TL;DR
Ten-year cumulative survival rate for implants placed in the grafted sinuses was 90.1%.
Within the limitations of this study, dental implants placed after interpositional sandwich grafting showed higher long-term survival and less MBL than implants placed after onlay grafting in the atrophic mandible.
BACKGROUND Systemic alterations are highly prevalent in the population and may interfere with peri-implant repair. PURPOSE The aim of this study was to investigate the association between systemic conditions with the loss of dental implants. MATERIALS AND METHODS This is a retrospective study following STROBE guidelines, including data from 602 medical records of patients who received dental implants between 2000 and 2017. Data on healthy status (presence or absence of disease or systemic conditions), use of prescribed medications (yes/no, and type), number of implants placed and lost, type of prosthetic rehabilitation, and follow-up period were collected, along with demographic data and local risk factor. Fisher's exact test assessed the association between systemic conditions and implant loss. Implant survival was analyzed using Kaplan-Meier and compared by the log-rank test (Mantel-cox). Binary logistic regression estimated odds ratios and confidence intervals for factors associated with implant loss. RESULTS A total of 1872 dental implants were placed, including 743 in healthy patients (success rate: 96.76%) and 1129 in systemically compromised patients (success rate: 97.60%), with no significant difference between groups (p = 0.1405). Kaplan-Meier analysis demonstrated similar implant survival rates between healthy and systemically compromised patients over a follow-up of 11 years (132 months, 93.84% and 94.92%, respectively). The curves showed substantial overlap, and no difference was observed (log-rank, p = 0.1566). The loss of implants was not associated with the presence of systemic condition or local factors (p > 0.05). Binary logistic regression analysis identified predictors of implant loss, with the model explaining 5.24% of the variance (R2 = 0.0524). A higher frequency of implant loss was observed in patients over 50 years of age, regardless of systemic status. CONCLUSION According to the methodology of this study, no association was observed between systemic conditions and dental implant loss.
This retrospective cohort study aimed to explore the relationships between patient characteristics and surgical techniques and radiographic marginal bone loss (MBL) and postoperative complications in individuals receiving dental implants. Electronic medical records (EMR) of adults (age ≥ 18 years) who received at least one dental implant between January 2015 and October 2023 and underwent radiographic evaluation at least 6 months after prosthesis insertion were reviewed. Patient-level variables included demographic, systemic, behavioral, and oral-hygiene characteristics, whereas implant-level variables included implant type, location, and grafting status. Analyses were primarily conducted at the implant level. The oral-hygiene status was retrospectively categorized based on EMR data. MBL was recorded dichotomously based on radiographic evidence of implant thread exposure. Descriptive statistics and exploratory bivariate analyses were performed using chi-square and Fisher’s exact tests, respectively. This study included 218 implants from 109 patients. Most implants were bone-level and placed in the native bone. Grafting was more frequently performed at caries-related sites and in patients with good oral hygiene. Older age was associated with poorer oral hygiene, whereas the education level and smoking status were not significantly associated with the oral-hygiene status. Radiographic MBL and postoperative complications were infrequent. Grafting status was not significantly associated with radiographic MBL. Within the limitations of this retrospective cohort study, good oral hygiene and surgical techniques were associated with favorable short-to-mid-term outcomes of implant treatment. Prospective studies with standardized follow-ups and calibrated radiographic assessments are required to clarify these relationships.
AIM To assess the survival rates of dental implants placed in previously failed sites and identify systemic, site-specific and implant-related factors associated with implant loss. METHODS This study included all dental implants (177,410 implants in 59,238 patients) placed between 2014 and 2023 within a nationwide dental network. Implant sequence (first, second, third or subsequent placement at the same site) was identified. Implant survival was assessed using Kaplan-Meier analysis and log-rank test. The Andersen-Gill extension of the Cox proportional hazards model was used in a multivariable analysis to identify independent predictors of failure. Separate Andersen-Gill Cox models were fitted for early and late failures. RESULTS Overall implant survival was 97.5% after a mean follow-up of 4.61 ± 2.72 years. Survival declined progressively with repeated placement, from 97.6% (169,990/174,187) for first implants to 92.2% (2748/2980) for second implants and 88.5% (215/243) for third or subsequent implants (p < 0.001). The hazard of failure was 4.6 times higher for second implants (HR 4.60; 95% CI, 3.98-5.32; p < 0.001) and 5.7 times higher for third or later implants (HR 5.71; 95% CI, 3.68-8.87; p < 0.001), compared to the first implants. Independent predictors of failure included smoking, male sex, penicillin allergy, narrow diameter and maxillary placement. The association between implant sequence and failure differed by time after implantation. The hazard of early failure was 6.80 times higher for second implants (95% CI, 5.78-8.00; p < 0.001) and 9.27 times higher for third or later implants (95% CI, 5.57-15.45; p < 0.001), compared to the first implants. The hazard of late failure was 1.93 times higher for second implants (HR 1.93; 95% CI, 1.40-2.65; p < 0.001) and 2.63 times higher for third or later implants (HR 2.63; 95% CI, 1.24-5.58; p = 0.011), compared to the first implants. CONCLUSION Reimplantation showed relatively favourable survival; however, failure risk increased with each successive implant placed at the same site, particularly early failures. Additionally, smoking, male sex, penicillin allergy, short and narrow implants and maxillary location were independent predictors of failure.
BACKGROUND This study aimed to determine the independent influence of bone quality and prosthetic material on medium-term implant survival, peri-implant complications, prosthetic complications, and patient-reported outcomes following All-on-4 rehabilitation. METHODS This retrospective, observational, multicenter cohort study included 250 edentulous patients (125 maxillary and 125 mandibular cases) who received All-on-4 implant-supported full-arch prostheses between September 2018 and September 2021. Patients were categorized by bone type (Types 1-4) according to the Lekholm and Zarb classification. Clinical parameters, insertion torque, implant stability quotient (ISQ), peri-implant and prosthetic complications, and patient satisfaction (VAS score) were recorded and analyzed. Prosthetic materials used were either metal-acrylic or monolithic zirconia prostheses. RESULTS A total of 1,000 implants were evaluated over a mean follow-up period of 3.6 ± 0.4 years. The overall implant survival rate was 94.8%, with significantly lower survival in Type 4 bone (89.1%) compared to Type 1 (98.3%) (p < 0.05). Peri-implant complications, particularly peri-implantitis and screw loosening, were significantly more frequent in lower-density bone types. Prosthetic complications were analyzed at the prosthesis level and were more frequent in the metal-acrylic group (26.9%) than in the zirconia group (8.9%) (p < 0.001). Despite these differences, patient satisfaction scores were high across all bone types (Mean VAS: 8.7 ± 1.2). CONCLUSIONS The All-on-4 concept demonstrated predictable medium-term clinical outcomes, with high implant survival and favorable patient satisfaction in completely edentulous patients. However, poorer bone quality, particularly Type 4 bone, was independently associated with lower implant survival, reduced primary stability, and a higher frequency of peri-implant complications. In addition, monolithic zirconia prostheses were associated with fewer mechanical complications than metal-acrylic prostheses. These findings highlight the importance of individualized treatment planning that integrates bone quality assessment and prosthetic material selection to optimize medium-term clinical outcomes. Although the findings should be interpreted in light of the retrospective observational design and medium-term follow-up, they provide clinically relevant evidence to support risk-informed clinical decision-making in full-arch implant rehabilitation.
Rehabilitation of the severely atrophic maxillae remains one of the most demanding challenges in implant dentistry. Zygomatic implants provide a graftless alternative that reduces morbidity and treatment time. However, long-term data exceeding a decade and including patient-reported outcomes remain limited. A retrospective cohort study was conducted on patients who received zygomatic implants from the year 2007 to 2024 at Rajan Dental Institute, Chennai, India. Data collected from digital archives were evaluated to calculate the cumulative survival rates of zygomatic implants. Patient-reported outcome measures (PROMs) on comfort, speech, esthetics, self-confidence, and overall satisfaction were assessed using a Likert-scale questionnaire. A total of 449 patients were rehabilitated with 945 zygomatic implants. Of these, 382 patients rehabilitated with 801 zygomatic implants were included in the study who met the inclusion criteria. The mean follow-up was 8.6 ± 4.1 years. Twenty implants failed in 14 patients, yielding a cumulative implant survival of 97.5% and patient-based survival of 96.3%. Statistical analysis demonstrated sustained survival beyond 15 years, with rates of 97.9% (4 years), 97% (8 years), 91.2% (12 years), and 81.7% (>15 years). PROMs indicated high satisfaction: >90% of respondents reported maximal improvement across all domains. This single-center analysis, with survival rates exceeding 97% over 17 years and excellent patient-reported outcomes, suggests that zygomatic implants provide a predictable and durable solution for severely resorbed maxillae. The integration of PROMs and survival modeling highlights the importance of both biological and psychosocial parameters in defining long-term success.
