Use Of Short Implants Research Articles

Characteristics and impacts of dental implant displacement into the maxillary sinus

Background/purposeDental implants displaced into the maxillary sinus are considered to require surgical removal as the treatment of choice. However, displaced implants have been reported to affect the maxillary sinus in different ways. This study aimed to evaluate characteristics and impacts of dental implant displacement into the maxillary sinus. Materials and methodsFourteen sinuses with displaced implants into the maxillary sinus were included. Demographic data and radiographic images were analyzed, with a focus on the impact of various factors such as demographic data, timing of displacement, duration of retention, and residual bone height on maxillary sinus opacification and sinus wall thickness. ResultsImplants were displaced during or in the early stage after implant placement in 9 cases and after functional loading in 5 cases. Radiographic evaluations showed higher sinus opacification score (P = 0.019) and increased wall thickness (P = 0.198) in cases with displacement after functional loading, although the difference in wall thickness was not statistically significant. When the duration of implant retention in the sinus was longer, higher sinus opacification and sinus wall thickness were observed, although the differences were not statistically significant. Univariate regression analysis demonstrated that the timing of displacement significantly influenced maxillary sinus opacification (P = 0.013) and sinus wall thickness (P = 0.013). For all cases, evidence of site preparation and the use of short implants were not observed. ConclusionThis study suggests that adequate pre-implant site preparation and timely intervention are essential to prevent and manage implant displacement into the maxillary sinus.

Clinical outcomes of short dental implants supporting prostheses in the posterior region.

Aim In clinically challenging scenarios with limited bone height and anatomical restrictions, the use of short implants have been proposed as a potential treatment strategy. The purpose of this retrospective study was to evaluate the clinical outcomes of short implants supporting prostheses in the posterior premolar region of the maxilla and mandible.Materials and methods A total of 30 patients requiring short 6 mm length implant placement in the posterior premolar region were included. Following a period of osseointegration, the implants were restored with either single crowns, fixed bridges or implant-supported removable overdentures. Implant and prosthetic survival with technical complications were recorded.Results In total, 45 implants were placed, with four failures reported before loading in two patients, resulting in a patient implant survival rate of 93.3% over the two-year follow-up. There was no statistically significant difference found between implant failure and arch placement. Prosthetic survival was 100% and minor technical complications recorded were low.Conclusion This study showed that short 6 mm implants could provide a viable treatment option, with high survival rates comparable with alternative bone augmentation procedures. Further research with longer observation periods would be required to validate these current findings.

Evaluation of two treatment concepts of four implants supporting fixed prosthesis in an atrophic maxilla: finite element analysis

BackgroundCurrently, oblique placement of long implants or the use of short implants to circumvent the maxillary sinus area and provide support for fixed prostheses are viable alternatives. The purpose of this study was to compare these two treatment concepts and ascertain which one exhibits superior biomechanical characteristics.MethodsTwo different treatment concept models were constructed. The first one, LT4I, consisting of two mesial vertical implants positioned in lateral incisor regions and two distal tilted implants (45°) situated in second premolar regions of the maxilla. The second model, VS4I, includes two mesial vertical implants in lateral incisor regions and two vertically positioned short implants in second premolar regions. Numerical simulations were conducted under three loading types: firstly, oblique forces upon the molars; secondly, vertical forces upon the molars; thirdly, oblique forces upon the incisors. The maximum principal stress (σmax) and minimum principal stress (σmin) of the bone, as well as von Mises stress of the implants, were calcuated.ResultsUnder oblique loading on the molar, higher stress values in the bone were observed in LT4I group. Under vertical loading on molar, higher stress values in the bone were also observed in LT4I group. Furthermore, little difference was found between the two groups under oblique loading on the incisor.ConclusionBoth treatment concepts can be applicable for edentulous individuals with moderate atrophic maxilla. Compared to tilted implants, short implants can transmit less occlusal force to the supporting tissues.

FEA on the biomechanical behavior of immediately loaded implants with different sizes

Objectives. The purpose of this research was to study, in the case of immediate loading, the biomechanical effect produced by the length of the implants. Material and method. The study material was a CBCT analysis performed on a patient from one dental office in Bucharest. An segment of edentulous mandibular bone was selected from the CBCT, which was processed with Mimics Innovation Suite, respectively Mimics and 3-matic. After processing the bone segment, two implants of the same manufacturer, with identical design, but different length – 10 and 13 mm respectively, were selected from the BIOMAT database. To simulate immediate loading, the bone-implant interface was not blocked and the mandible was defined with properties that characterize a bone with moderate density. A perpendicular masticatory force of 200N was applied to each of the two implants. The software ANSYS calculated the minimum, maximum values and their geometric means for the possible stresses produced on both the shorter implant (10 mm) and the longer implant (13 mm). Results. In the case of short implants, higher average stresses develop along the entire length of the implant, towards the vestibular bone plate, while in the case of long implants the higher stress seems to be cantoned towards the apical side. Conclusions. The present study shows that, in the case of immediate loading, the use of longer implants (13 mm) reduces by more than 50% the geometric mean of the stresses to which the bone-implant interface is subjected than in the case of the use of shorter implants (10 mm). In both types of implants, higher stresses occur at the level of the screw fixing the abutment in the implant.

A Study Case of Short Dental Implants Loading in the All-On-4® System on Fixed Dental Prostheses: A Finite Element Analysis

The biomechanical research about toothless mandible with four dental implants and a prosthetic system research, which shows the influence of the cantilever length of prosthesis on the weakest structural elements and the load changes in peri-implant bone by changing symmetrically position of the dental implants (in relation to each other), diameters and lengths, and orientation (in relation to chewing surfaces), is not discussed widely in the scientific literature. On the other hand, the use of short implants is more common in practice. Some of these implants are only 8mm in length.The odontologists, implantologists and dental technician can use results received by finite element method (FEM) in the daily clinical practice in order to reduce the potential for mechanical / technological and consequent biological complications already at the planning stage of the treatment, and thus determine best outcomes in the treatment of toothless patients.With a unique interpretation of the results obtained by FEM, the paper discusses the results of implants (8 mm in length with 3.5 mm and 4.5 mm diameter) loading, when the cantilevered dental prostheses are loaded in different positions, as well as implant positions are changed.

Ретроспективна оцінка дефіциту доступної кістки у пацієнтів в Україні за даними застосування дентальних імплантатів різних розмірів

The purpose of the study was to determine a number of clinical cases of dental implantation with insuficient height of the alveolar ridge based on data of consumption of the dental implants of various designs in dental healthcare institutions during 10 years. Materials and methods. The research was performed on the provided information on the sales of dental implants produced by the DENTIUM corporation, “SuperLine” and “SuperLine NEW” (Korea) from the official supplier in Ukraine (“Stamil” group of companies) for the period 2013–2022. Results and discussion. Quality and sufficient volume of bone tissue around the dental implant is an important condition to achieve an optimal level of osseointegration. In cases of a shortage of available bone an additional option in the choice of treatment tactics is the installation of short dental implants. Compared with dental implants of standard and extended length the short implants showed a higher frequency of rejection and early disintegration. The length of the dental implant body is a critical factor in the long-term successful functioning of implants which is ambiguously evaluated and described in the professional literature. The analysis in the subgroups of the use of short implants showed that in the vast majority of cases, dental implants with a length of 8.00 mm were used – in the volume of ten-year implementation, their specific weight was 24.92%. Accordingly, it can be assumed that the volume of application of such structures is identical to the specific gravity of cases of minimal deficit in the height of the bone tissue of the alveolar crest of the jaws – 2.00 mm. The use of descriptive statistics methods made it possible to calculate the average percentage of such clinical cases – 23.92 ± 5.71 mm (M=25.37 mm). In calculations per decade the specific weight of cases of the alveolar ridge height deficiency of the jaws (lack of available bone tissue) was 30.03%. The average value was 28.80 ± 6.74% (M=30.95%), the minimum – 19.11% and the maximum – 38.08%. There were only 1.42% cases of “compensation” of the short implant length by increasing its diameter (upto 6.00 and 7.00 mm) in the overall structure of the performed operations. The usage of average annual number of short dental implants of increased diameter (from 6.00 mm) was 0.67 ± 0.28% (M=0.56%). The analysis of dynamics of the usage of short dental implants (7.00 mm and 8.00 mm) over ten years period revealed unevenness. For implants with a length of 8.00 mm frequency varied between 15.00–30.00%. The usage of shorter structures (length 7.00 mm) did not have such critical changes – minor deviations near 5.00%. Conclusion. The obtained results allowed to determine indirectly the prevalence of the alveolar ridge height deficiency in patients of “implantation cohort” in Ukraine during the last 10 years

Biomechanical analysis of different fixed dental restorations on short implants: a finite element study.

Although the use of short implants is becoming more common for patients with atrophic alveolar ridges, their use is still quite limited. This is due to the lack of data of long-term survival compared to standard-length implants. The aim of this study was to determine the load in the bone and implant system with different superstructures. Three kinds of prosthetic restorations were created on short implants based on CT-Data. Two short implants with different macro-geometries were used. The implants were inserted in idealised posterior lower mandibular segments and afterwards restored with a crown, a double splinted crown, and a bridge. The analysis was performed under load of 300 N either divided between a mesial and distal point or as a point load on the pontic/mesial crown. The different design of the implant systems had a noticeable influence on the stress in the cortical bone, in the implant system, and the displacement of the superstructure as well. Compared with implants of standard length, higher stresses were observed, which can lead early failure of the implant during the healing period or a late cervical bone resorption. Precise indications are essential for short implants to avoid the failure of short implants.

Single-Unit Short Implants in the Molar Region: A Retrospective Study with a Minimum 3-Year Follow-up.

The high biomechanical loads in molar region wounds challenge the indication for short implants to be used as a single-unit implant. This study reports on the outcomes of single-unit short implants (≤ 8.0 mm) in the maxillary and mandibular molar regions. Forty-nine short implants were placed in 48 patients to replace a missing molar tooth. Two-piece restorations with screw retention were fabricated. During the follow-up, implant survival and marginal bone loss (MBL) were assessed. The known implant length was used as a reference to calibrate the linear measurements on digital periapical radiographs, and descriptive statistical analysis was performed. The implants were followed over a period of 47 ± 12 months. No implant failure was recorded, and no prosthesis failure was observed. The average MBL was 0.15 ± 0.5 mm. The mean crown height space was 13 ± 3 mm. The overall crown-to-implant ratio was 1.7 ± 0.4. Two technical complications occurred due to the loosening of the unit abutment. After screw re-tightening, no more screw loosening was observed. This study supports the use of short implants as a single-unit implant in the maxillary and mandibular molar regions.

Evaluation of the survival rate of short implants placed in the posterior atrophic mandible: 5-year clinical study.

The aim of the study was to assess the long-term prognosis of short implants (5 to 6 mm) placed in the posterior region of the atrophic mandible. The study included 81 patients with severe vertical atrophy of the bone in the posterior region. The patients had 248 short implants (5 to 6 mm) implants placed in the mandibular posterior region and 256 implants with length greater than 10 mm in the mandibular anterior region. Analysis of implant and prosthesis failures, cumulative survival rate, and marginal bone loss was determined at 1 year and 5 years of follow-up (58 ± 7 months). Mean marginal bone loss after 1 year of prosthetic loading was 0.74 mm for short implants and 0.72 mm for implants with length greater than 10 mm; after 5 years of prosthetic loading this was 1.27 mm for short implants and 1.31 mm for implants with length greater than 10 mm. Of 248 short implants (5 to 6 mm), six failed: four due to peri-implantitis and two due to lack of osseointegration (early rejection). Of 256 implants with length greater than 10 mm, five failed: three due to peri-implantitis and two due to lack of osseointegration (early rejection). On average, over the observation period (58 ± 7 months), the 5-year cumulative implant survival rate was 97.8% in short implants, and 98.1% in longer implants; the prosthesis cumulative survival rate was 98.2%. Based on the results, it was concluded that the prognosis of the use of short implants for prosthetics in the posterior resorbed mandible can be considered favorable and reasonable.

SHORT IMPLANTS IN POSTERIOR JAWS– A LITERATURE REVIEW

One of the greatest challenges that dentists face today is to rehabilitate severe atrophied alveolar ridges in partially and completely edentulous patients with implants. Loss of bone volume at the level of the posterior maxilla and mandible can complicate rehabilitation with implants, since it leads to a reduction in the distance to the maxillary sinus and the inferior alveolar nerve, respectively. Various techniques have been used for many years to avoid damaging these structures, such as alveolar ridge augmentation procedures, bone grafting, tooth nerve transposition, or even zygomatic implants. An alternative to these surgical treatments is the use of short implants in areas where bone availability is reduced.

Major clinical findings of short implants and virtual surgery: a systematic review

Introduction: After the confirmation and publication of the phenomenon known as osseointegration by Brånemark, dental implants have been used to repair total and partial edentulous jaws. However, the implants were long and had to be longer than 11 mm to be considered functional. Short implants compared to long ones require less remaining bone, reducing the patient's exposure to surgeries for bone grafting, the elevation of the maxillary sinus mucosa, and repositioning of the inferior alveolar nerve. Added to this, several dental treatments have benefited from this digital advance. Objective: To review the literature on short implants installed in both dental arches, evaluating their advantages, disadvantages, indications, and contraindications in the context of virtual surgery. Methods: The present study followed a systematic review model (PRISMA). The search strategy was performed in the PubMed, Scielo, Cochrane Library, Web of Science and Scopus, and Google Scholar databases. Results: A total of 110 articles were found, 64 articles were evaluated and 35 were rejected for not meeting the GRADE classification, and only 29 articles were used in this study to compose the textual part. Based on these findings, it was found that in remote years, authors reported that regions with reduced bone height are favored with the use of short implants not only because of their dimensions but also because of their surface treatment, which suggests that it is an important factor for achieving 100% success rates. The advantages of short implants are related to the simplicity of the technique, installation of implants in remaining bone, avoidance of bone grafts that present questionable results in the increases in height of the posterior alveolar ridge of the mandible, reduction of treatment time, and reduction of costs for the patient. A systematic review and meta-analysis studies analyzed the accuracy of implant placement using computer-guided surgery. A randomized study compared the precision of guided planning of new computer-assisted implant placement techniques, based on models that use CAD/CAM. Conclusion: It was concluded that short implants are a reliable, safe, and practical alternative to be used in any necessary location or situation. They do not show bone loss or resorption over the years, nor are they at risk of fracture or any damage to patients. They are safe to use, as long as they have an adequate design, therefore, fundamental tools in the dental clinic.

Bone quality effect on short implants in the edentulous mandible: a finite element study

IntroductionThe aim of this study was to verify whether the use of short implants could optimize stress distribution of bone surrounding implants in atrophic mandibles with different bone qualities.MethodsA three-dimensional model of the atrophic mandible with three levels of bone quality was made using computer software. Short implants (6 mm) and standard implants (10 mm) were used in four designs: Design 1 "All-On four", Design 2 "All-On-four" with two short implants, Design 3 four vertical implants with two short implants, and Design 4 six short implants. The distal short implants were placed at the first molar position. All twelve models were imported into finite element analysis software, and 110 N oblique force was loaded on the left second premolar. Maximum principal stress values of peri-implant bone and the volumes of bone with over 3000 microstrians (overload)were analyzed.ResultStress values and volumes of overload bone increased in all four groups with the decline of bone quality. The highest stress values were found in the cortical bone surrounding the Design 1 inclined implant in two lower bone quality mandibles, and the lowest in Design 3. However, Design 1 had less overload bone tissue than all three designs with short implants.ConclusionShort implants placed posteriorly helped decrease stress values in peri-implant bone, while bone surrounding short implants had a high resorption risk in low bone quality mandible.

Short versus Longer Implants in Sites without the Need for Bone Augmentation: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Objectives: The present systematic review and meta-analysis aims to analyse the clinical performance of short compared to longer implants inserted in sites without the need for bone augmentation. Methods: The protocol of the present PRISMA-driven meta-analysis was registered on PROSPERO (CRD42021264781). Electronic and manual searches were performed up to January 2022. All Randomized Controlled Trials (RCTs) comparing short (≤6 mm) to longer (≥8.5 mm) implants placed in non-atrophic and non-augmented sites were included. The quality of the included studies was assessed using the Cochrane risk of bias tool for randomized clinical trials (RoB 2) and the quality of evidence was determined with the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. A meta-analysis was performed on implant survival rate, marginal bone level change (MBLc), and technical and biological complications at the available follow-up time points. The power of the meta-analytic findings was determined by trial sequential analysis (TSA). Results: From 1485 initial records, 13 articles were finally included. No significant difference was found in the survival rate between short and long implant at any follow-up (moderate quality of evidence). Significantly more bone loss for long implants at 1 and 5 years from implant placement and more technical complications with short implants at 10 years were found. No other significant inter-group differences in terms of MBLc and biological complications were detected. Conclusions: Moderate evidence exists suggesting that short implants perform as well as longer ones in the rehabilitation of edentulous sites without the need for bone augmentation. Further long-term, well-designed RCTs, however, are still needed to provide specific evidence-based clinical recommendations for an extended use of short implants in non-atrophic sites.

Success rate of short unitary implants installed in atrophic mandible: Integrative Review.

In the rehabilitation of total edentulous patients, lack of bone availability in posterior maxillary regions is common due to pneumatization of the maxillary sinus and posterior mandible due to the presence of the lower alveolar nerve. And to rehabilitate this type of patient, one of them is the use of short implants. The work aims to evaluate the success rate of treatment of short implants through a literature review. The search was carried out in august 2020 in the Pubmed (MedLine), Scopus and Embase databases, using the keywords: extra short implants, short implants, survival rate, single implant, atrophic mandible. The keywords followed the AND or OR criteria previously elaborated by the PICO question. The inclu-sion criteria were: implants with a length of 4 to 8 mm, which were single and in the posterior region of atrophic mandible and which had 5 years of follow-up. Articles were excluded from the review where the implants were splinted, had a follow-up of less than 5 years and considered short implants larger than 8 mm. After the search, 4 articles were separated, which totaled an n = 172 short implants obtaining a success rate of 93.47% in 5 years. After the search, 4 articles were separated, which totaled an n = 172 short implants obtaining a success rate of 93.47% in 5 years. We can conclude that the use of short implants, even in single prostheses, has a high success rate, which can provide the edentulous patient with little bone bioavailability for rehabilitation.

Effect of crown-to-implant ratio and crown height space on marginal bone stress: a finite element analysis

BackgroundCrown-to-implant ratio and crown height space, associated with the use of short implants, have been related with marginal bone loss. However, it is unclear which of the two entities would play the most important role on the bone remodelling process. Using a finite element analysis, the present work aims to help clarifying how those two factors contribute for the stress generation at the marginal bone level. A numerical model (reference model), with a crown-to-implant ratio of 4, was double validated and submitted to a numerical calculation. Then, it was modified in two different ways: (a) by decreasing the prosthetic height obtaining crown-to-implant ratios of 3, 2.5 and 2 and (b) by increasing the implants length obtaining a crown-to-implant ratio of 2.08. The new models were also submitted to numerical calculations.ResultsThe reference model showed a marginal bone stress of 96.9 MPa. The increase in the implants’ length did not show statistically significant differences in the marginal bone stress (p-value = 0.2364). The decrease in the prosthetic height was accompanied with a statistically significant decrease in the marginal bone stresses (p-value = 2.2e− 16).ConclusionsThe results represent a paradigm change as the crown height space appears to be more responsible for marginal bone stress than the high crown-to-implant ratios or the implants’ length. New prosthetic designs should be attempted to decrease the stress generated at the marginal bone level.

An evaluation of peri-implant marginal bone loss according to implant type, surgical technique and prosthetic rehabilitation: a retrospective multicentre and cross-sectional cohort study.

To evaluate implant loss (IL) and marginal bone loss (MBL); follow-up period of up to 10years after prosthetic loading. Retrospective multi-centre cross-sectional cohort study. Double analysis: (1) all the implants (n = 456) were analysed; (2) to allow for possible cluster error, one implant per patient (n = 143) was selected randomly. Statistical analysis: Spearman's correlation coefficient; Kruskal-Wallis (post-hoc U-Mann-Whitney); Chi-square (post-hoc Haberman). (1) Analysing all the implants (456): IL was observed in patients with past periodontitis (6 vs. 2.2%, p < 0.05), short implants (12 vs. 2.8%, p < 0.001) and when using regenerative surgery (11.3 vs. 2.9%, p < 0.001); greater MBL was observed among smokers (0.39 ± 0.52 vs. 0.2 ± 0.29, p < 0.01), maxillary implants (0.28 ± 0.37 vs. 0.1 ± 0.17, p < 0.0001), anterior region implants (0.32 ± 0.36 vs. 0.21 ± 0.33, p < 0.001), external connection implants (0.2 ± 0.29 vs. 0.63 ± 0.59, p < 0.0001), and 2-3years after loading (p < 0.0001). (2) analysing the cluster (143): IL was observed in smokers (18.8 vs. 3.5%, p < 0.05), splinted fixed crowns (12.9%, p < 0.01), short implants (22.2 vs. 4.0%, p < 0.01) and when using regenerative surgery (19.2 vs. 3.4%, p < 0.01); greater MBL was observed in maxillary implants (0.25 ± 0.35 vs. 0.11 ± 0.18, p < 0.05), in the anterior region (p < 0.05), in the first 3years (p < 0.01), in external connection implants (0.72 ± 0.71 vs. 0.19 ± 0.26, p < 0.01) and in short implants (0.38 ± 0.31 vs. 0.2 ± 0.32, p < 0.05). There is greater risk in smokers, patients with past periodontal disease, external connection implants, the use of short implants and when regenerative techniques are used. To prevent MBL and IL, implantologists should be very meticulous in indicating implants in patients affected by these host factors.

Frequency of Bone Augmentation Materials Use in a General Dental Practice.

This retrospective study aimed to evaluate the frequency of bone augmentation materials used for implant or periodontal surgical treatment depending on the age and sex of the patients from a dental practice in Essen, Germany, but also the implants dimensions and respectively the stage and progression grade of the periodontitis. The analysis of the data showed that bone augmentation materials are used much more frequently in the implant surgical cases (43,33%) compared to periodontal surgical cases (13,33%). While the correlations with sex and age were less obvious, the use of bone augmentation materials in the implant surgical cases was correlated with the use of shorter implants, while their use in the periodontal surgical cases was correlated with the stage 3 periodontitis.

Short Implants in Posterior Mandible: Case Report

Numerous studies show that after the insertion and osseointegration of the implants, only the first 2-3 spires assure their functioning. As a consequence, the minimum length of the implants diminished, and therefore the use of short implants is more and more frequent. Together with the shortening of the length of the implants, the apex was also changed to increase the surface of the implants and as a result their stability, as well as to avoid the injuring of the critical anatomical structures (sinus membrane, inferior alveolar nerve). This paper presents a case report in which implants in the posterior mandible 5.5 mm long and 5 mm in diameter were used. Drilling in the proximity of the mandibular canal was made with front cutting drills and for the stimulation of the osseous apposition in the newly created orifice and on the surface of the implant Plasma Rich in Growth Factors (PRGF) was applied. The implants were prosthetized by applying for ceramic dental work on zircon fastened by cementation. The literature of the field shows that a 2:1 crown–implant proportion does not determine osseous resorption but a higher crown of 16 mm generates long term osseous resorption. As a conclusion, we can state that short implants are a very good alternative to more complex surgical techniques like the insertion of the implants next to the inferior alveolar nerve, the lateralization of the inferior alveolar nerve or the vertical osseous augmentation.

Сравнительная оценка эффективности дентальной имплантации у пациентов с атрофией костей челюсти с короткими и более длинными имплантатами

The aim of this study is to compare the survival rate of dental implants with short implants (&lt; 8 mm) and longer implants ( 8 mm) in patients with atrophy of the jaw bones. Materials and research methods. This study is based on the analysis of treatment outcomes in 107 patients, 59 of whom received short implants (&lt; 8 mm) and 48 patients received implants ( 8 mm) using a combination of augmentation. The study determined the engraftment of 5–6 mm Bicon implants and compared it with that of other implant sizes: Results. The average loss of marginal bone after one year was 0.96±0.25 mm for short implants and 0.94±0.46 for long implants. The survival rate of short implants (6–8 mm) after 3 years was 97.8 %, the survival rate of long (10–13 mm) implants was 98.1 %. The patients were satisfied with the aesthetic and functional result of the treatment. The results showed that implantation using short ones is effective in improving the chewing ability of patients in patients with atrophy of the jaw bones. In difficult clinical conditions, with a pronounced bone tissue deficiency, the use of short implants is the most gentle surgical method for restoring the missing support of fixed prostheses. Key words: atrophy of the jaw bones, dental implantation, short implants.

Survival Rates of 8-mm or Shorter Tissue-Level Implants in Function for Up to 228 Months.

Advances in surface technology and the understanding of the capabilities of osseointegrating implants have led to the use of shorter implants in a variety of clinical situations. Such implant use offers a number of potential advantages in the posterior maxilla and mandible. The purpose of this retrospective study was to examine the success rates of shorter, tissue-level implants in function for at least 60 months. A retrospective study was conducted of all patients treated between January 1, 1998, and December 31, 2012, who received tissue-level endosseous implants 8 mm or less in length, which were restored with abutments and single crowns. Patient age, sex, location of implants, and diameter of implants were examined. Time in function and stability of peri-implant crestal bone were assessed. The retrospective analysis identified 4,251 tissue-level implants that were restored with single abutments and crowns. These implants were followed for up to 228 months in function, with a mean time in function of 127.2 months. Implant success was assessed using commonly utilized metrics combined with bone sounding on the midbuccal and midlingual/palatal aspects of the implants. The cumulative success rate was 99.5% for all implants. In the posterior mandible, the success rate for regular-neck implants was 99.3% (n = 680, mean time in function: 136.5 months) and was 99.7% for wideneck implants (n = 2,320, mean time in function: 124.5 months). In the posterior maxilla, the success rate for regular-neck implants was 97.8% (n = 211, mean time in function: 169.1 months), and for wide-neck implants, it was 99.2% (n = 1,040, mean time in function: 127.8 months). The use of shorter (8 mm or less in length) tissue-level implants in the maxilla and mandible, restored with single abutments and crowns, offers a viable treatment option, assuming specific criteria and protocols are followed. These criteria and protocols are discussed.