance frequency analysis to obtain a value of high primary stability of two short subcortical implants in the projection of tooth 4.7 – 92 ISQ and the projection of tooth 4.6 – 90 ISQ. On the 3rd day of the clinical stage of fixation of the supraconstruction, RFA measurements were performed, the values of which showed a significant decrease in the stability quotient of the installed implants in the projection of tooth 4.7 – 61 ISQ and in tooth 4.6 – 74 ISQ. This result made it necessary to revise the rehabilitation plan, adjust the medical prescription sheet and decide to postpone the placement of the all-milled restorative structure on the implants.&#x0D; Conclusions. The RFA study indicates not only the primary stability of implants but also a full-fledged stage-bystage clinical prognosis of the further functionality of a prosthetic structure based on short implants with proper preservation of the morphological functionality of bone tissue.

Investigating the optimal design of all-on-four technique adopting finite element analysis: the aspect of framework material, kind and position of implants

Nowadays, the dental implant surgery is a sophisticate and accurate sector with techniques increasingly innovative such as rapid prototyping, guided implant surgery and stem cell-based approaches. An example is certainly the use of multiple implants (4–6), instead of several prosthesis in case of human edentulous condition. The aim of this research is to investigate the mechanical behavior of the All-on-Four technique for different boundary conditions such as the value of load, framework material, type and position of implant. The goal was essentially trying to find out, by the application of structural static Finite Element Analysis (FEM), the best design for this specific treatment. After that, a stress-life fatigue numerical analysis was conducted for the optimal configuration in order to estimate the fatigue life in accordance with both Gerber and Goodman mean stress theory. The coupling involved the implants supported by an arch and a human mandible composed of cortical and cancellous part. After the simulations, it was found that the stress/strain field was very sensitive to the boundary conditions imposed. In particular, the position of the implants and the material framework yielded different responses depending on the implant design. Finally the use of ultrashort implants provided a significant decrease in the developed efforts than the long ones if the first premolar position was assumed. More specific, the stress peaks were in the range 100–225MPa for the implants, 300–537MPa for the framework, 50–124MPa for the cortical bone and 3–35MPa for the cancellous bone and they were located essentially in the abutment-framework connection as much as in implant neck-bone coupling. The best design saw the presence of ultra-short implant, first premolar position and Co-Cr alloy as framework material. The fatigue test confirmed the stability of the structure even with dynamic loads, but critical spots were present in the framework. In conclusion, the All-on-Four technique is a valid and safe alternative, even in case of ultrashort implants, for human edentulism care.

Clinical Protocol for Implant-Assisted Partial Removable Dental Prostheses in Kennedy Class I: A Case Report

Patients with Kennedy Class I are usually treated with clasp-retained removable partial dentures (RPDs) as the prosthetic gold standard. For additional stabilization of the RPD, clinicians are often confronted with the question of secondary implant placement, which requires the fabrication of new prostheses. This case report is part of an ongoing multi-center randomized controlled study (RCT) investigating conventional RPDs without and with supplementary implants. A design of the RPD framework, including matrix housings, is crucial to enable subsequent implant retention or support. Ultra-short implants (Straumann TL 4.1 × 4 mm) offer the opportunity for additional support and retention in the edentulous posterior region, where bone availability is often reduced. This future-oriented and minimally invasive approach with virtual treatment planning and guided implant surgery offers the possibility of simplified functional and cost-effective aftercare.

Short and Ultra-Short Implants, in Association with Simultaneous Internal Sinus Lift in the Atrophic Posterior Maxilla: A Five-Year Retrospective Study.

Recent short-term studies suggested the use of short and ultra-short implants in association with a modified osteotome sinus floor elevation (internal sinus lift) technique for the treatment of edentulous resorbed posterior maxilla. The aim of this retrospective study was to investigate this hypothesis in locking-taper implants with a mid-term follow-up of 5 years. Overall, 155 implants (32, 100, and 23 of, respectively, 5.0 mm, 6.0 mm, and 8.0 mm length) were positioned in the atrophic upper maxilla of 79 patients, and 151 implants were loaded with single crowns. Overall implant survival after 5 years was 94.84%. Implant survival for each length group was 93.75%, 94%, and 100% for 5.0, 6.0, and 8.0 mm length, respectively. Preoperative residual crestal bone height of 4.45 (1.3) mm increased to 9.25 (2.13) mm after implant placement and settled at 6.35 (1.73) mm after loading and at 5.25 (1.68) mm at follow-up. Elevation of the Schneiderian membrane was 4.8 (2.46) mm after implant placement, 3.06 (1.3) mm after loading, and 1.46 (1.06) mm at follow-up. Mean variations of peri-implant crestal bone loss and first bone-to-implant contact point were, respectively, -0.36 (1.3) mm and -0.62 (1.15) mm. It can be confirmed that internal sinus lift procedure revealed stable bone gain and negligible resorption at mid-term follow-up for atrophic upper crests with reduced height.

Rehabilitation of Atrophic Mandible with Ultrashort Implants Combined with Photobiomodulation Therapy: A Split-Mouth Design Study.

Background:Atrophic edentulous mandible is a challenging clinical condition. Studies assessing the use of ultrashort implants to support overdentures are scarce; the optimum photobiomodulation (PBM) dose for enhancing osseointegration is yet unknown.Objective:This study aimed to evaluate and compare mandibular overdentures assisted by two versus four ultrashort implants with adjunctive PBM therapy using two doses.Materials and Methods:A total of 36 implants were placed in 12 edentulous male participants and they were randomly allocated to Group I (mandibular overdentures assisted by two ultrashort implants) or Group II (by four ultrashort implants). Fully guided implant placement was performed, and then a split-mouth design was implemented. The participants received PBM by diode laser (660 nm). Dose A (3.75 J/cm2) and Dose B (7.5 J/cm2) were applied to the right and left implant (s), respectively. Implant stability, peri-implant probing depth (PIPD), and modified gingival index (MGI) were evaluated at baseline, and at 6 and 12 months after loading.Results:After 12 months, the implant stability values were significantly higher in Group II compared with Group I (P < 0.001). A significant difference was observed in between the PIPDs of both groups (Group I: 2.35 ± 0.54 mm; Group II: 1.69 ± 0.35 mm;P= 0.001). The mean MGI values were low for both groups (Group I: 0.75 ± 0.58; Group II: 0.51 ± 0.41).Conclusions:Mandibular overdentures supported by four ultrashort implants had a more favorable clinical outcome, while PBM doses A and B were comparable in all evaluated parameters.Trial Registration:ClinicalTrials.gov Identifier: NCT03540316.

A 5-year randomized controlled clinical trial comparing 4-mm ultrashort to longer implants placed in regenerated bone in the posterior atrophic jaw.

Short implants (up to 5-mm long) have shown good results when compared to longer implants placed in augmented bone. To evaluate if 4-mm ultrashort implants could also be an alternative to bone augmentation in the severely atrophic posterior jaws. The primary aim of the study was to compare implant survival rates between study groups. Eighty partially edentulous patients with posterior atrophic jaws (5-6 mm of bone above the mandibular canal and 4-5 mm below the maxillary sinus) were included: 40 patients in the maxilla and 40 in mandible. The patients were randomized to receive one to three 4-mm ultrashort implants or one to three implants at least 10-mm long in augmented bone. Results are reported 5 years after loading with the following outcome measures: implant and prosthetic failures, complications and peri-implant marginal bone level changes. Thirty-two complications were reported for the control group in 18 patients versus 13 complications in 10 patients in the test group, the difference being not statistically significant (p= 0.103). In the augmented group, 12 implants failed in 6 patients versus 7 short implants in 6 cases, and 9 prostheses failed in the control group while 4 in the test one, without statistically significant differences (p= 1.000 and 0.363, respectively). At 5 years after loading, short implants lost on average 0.58 ± 0.40 mm of peri-implant marginal bone and long implants 0.99 ± 0.58 mm, the difference was statistically significant (p= 0.006). Four-millimeter ultrashort implants showed similar if not better results when compared to longer implants placed in augmented jaws 5 years after loading. For this reason, their use could be in specific cases preferable to bone augmentation since the treatment is less invasive, faster, cheaper and associated with less morbidity. However, longer follow-ups and larger trials are needed.

1-Year Post-loading of Short and Ultrashort Implants in Posterior Mandibular and Maxillary Regions

BACKGROUND: Short implants have been proposed as an option for management of deficient alveolar ridges without the need for complex augmentation procedures. AIM: In this study, we aim to assess the use of short and ultrashort implants for the management of deficient alveolar ridges in posterior mandibular and maxillary areas with a 1-year post-loading follow-up. METHODOLOGY: Ten patients were recruited in this trial with a total of 14 implants to be placed. The patients all needed implants in the maxillary/mandibular posterior regions for prosthetic rehabilitation with deficient alveolar ridge heights. Implants of 5 mm diameter and lengths either 6 or 8.5 mm were to be placed in the edentulous spaces after proper radiographic assessment. Two-stage surgeries were followed with ¾ months between implant placement and loading. The follow-up lasted for a year to allow for peri-implant clinical assessment and radiographic analysis. RESULTS: All patients showed uneventful healing and no infection, wound dehiscence or inflammation was noted. Prosthetic rehabilitation was successful and satisfactory to the patients. None of the cases showed excessive marginal bone loss and stability was maintained at acceptable levels to the end of the follow-up period. CONCLUSION: Within the limitations of this study, short and ultrashort implants seem like a valid option for management of posterior edentulous regions with deficient ridge heights.

Severely Atrophic Mandibles Restored With Fiber-Reinforced Composite Prostheses Supported by 5.0-mm Ultra-Short Implants Present High Survival Rates Up To Eight Years

Encouraging results have been reported for ultrashort single implants; however, long-term investigations are warranted for full-arch reconstructions. This study evaluated marginal bone loss, implant, and reconstruction survival of fiber-reinforced composite full-arch prostheses supported by 4 ultrashort implants. Patients with severely atrophic mandibles (Cawood and Howell class V and class VI) were included in this cohort study. Study predictors included time (initial and last follow-up) and vertical (epicrestally or subcrestally) and horizontal implant position (medial or lateral). Outcome variables included bone level changes over time, implant/prosthesis survival. Peri-implant bone level was measured on panoramic radiographs. Descriptive statistics, Kaplan-Meier, mixed model analysis of variance, and univariate and multivariate Cox Proportional Hazards Regression models, adjusted for multiple implants in the same patient, were used for data analyses. Eighteen patients (mean 61.22 years old), with 72 implants placed in atrophic mandibles with an average follow-up of 55.4 months (CI, ±4.6/ SD, ±10.6 months) were analyzed. The implant survival rate was 97.2% as 2 implants were not loaded due to non-osseointegration and sensorial disturbances. Average marginal bone level at baseline (1.93 mm) and at the time of last recall (1.91 mm) was not significantly different. While implants placed subcrestally showed no significant difference between baseline (1.91 mm) and last follow up bone level (2.12 mm), implants placed epicrestally demonstrated a significant reduction on their bone level over time (initial: 1.97 mm/ final:1.33 mm). Systemic disorders were a risk factor for implant survival and bone loss. Prostheses cumulative survival rate was 100% (mean observation period of 55 months). The estimated survival rate after the 96-month follow-up was 75% (1 framework fracture after 84 months). Fixed fiber-reinforced composite full-arch prostheses retained by 4 ultrashort implants showed a stable bone level and high implant/prostheses survival rates up to 8 years.

Crestal bone loss in ultrashort implants: retrospective study on two different type of fixture.

Aim This was to assess variation of mean crestal bone loss (CBL) when two different types of ultrashort implants are placed in the upper or in the lower jaw and to evaluate differences in terms of success and survival rates. Materials and methods 99 ultrashort implants were retrospectively evaluated assessing differences at three different time-points (placement, prosthetic loading, end of follow-up) in terms of CBL in the upper and lower jaw. Correlations between CBL and diameter, platform switching, site of placement (upper or lower), type of implants, clinical crown/implant ratio and anatomical crown/implant ratio were statistically performed and success and survival rate were assessed. Results Statistically significant correlations were found between CBL and implant diameter, kind of screw and anatomical crown/implant ratio at the end of follow up. No correlation was highlighted between CBL and platform switching, and site of placement (upper or lower jaw). Survival and success rates were comparable and were found to be 96.37% in the upper jaw and 94.46% in the mandible. Conclusion CBL in ultrashort implants is an issue deserving great attention, therefore to know features and behaviours of different ultrashort implants in different quality of bone and clinical conditions represents a cut above to obtain and maintaining success in this particular kind of rehabilitation.

Ultra-short versus standard-length dental implants in conjunction with osteotome-mediated sinus floor elevation: A randomized controlled clinical trial.

The ability to restore missing teeth with dental implants is dictated by the available bone and by the presence of anatomical structures. The potential to insert ultrashort implants avoids additional surgical procedures and its inherent complications. The last European Association of Dental Implantologists consensus in 2016 defined ultrashort implants and standard-length dental implants as <6 and >8 mm, respectively. The present study aimed to investigate whether single standing ultrashort dental implants (US) could provide a viable therapeutic alternative to osteotome mediated sinus floor elevation in combination with standard-length dental implants (SL) 10 mm in posterior maxillary rehabilitation with reduced bone height. The study was conducted as a prospective parallel group controlled clinical trial with a 12 month follow-up, where 48 implants were randomized into two groups; US-group (5.5 mm) and SL-group (10 mm) implants placed with osteotome-mediated sinus floor elevation. Crestal bone loss (CBL) was defined as the study's primary outcome, while implant survival, buccal bone thickness, implant stability, probing depth, gingival recession, and adverse effects were assessed as secondary outcomes. Mesial CBL was 1.13 ± 0.52 mm in SL- and 0.72 ± 0.52 mm in US-group (P=.021), while distal CBL was 1.44 ± 0.72 mm in SL- and 0.91 ± 0.69 mm in US-group at 12 months (P=.0179). Regarding implant stability, probing depth, and gingival recession there was no statistically significant difference between the two groups. Regarding implants' survival, three implants were lost in the US-while only one implant was lost in the SL-group (P=.6085; Fisher's exact test). Nevertheless, the ultrashort implants were associated with a tripling of the failure rate and uncertainty where the true failure rate is uncertain (relative risk 3.0; confidence interval 0.3-26.8). Within the current trial's limitations, US-appear appear promising as they are associated less postoperative discomfort, minimal invasiveness and less CBL. However, larger sample size is required to determine whether the ultrashort have an acceptable survival rate.

The Use of 4-mm Implants Splinted to 10-mm Implants for Replacement of Multiple Missing Teeth in the Posterior Maxilla Region with Expanded Maxillary Sinus. An Observational Cases Series: Patient Characteristics and Preliminary Results.

This study aimed to rehabilitate shortened maxillary dental arch with splinted crowns by connecting ultra-short implants with longer ones. In the posterior maxilla of 11 patients, one 10-mm (n = 11) and one or two ultra-short 4-mm (n = 17) dental implants were inserted. The insertion torque was lower than 20 Ncm in 55% of the 10-mm implants and in 94% of the 4-mm implants (P > .05). Median (range) implant stability quotients at the time of insertion and after 6 months were 61 (14 to 72) and 68 (51 to 79), respectively, for 4-mm implants, and 66 (52 to 78) and 78 (60 to 83), respectively, for 10-mm implants (P < .05). One 4-mm implant failed to integrate. All patients were restored with splinted metal-ceramic crowns connecting 4- and 10-mm implants. Median (range) clinical crown/implant ratios of 4-mm and 10-mm implants were 2.79 (1 to 3.66) and 1.06 (0.85 to 1.46), respectively (P < .05). Six months after prosthetic rehabilitation, the median (range) crestal bone loss was 0.3 mm (-0.7 to 1.7 mm) for 4-mm implants and was 0.5 mm (-0.8 to 3.5 mm) for 10-mm implants (P > .05). Splinted crowns combining 4- and 10-mm implants may contribute to a better force distribution in the treatment with ultra-short implant-supported prosthesis in the posterior maxilla.

Ultrashort Implants, Alternative Prosthetic Rehabilitation in Mandibular Atrophies in Fragile Subjects: A Retrospective Study.

This study aimed to evaluate the effectiveness of using ultrashort implants in the rehabilitation of jaws of fragile patients. The aim of the study was to retrospectively evaluate the survival rate of full-arch prosthetic rehabilitation on ultrashort implants, length 4 mm, 4 mm in diameter in the premolar and canine area and 4.5 mm in diameter in the molar area, with the insertion torque of 60 Nw and immediate loading. Nineteen patients were evaluated for 3 years clinically and radiographically. The significant majority of the patients at the 3 year follow-up (T4) presented a stable and functional implant-supported prothesis, and the survival rate of the implants was 85%, with a loss of 16 implants on 114 implants. The combination of the innovative implant surfaces and the correct project of the prostheses, with the related implant connection, determined a different timing in the therapy, allowing to obtain an immediate loading, which is currently demanded by patients. This and recent reports on short and ultrashort implant usage in atrophic jaws offer a good solution in critical cases. In conclusion, within the limits of the study, the full-arch rehabilitation with immediate loading on ultrashort implants showed good results with few postoperative complications and related low biological cost.

Analysis of micromovements and peri-implant stresses and strains around ultra-short implants - A three-dimensional finite-element method study.

Background:Success of an implant depends on its placement in the bone and how well the stress and strain are distributed to the surrounding structures when occlusal force is applied to it. The size and shape of the implant plays an important role is the formation and distribution of stress and strains in the periodontium. Von Mises stresses and micromovements need to be evaluated while placing implants in D4 bone quality regions for a higher success rate.Aim:To evaluate the peri-implant Von Mises stresses, strains, and micromovements distribution in D4 bone quality around ultra-short implants of 5 mm length with varying diameters of 4 mm, 5 mm, and 6 mm.Materials and Methods:The finite element method was employed to make models replacing maxillary molars in D4 type bone that was missing. Implants that could be classified as ultrashort (5 mm) were used. These implants were of varying diameters of 4, 5, and 6 mm. In each model, the implant was subjected to a force of 100 N and analyzed. The force was applied in an oblique (45 degrees) and vertical direction (90°) to the long axis of the tooth. The models were made such that they simulated cortical and cancellous anisotropic properties of the bone. The models were then analyzed using the program ANSYS workbench version 12.1.Results:When all the three diameters were compared wide diameter, i.e., 6 mm threads had the least values of peri-implant von Mises stresses, strains, and micro-movements around them. When thread shapes were taken into consideration square micro thread created the most favorable stress parameters around them with minimum values of stress, strains, and micromovements.Conclusion:Ultrashort implants combined with a wide diameter and platform switched can be used in atrophic ridges or when there is a need for extensive surgery to prepare the implant site.

Assessment of Peri-Implant Soft Tissues Conditions around Short and Ultra-Short Implant-Supported Single Crowns: A 3-Year Retrospective Study on Periodontally Healthy Patients and Patients with a History of Periodontal Disease.

The aim of this retrospective study was to evaluate implant survival, marginal bone loss and peri-implant complications in 326 short and ultra-short implants. Implants were placed in the maxillary and mandibular posterior regions of 140 patients with (PP) and without (NPP) a history of periodontal disease. Clinical and radiographic examinations were performed at 3-year recall appointments. The 8.0, 6.0 and 5.0 mm-length implants placed in PP and NPP were respectively 43.75% and 38.46%, 35.10% and 34.19%, 21.15% and 27.35%; 325 implants (one early failure) were rehabilitated with single crowns in 139 patients. Overall implant survival after 3 years of follow-up was 97.55%, 98.08% and 96.61% for PP and NPP (p = 0.46). Crestal bone level variations were not statistically different among PP and NPP; 15.41% of implants presented signs of mucositis, 14.71% and 16.67% in PP and NPP (p = 0.64). Setting the threshold for bone loss at 2 mm after 36 months, peri-implantitis prevalence was 2.2%, 1.96% and 2.63% in PP and NPP (p = 0.7). Overall implant success was 82.39%, 83.33% and 80.7% for PP and NPP (p = 0.55). Short-term outcomes suggest that short and ultra-short locking-taper implants can successfully be restored with single crowns in the posterior jaws both in PP and NPP.

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.