Multiple dental implant failures: A retrospective analysis of implant retention time and risk factors.

BACKGROUND: The present retrospective study investigates implant retention time in patients who had experienced multiple implant failures and explores possible risk factors. MATERIALS AND METHODS: Patients who underwent placement of at least two implants and experienced failure of two or more implants between 2004 and 2022 were included in the study population. Both patient- and implant-related risk factors, including age, sex, medical history, medication intake, smoking, alcohol consumption, implant properties and anatomical and surgical factors, were evaluated. Descriptive analysis and univariate and multivariate statistical analysis were performed to assess implant retention time and failure risk, with the level of statistical significance set at 0.05. RESULTS: A total of 371 patients (178 men and 193 women, median age 63 years) with 3,141 implants were included in the analysis (3.14% of all patients treated since 2004). Out of these implants, 1,090 failures were observed (59.01% of all failed implants at the Academy of Oral Implantology, Vienna, Austria), with a median retention time of 108.11 months. Patients who lost teeth due to periodontitis did not show a tendency towards early implant failure (P > 0.001). Nicotine consumption (P < 0.001), age < 50 years and > 70 years (P < 0.001), maxillary location (P = 0.05), transgingival healing (P < 0.001), no provisional restoration (P = 0.035) and short implant length (P < 0.001) were associated with statistically significantly shorter implant retention times. CONCLUSIONS: Patients with multiple implant failures displayed cluster behaviour and had a median implant retention time of 9 years. Smoking, short implant length, single-stage surgery and immediate loading were all associated with a higher risk of failure, whereas age between 50 and 70 years and tooth loss due to periodontitis were associated with a longer implant retention time.

Randomized controlled multi-centre study comparing shorter dental implants (6 mm) to longer dental implants (11-15 mm) in combination with sinus floor elevation procedures: 10-year data.

AIM: To compare implant survival and complication rates between shorter and standard-length implants with sinus augmentation and restored with single crowns, at 10 years of loading. MATERIALS AND METHODS: One-hundred and one patients (137 implants) with a ridge height of 5-7 mm in the posterior maxilla were randomly assigned to two treatment modalities: shorter implants (6 mm) (group short [GS]) or standard-length implants (11-15 mm) with sinus grafting (group graft [GG]). Following the insertion of final restorations, patients were regularly recalled for up to 10 years. Assessed outcomes encompassed implant survival, marginal bone levels (MBLs), biological and technical parameters and patient-reported outcome measures (OHIP-49 = Oral Health Impact Profile). Non-parametric statistical analysis was used to analyse the data. RESULTS: For the 5- to 10-year follow-up period, 77 patients with 105 implants (GS: 36 patients/48 implants; GG: 41/57) were available for re-examination (drop-out rate 21%). Implant survival rates at the patient level were 96.0% (GS; 2 failures) and 100% (GG) (inter-group p = .24). Median MBLs amounted to 0.00 mm (min 0.00; max 3.25; GS) and 0.00 mm (min 0.00; max 4.55; GG) (inter-group p = .73). Technical complications predominantly occurred within the first 5 years (inter-group p > .05). Peri-implantitis rates were 4.2% (GS) and 13.3% (GG) (intergroup p = .37). Median OHIP-49 scores were 7.00 (0.00; 39.00; GS) and 9.00 (0.00; 196; GG) (inter-group p = .61) at 10 years. CONCLUSIONS: Based on similar 10-year implant survival rates, reduced patient morbidity and lower costs, the use of shorter dental implants might well serve as an alternative treatment concept to longer implants placed in conjunction with sinus grafting for patients with a limited ridge height in the posterior maxilla. Study register: https://clinicaltrials.gov/ct2/show/NCT01030523.

Bucco-palatal implant position and its impact on soft tissue level in the maxillary esthetic zone.

AIM: The term "buccal implant position" is commonly used but lacks a precise definition and missing a reference point. Considering its major impact on peri-implantitis and esthetic failures the purpose of this study was to find a correlation between bucco-palatal implant positioning and the midfacial soft tissue level of implant crowns using newly defined Emergence-points. MATERIALS AND METHODS: Patients with unilateral single-tooth implant crowns in the region of the central or lateral maxillary incisor were included in this study. Digital intraoral scans were superimposed over a scan of the master cast or the original digital data set and analyzed in a computer planning program. In relation to the corresponding natural tooth, an ideal Emergence-point (EIDEAL -point) was defined from a frontal view. The distance to the real Emergence-point (EREAL -point) of the implant crown was correlated to apical displacement (AD) of peri-implant soft tissue. The distance of the implant shoulder (I-point) to the real Emergence-point (EREAL -point) of the implant crown was also correlated to the AD of peri-implant soft tissue. In cross sections, the horizontal distance between EREAL - and I-point represents the sagittal implant position (SIP), and the vertical distance represents the vertical implant position (VIP). RESULTS: Seventy-three patients met the inclusion criteria. AD ranged from 0 to 3.5 mm (AD = 0.87 ± 1.01), SIP from 0.2 to 5.1 mm (AD = 2.66 ± 1.64). Statistical analysis showed a significant inverse correlation between AD and SIP (ρ = -.55, p < .001). VIP, the implant inclination, time span since implant insertion, and phenotype revealed no significant correlation to AD. CONCLUSION: The more palatal the implant was positioned, the less AD was observed. The position of the implant shoulder should preferably be planned more than 2 mm behind the ideal E-point. This E-point can be used for implant planning as it defines the ideal crown length for prospective planning.

Esthetic Outcomes for Immediate Implant Placement with Immediate Provisionalization in the Anterior Maxilla with Buccal Dehiscence: Results of a Comparative Pilot Study.

PURPOSE: The aim of this pilot exploratory cohort study was to assess the value of buccal augmentation in immediate implant placement and immediate restoration of anterior teeth in maxillae with missing buccal lamellar bone with regard to esthetic parameters, as well as soft and hard tissue level changes. MATERIALS AND METHODS: This study compared three groups of 10 patients each with immediate implant placement and immediate restoration in the anterior maxilla: (1) patients with partially to totally missing buccal bone with simultaneous augmentation with bovine collagen (test group augmented [TGA]); (2) patients with partially to totally missing buccal bone without augmentation (test group nonaugmented [TNA]); and (3) patients with intact buccal lamellar bone (control group [CG]). The pink esthetic score (PES) and the course of the peri-implant bone level after 1, 3, and 12 months were used as assessment criteria. RESULTS: After 12 months, the PES in the TGA was assessed as being better than it was preoperatively (mean ± SD: 8 ± 3.09 vs 9.25 ± 3.01, respectively, P = .8243), while it remained almost identical in the other two groups (TNA = 8.75 ± 2.7 vs 8.6 ± 3.3, P = .4098; CG = 10.6 ± 2.41 vs 10.6 ± 2.22, P = .7085). A significant difference among the PES values of the three groups was not observed at any point in time (preoperative: P = .118, 12 months: P = .383). In total, the TNA and CG showed an improvement in 3 out of 7 parameters of the PES after 12 months, while this was the case in 5 out of 7 parameters in the TGA. No significant difference among the three groups could be seen at any time point regarding peri-implant bone level. In the CG and TGA patients, a nonsignificant improvement in peri-implant bone level was seen after 12 months (respectively: 1.6 mm to 0.99 mm; P = .08068; 1.89 mm to 1.73 mm; P = .5866). In contrast, TNA patients showed a nonsignificant deterioration vs the postoperative situation (1.16 mm to 1.45 mm; P = .08208). CONCLUSION: Within the limitations of this pilot study, it can be concluded that a missing buccal lamellar bone appears to be no contraindication for immediate implant placement and immediate restoration, provided the baseline esthetic situation is accepted. As compared to the nonaugmented defect group or the group with intact lamellar bone, neither the esthetic nor the radiologic results could be improved significantly by augmentation with bovine collagen.

Gingival recession behavior with immediate implant placement in the anterior maxilla with buccal dehiscence without additional augmentation-a pilot study.

BACKGROUND: Immediate implant placement in the presence of intact extraction alveoli has frequently been reported, while hardly any reports on immediate implant placement in missing buccal bone can be found in literature. OBJECTIVES: This pilot study evaluates esthetic outcome and soft and hard tissue level changes of immediate implant placement with immediate provisionalization in patients with partially/completely missing buccal bone without any further augmentation procedure in the maxillary anterior zone. MATERIAL AND METHODS: Twelve patients (TG) with partially to completely missing buccal bone designated for extraction and flapless immediate implant insertion in the anterior zone of the maxilla were included. Patients randomly selected out of a larger group of patients with immediate implants with intact alveoli served as controls (CG). Immediate provisionalization was done without any further augmentation of the alveolar ridge. Marginal hard and soft tissue levels, PES, and implant success were evaluated during a 1-year observation period. RESULTS: The defect of the buccal alveolar bone was 4.96 mm (min., 2.26 mm; max., 9.68 mm) and the mean mesio-distal extension 4.25 mm (min., 3.2 mm; max., 5.91 mm). Preoperative PES differed significantly between TG (9.68) and CG (12.25) and improved in TG postoperatively with no significant difference to CG after 1 year (TG, 10.91; CG, 11.3). The buccal soft tissue level remained almost unchanged over the observation period (TG preop, 0.86 mm ± 0.90 mm; 1 year, 0.91 mm ± 0.96 mm; CG preop, 0.98 mm ± 0.87 mm; 1 year, 0.98 mm ± 0.87 mm and did not show any correlation with either the mesial/distal bone level or the initial buccal vertical defect at any point of time. CONCLUSIONS: These clinical results provide evidence that immediate implant placement without additional augmentation, but with immediate provisionalization might be a viable treatment alternative even with missing buccal plate in the esthetic maxillary zone.

A description of the sequence of long-term behavior of autogenous boneblock in maxillary sinus augmentation in sheep: Additional morphologic and histomorphometric evidence.

OBJECTIVE: To document the behavior of autogenous bone block in sinus lift and surgical consequences. STUDY DESIGN: Twelve sinus lifts with autogenous hip bone blocks and simultaneous insertion of two implants in 6 adult female sheep. Polychrome sequential labelling and histologic and histomorphometric evaluation after 6, 16, and 26 weeks. RESULTS: Augmentation material in the apical third was almost fully resorbed after 26 weeks (P = .00388). Percentage of bone tissue increased 0.5-1.0 mm from the implant in crestal region (15.3 ± 7.5% to 16.2 ± 10.1%), whereas it vanished in the apical region from 16 to 26 weeks (4.2 ± 10.4% to 0%) (P = .363). CONCLUSIONS: Autogenous bone block leaves an apical thin but functionally crucial layer covering implants in a form follows function way. Denial of animal-originated biomaterials and prion diseases remain a rarely discussed issue. The use of an implant length-adapted autogenous transplant with osseoinductive advantages should be taken into consideration.

Alveolar Ridge Augmentation Using Dystopic Autogenous Tooth: 2-Year Results of an Open Prospective Study.

PURPOSE: To evaluate the use of chemically unchanged tooth material in lateral alveolar ridge augmentation or for the filling of jaw defects. MATERIALS AND METHODS: A total of 20 patients underwent either lateral augmentation of the alveolar process (11 patients) or filling of jaw defects (6 patients) with autogenous unaltered tooth material in a longitudinal 2-year study. In three patients, the jaw defect was so marked that a bone block graft had to be used for augmentation in addition to particulate dental material. In four patients, an autogenous tooth block was exclusively used; in seven, crushed tooth material was exclusively used; and in the remaining six, dystopic teeth that had been extracted were removed, crushed, and reinserted into the defect in particulate form. Fully impacted teeth served as autogenous donor teeth. RESULTS: After a healing time of 3 to 6 months, 28 implants could be placed (10 immediate implants, 18 delayed implants). At 6, 12, and 24 months postrestoration, peri-implant bone loss as assessed by x-ray was 0 mm, 0.4 mm, and 0.6 mm, respectively. Peri-implant probing depth was 1 mm after 1 year and 2 mm after 2 years. Bleeding on probing was not seen in any of the implants after 2 years. CONCLUSION: Autogenous tooth material appears to be suitable for the restoration of lateral and intraosseous defects of the alveolar ridge with both complete blocks and in particulate form. However, additional long-term studies with higher case numbers will be required for substantiating these results.

Short dental implants (6 mm) versus long dental implants (11-15 mm) in combination with sinus floor elevation procedures: 3-year results from a multicentre, randomized, controlled clinical trial.

AIM: To test whether the use of short dental implants (6 mm) results in an implant survival rate similar to that with longer implants (11-15 mm) in combination with sinus grafting. METHODS: This multicentre study enrolled 101 patients with partial edentulism in the posterior maxilla and a remaining bone height of 5-7 mm. Included patients were randomly assigned to receive short implants (6 mm; GS/group short) or long implants (11-15 mm) simultaneously with sinus grafting (GG/group graft). Six months after implant placement (IP), implants were loaded with single crowns (PR) and patients were re-examined yearly thereafter. Assessed outcomes included: implant survival, marginal bone level changes (MBL), probing pocket depth (PPD), bleeding on probing (BoP) and plaque accumulation (PCR) during 3 years of loading as well as recording of any adverse effects. In addition to descriptive statistics, statistical analysis has been performed for the two treatment modalities using a non-parametric approach. RESULTS: In 101 patients, 137 implants were placed. At the 3-year follow-up (FU-3), 94 patients with 129 implants were re-examined. The implant survival rate was 100% in both groups. MBL at FU-3 was 0.45 mm (GG) and 0.44 mm (GS) (p > 0.05). A statistically significant loss of MBL was observed in both GG (-0.43 ± 0.58 mm) and GS (-0.44 ± 0.56 mm) from IP to FU-3, and from PR to FU-3 in GG (-0.25 ± 0.58 mm) but not in GS (-0.1 ± 0.54 mm). PCR and BoP at FU-3 did not show any difference between the groups but for PPD (p = 0.035). CONCLUSIONS: Within the limitations of this study, implants with a length of 6 mm as well as longer implants in combination with a lateral sinus lift may be considered as a treatment option provided a residual ridge height of 5-7 mm in the atrophied posterior maxilla is present.

A New Method Using Autogenous Impacted Third Molars for Sinus Augmentation to Enhance Implant Treatment: Case Series with Preliminary Results of an Open, Prospective Longitudinal Study.

PURPOSE: This prospective longitudinal study reports on the results in patients given autologous tooth material for augmentation in a sinus elevation procedure. MATERIALS AND METHODS: Six patients with inadequate bone supply for augmentation in the maxillary posterior tooth region and at least one impacted maxillary third molar underwent sinus elevation surgery with lateral access using the particulate tooth material. One of the patients received four implants during the same session, while the other patients had a total of 15 implants placed after a healing phase of an average 5.5 months. Drill cylinders collected from the implant bed during the procedure were subjected to histologic/immunohistochemical evaluation. RESULTS: All six patients showed normal and unobtrusive postoperative healing, having undergone prosthetic restoration up to 5 years before. The average peri-implant probing pocket depth after a period of up to 5 years ranged between 1.86 mm (mesial and lingual) and 2.07 mm (distal and buccal). No bleeding could be triggered with any of the peri-implant probes. The average peri-implant bone resorption measured during the first year was up to 0.63 mm, with the lowest being 0 mm and the maximum 2.9 mm. Peri-implant bone remained stable for the follow-up time of up to 5 years. Histologically, six biopsy specimens collected from five patients showed osteoconductive osteogenesis with encapsulation of tooth enamel and dentin portions and partial resorption of the tooth components. Cementum shares were no longer discernible. Immunohistochemical assessment showed intense new vessel formation that could be observed in the area of loose stroma of reorganized tissue in the augmented area. CONCLUSION: Within the limits of these preliminary results and with adequate consideration of the small number of patients included, the use of autogenous crushed tooth material from impacted third molars may represent an alternative augmentation material for use in sinus elevation procedures.