[Evaluation of the 5-year clinical restoration effect of implants retained complete overdentures with Locator attachments in 48 patients].

PURPOSE: To observe the long-term clinical effect of implants retained complete overdentures with Locator attachments. METHODS: A total of 48 patients with edentulous jaws treated with implants retained complete overdentures with Locator attachments were selected from the Outpatient Department of Peking University School and Hospital of Stomatology from 2016 to 2017. Among them, 21 patients underwent double-maxillary complete overdentures restoration and 27 patients underwent single-maxillary restoration. A total of 230 implants were implanted. The clinical observation indicators included the implant survival rate, peri-implant mucosal bleeding on probing(BOP), the change in the vertical height of alveolar bone absorption around the implants, overdenture base fracture rate, artificial tooth fall off and fracture rate and other complications. The change of the locator attachment retention force of the implant-supported overdentures was evaluated. SPSS 13.0 software package was used for data analysis. RESULTS: During the five-years clinical observation period, 5 implants fell off, 1 narrow dimeter implant in the anterior zone was broken, and 12 implants were lost to follow-up. The implant survival rate was 97.25%. One year after the restoration therapy finished, peri-implant mucosal bleeding on probing (BOP+) was detected in 48 (21.4%) implants. The average BI was 0.21±0.42, which was higher in the anterior zone than that in the posterior zone. The vertical alveolar bone absorption height around the implants was (0.21±0.35) mm, 2 implants-supported complete overdenture bases were broken. After 5 years of restoration, 163(76.89%) implants had peri-implant mucosal bleeding on probing(BOP+). The average BI was 1.00±0.70, and the vertical alveolar bone absorption height around the implants was (0.58±0.85) mm. There was no significant difference between males and females. There was no significant difference in the peri-implant mucosal bleeding index and the alveolar bone vertical absorption height between the anterior zone and the posterior zone(P＞0.05). The mean BI of peri-implant mucosa and the vertical absorption height of peri-implant alveolar bone were significantly different between the 1-year observation period and the 5-year observation period respectively(P＜0.01). There were 17(26.15%) cases with overdenture bases fracture, and the fracture rate of artificial teeth was 16.92%. Most of them occurred in the midline area of the anterior zone and the location of the overdenture base on the locator attachments. The average first replacement time of the locator attachment nylon retainer washer was 34.2±10.3 months. CONCLUSIONS: Implants retained complete overdentures with Locator attachments are effective in long term clinical observation. Complications are mainly found in peri-implant mucosal bleeding on probing and vertical alveolar bone absorption, and tended to increase gradually over time. The fracture of the implant retains complete overdenture bases and the fall off or fracture of the artificial teeth are the second serious complications. Overdenture base with metal frame at the location of the Locator abutment and the midline of the anterior area should be strengthened, and narrow diameter implants should be avoided as far as possible in the anterior zone.

Radiographic evaluation of the distance between the restoration margin and the alveolar bone crest in dental implant patients: A retrospective study.

OBJECTIVES: The recently introduced Implant Disease Risk Assessment (IDRA) identifies a restoration margin-alveolar bone crest (RM-AC) distance of less than 1.5 mm as a key risk factor for peri­implant disease among eight major risk factors. This study evaluated the impact of the RM-AC distance on marginal bone loss (MBL) through radiographic analysis. METHODS: This retrospective cross-sectional study included 77 partially edentulous patients (39 females and 38 males, aged 22 to 76 years) with 202 platform-switched conical connection implants, cement-retained, implant-supported fixed restorations, and bone-level implants placed between 2016 and 2021. Dental implants were followed for least 6 to 36 months at follow up functional loading. Study participants were categorized into Group A (RM-AC distance ≤ 1.5 mm, n = 69) and Group B (RM-AC distance > 1.5 mm, n = 133). Twelve patients in Group B and five patients in Group A had no history of periodontal disease. The MBL was measured radiographically from the most coronal point of the implant shoulder to the alveolar bone, and the RM-AC distance was measured from the restoration margin to the alveolar crest. Multinomial logistic regression analysis was used for statistical evaluation. RESULTS: The incidence of MBL in Group A was statistically significant and 3.42 times higher than that in Group B. The rate of MBL in periodontitis Stage 4 was found to be 26.31 times higher than that in periodontitis Stage 2. The incidence of MBL was 6.097 and 5.02 times higher with increasing implant diameter and length, respectively. CONCLUSION: This study conclusively demonstrates that RM-AC distance ≤ 1.5 significantly increases the risk of MBL, particularly in patients with a history of periodontal disease. CLINICAL SIGNIFICANCE: This study highlights the critical role of maintaining an RM-AC distance greater than 1.5 mm in the prevention of MBL, particularly in patients with a history of periodontal disease. Since implant diameter and length have a significant impact on the risk of MBL, it emphasizes that implant demographics should also be carefully evaluated.

Clinical performance of additively manufactured subperiosteal implants: a systematic review.

PURPOSE: The aim of this study was to assess implant survival and complications rate of modern subperiosteal implants (CAD designed and additively manufactured). METHODS: A systematic review was conducted using three electronic databases; Medline (Pubmed), Cochrane library, and SCOPUS, following the PRISMA statement recommendations to answer the PICO question: "In patients with bone atrophy (P), do additively manufactured subperiosteal implants (I), compared to subperiosteal implants manufactured following traditional approaches (c), present satisfactory implant survival and complication rates (O)? The study was pre-registered in PROSPERO (CRD42023424211). Included articles quality was assessed using the "NIH quality assessment tools". RESULTS: Thirteen articles were finally selected (5 cohort studies and 8 case series), including 227 patients (121 female / 106 male; weighted mean age 62.4 years) and 227 implants. After a weighted mean follow-up time of 21.4 months, 97.8% of implants were in function (5 failures reported), 58 implants (25.6%) presented partial exposure, 12 patients (5.3%) suffered soft tissue or persistent infection. Fracture of the interim prosthesis was reported in 8 of the155 patients (5.2%) in which the use of a provisional prosthesis was reported. A great heterogeneity was found in terms of study design and methodological aspects. For this reason, a quantitative analysis followed by meta-analysis was not possible. CONCLUSIONS: Within the limitations of this study, modern additively manufactured subperiosteal implants presented a good survival in the short-time, but a noticeable number of soft-tissue related complications were reported. Further studies are needed to assess the clinical behavior in the medium- and long-term.

Long-term clinical performance of short 6-mm implants supporting single crowns in the posterior region: A 10-year cohort study.

INTRODUCTION: Long-term clinical success of non-splinted, posterior, and short implants still is unclear. This prospective cohort study reports the 10-year follow-up of 6-mm implants supporting single crowns in the posterior region, and patient-reported outcomes. METHODS: Baseline sample comprised 20 patients treated with 46 screw-retained crowns supported by 6-mm implants with moderately rough implant surface. Participants were recalled for a 10-year clinical follow-up to assess survival rates, biologic and mechanic conditions, quality of life (OHIP-14), and treatment satisfaction. Data were collected with clinical-radiographic exams and analyzed using descriptive and inferential statistics. RESULTS: Fourteen patients with 35 implant-crown units were examined after 127.6 ± 11.8 months. For the entire cohort period, 7/46 implants were lost (survival estimate: 77.7% at 133 months), and mechanic complications occurred in 14/46 units (survival estimate: 66.4% at 116 months). In the Cox models, "maximum occlusal force" had a significant effect for implant loss (p = 0.038) and for prosthetic screw loosening (p = 0.038); "arch" and "bruxism" were not significant. Peri-implant bone loss was 0.4 ± 0.6 mm at 10 years. For peri-implant bone level, "crown-to-implant ratio" (p < 0.001) and "time" (p = 0.001) were significant. Bone levels differed from baseline to 12, 48, and 120 months. Satisfaction VAS was 94.0 ± 7.9 mm and OHIP-14 was 2.3 ± 2.2. CONCLUSION: Single screw-retained crowns supported by 6-mm implants have an acceptable long-term clinical performance, with stable peri-implant bone levels after 10 years of function.

Patient-reported outcomes following dental implant rehabilitation according to reason for missing teeth: A survey from a Norwegian population 8 years following treatment.

AIM: The aim of this study was to assess patient-reported outcomes (PROs) 8 years after dental implant rehabilitation in a sample with tooth loss due to periodontitis (TLP) and a sample with missing teeth for other reasons (MTOR). MATERIALS AND METHODS: The Norwegian National Insurance Scheme registry of subsidized dental implant therapy was searched, and patients (n = 3083) rehabilitated with dental implants in 2014 were mailed a questionnaire. PROs were described by relative frequencies, and the TLP and MTOR subsamples were compared using chi-square test. Multiple linear regression analyses were used to investigate variables potentially predicting PROs. RESULTS: Of the respondents (n = 1299), more than 90% were partly or fully satisfied with the treatment outcome. Complications were reported by 44.2%. Patients who lost teeth due to periodontitis (n = 784) reported greater oral function improvement and better pre-treatment information, and were more likely to experience complications when compared with patients who lost teeth for other reasons (n = 515). Age, level of education, self-funded cost, pre-treatment information, history of complications and the reason for missing teeth were found to predict PROs. CONCLUSIONS: In a Norwegian population rehabilitated with dental implants in 2014, satisfaction with the treatment outcome and the aesthetic outcome was high, irrespective of the reason for missing teeth. Self-report of complications and lack of pre-treatment information were the strongest predictors of inferior patient satisfaction and also predicted inferior oral function.

Evaluation of Prosthetic Complications with Metal-Acrylic Resin Implant-Fixed Complete Dentures: A Medium- and Long-Term Retrospective Analysis with Up to 13 Years of Follow-up

PURPOSE: To present prosthetic complications observed in the medium and long term in patients treated with metal-acrylic resin implant-supported fixed complete dentures (MAIFCDs). MATERIALS AND METHODS: A total of 87 patients who were treated with MAIFCDs were included. Acrylic resin (denture teeth and base) fracture, screw loosening (prosthetic or abutment), screw (prosthetic or abutment), and framework fracture were analyzed for descriptive statistics. Product-limit survival estimates were used for the cumulative no-complication rate (CNCR) of prostheses. All results were assessed using α = .05. RESULTS: The average observation time was 42.9 months (range: 19 to 153). Of 597 implants, 8 mandibular (44.4%) and 10 maxillary implants (55.6%) failed. In total, 29 patients (33.3%) experienced no complications in an average of 7 years, and 58 patients (66.6%) experienced at least one complication. The average time for the first complication to occur was 23 months (range: 1 to 97 months). The average number of complications was 5.9/patient. Acrylic resin complications were the most frequent, followed by screw loosening, screw fracture, and framework fracture. Of those patients with complications, 9 (16%) had maxillary MAIFCDs with an average of 4 complications. In total, 28 patients (48%) had only mandibular MAIFCDs with an average of 5 complications, and 21 patients (36%) had both arches treated with MAIFCDs with an average of 9 complications. Mandibular MAIFCDPs in women had a higher CNCR compared to maxillary MAIFCDs of both women and men and when both arches of women were treated with MAIFCDs (P < .05). CONCLUSIONS: The CNCR of MAIFCDs differed depending on the arch treated and sex. Mandibular MAIFCDs in women had a lower complication rate than MAIFCDs in other arch-sex pairs. Acrylic resin related complications were commonly observed as well as prosthetic screw loosening.

Difference in marginal bone loss around implants between short implant-supported partial fixed prostheses with and without cantilever: a retrospective clinical study.

PURPOSE: To investigate the influence of cantilever prosthetic arm on the marginal bone loss (MBL) over time around dental implants supporting short fixed partial dentures (FPDs), in a record-based retrospective study. METHODS: All cases of 3-unit implant-supported FPDs, supported by 2-3 implants, from the database of cases treated at one specialist clinic were considered for inclusion. Only implants with a minimum of 36 months of radiological follow-up were considered. Univariate linear regression models were used to compare MBL over time between 12 clinical covariates, after which a linear mixed-effects model was built. RESULTS: One-hundred-thirty-nine patients (64 men, 75 women) with 164 3-unit implant-supported FPDs (333 implants supporting non-cantilevered FPDs, 94 supporting cantilevered FPDs) were included in the study. The patients were followed up clinically and radiographically for a mean of 154.1 ± 78.0 (min-max, 37.3-364.6) and 132.9 ± 77.3 months (min-max, 36.8-329.9), respectively. The total number of marginal bone level double measurements (mesial and distal sides of each implant) was 2909. FPDs with cantilever presented an estimated greater MBL over time compared to FPDs without cantilever. Bruxism, sex (women), implant (modified) surface, and (poor) bone quality were also associated with higher MBL over time. CONCLUSIONS: The use of a cantilever extension is suggested to negatively affect the bone marginal level over time around implants supporting 3-unit FPDs. Due to the small difference of the estimated MBL over long periods of follow-up between the groups, it is a matter of debate if the observed negative effect may be of clinical significance.

Survival and complication rates of two dental implant systems supporting fixed restorations: 10-year data of a randomized controlled clinical study.

OBJECTIVES: To compare clinical, radiographic, biological and technical long-term outcomes of two types of dental implants over a period of 10 years. MATERIALS AND METHODS: Ninety-eight implants were placed in 64 patients, randomly allocated to one of two manufacturers (AST and STM). All implants were loaded with fixed restorations. Outcome measures were assessed at implant insertion (Ti), at baseline examination (TL), at 1, 3, 5, 8 and 10 (T10) years. Data analysis included survival, bone level changes, complications and clinical measures. RESULTS: Re-examination was performed in 43 patients (23 AST and 20 STM) at 10 years. The implant level analysis was based on 37 (AST) and 32 (STM) implants. Survival rates of 100% were obtained for both groups. The median changes of the marginal bone levels between baseline and T10 (the primary endpoint) amounted to a loss of 0.07 mm for group AST and a gain of 0.37 mm for group STM (intergroup p = 0.008). Technical complications occurred in 27.0% of the implants in group AST and in 15.6% in group STM. The prevalence of peri-implant mucositis was 29.7% (AST) and 50.1% (STM). The prevalence of peri-implantitis amounted to 0% (AST) and 6.3% (STM). CONCLUSIONS: Irrespective of the implant system used, the survival rates after 10 years were high. Minimal bone level changes were observed, statistically significant but clinically negligible in favor of STM. Technical complications were more frequently encountered in group AST, while group STM had a higher prevalence of peri-implant mucositis.

Clinical Assessment of Short (> 6 mm and ≤ 8.5 mm) Implants in Posterior Sites with an Average Follow-Up of 74 Months: A Retrospective Study.

PURPOSE: To evaluate the survival and success rates of short (> 6 mm and ≤ 8.5 mm) implants after at least 2 years of functional loading. Implants were assessed using clinical parameters such as marginal bone loss (MBL), pocket depth (PD), keratinized mucosa width (KMW), bleeding on probing (BoP), and the peri-implant condition (mucositis or peri-implantitis). Any correlations between clinical parameters were analyzed. MATERIALS AND METHODS: This observational and retrospective study included 114 posterior maxillary and mandibular implants placed in 27 women and 38 men with a mean age of 68.04 ± 9.07 years. Patients included in the study had received at least one short implant between 2001 and 2013, such that each implant was in occlusal function for at least 2 years by 2015. Patients with only long (≥ 10 mm) implants, patients with any systemic condition, and smokers were excluded from the study. PD, KMW, peri-implant condition, BoP, and MBL were the clinical parameters assessed in the study. Data on prosthesis type (single or splinted) and implant features were also obtained. All data were submitted to analysis via Mann-Whitney unpaired test, with a significance level of P < .05. Spearman correlation coefficient was also measured to verify the negative or positive correlation. RESULTS: The mean follow-up time was 74.08 months, and mean implant success and survival rates were 87.63% and 94.74%, respectively. There were 6 implant failures (5.26%). A total of 66 (59.46%) prostheses were screw-retained implant-supported restorations, and 45 (40.54%) were cemented. A total of 93 (86.49%) short implants were splinted to another implant, and 15 out of 111 (13.51%) restorations were single implants. Keratinized mucosa was missing around 43 (39%) implants, whereas PD was measured to be between 0 and 3 mm in 64.86% of implants and ≥ 4 mm in 31.53% of implants. MBL was ≤ 1.5 mm in 71.17% of cases and > two-thirds the length of the implant in 2.71% of cases. Mucositis and peri-implantitis were found in 22.52% and 7.21% of implants, respectively. The correlation coefficient showed a positive result for PD and MBL (0.11; P = .368) and negative results for PD and KMW (-0.42; P = .002) and KMW and MBL (-0.19; P = .183). CONCLUSIONS: Within the limitations of this study, it is possible to conclude that short implants are a feasible treatment option for dental rehabilitation. They are considered an excellent alternative to complex procedures and have high survival rates after at least 2 years of follow-up, with compatible peri-implant local tissue response. Moreover, a significant negative correlation between KMW and PD was observed.

Rehabilitation with implant-supported overdentures in preteens patients with ectodermal dysplasia: A cohort study.

INTRODUCTION: Hypohidrotic ectodermal dysplasia (HED) patients suffering of oligo-anodontia require early dental treatment to improve oral functions and reduce social impairment. The aim of this study was to evaluate the skeletal growth, implant and prosthetic survival rate, success, and complications after the rehabilitation with a maxillary denture and an implant-supported overdenture provided by a sliding bar in case of severe hypodontia/anodontia related to HED. MATERIALS AND METHODS: This retrospective cohort study began in 2009. Nine patients over 7 years old with HED and associated oligo-anodontia who presented at the University of Bologna for dental treatment were included in the study. They were first treated with conventional dentures and then with a maxillary denture and an implant-supported overdenture with a sliding bar connected to two implants placed in the anterior mandible. The subjects treated were followed for 3-12 years. In each case, orthopanoramic and lateral cephalometric radiographic exam were taken before implant placement and annually after prosthetic load. Vertical and transverse dimensions of the mandible in the symphysis area at implant sites were taken on the lateral cephalometric radiography at the time of implant placement and after 5 years from the prosthetic loading to assess the presence or absence of an anterior mandibular growth. Biologic and mechanical complications were also recorded at every visit. RESULTS: A mandibular vertical growth under the implant apex, at the implant neck, and a sagittal growth of the symphysis after 5 years from the prosthetic loading were observed and measured. Implant and prosthetic success and survival rates were 100% after 8.1 years (mean) follow-up period. No complications were reported except in one patient, where the repositioning of a retentive cap on the counter bar in the superstructure was necessary after 3 years from the prosthetic loading. CONCLUSIONS: The present study suggests that the growth of the mandible near implant sites continues even after their positioning. Implants can be successfully placed and provide support for prosthetic rehabilitation in preteens patients with HED.

Comparison of Implant Survival Rates and Biologic and Mechanical Complications with Implant-Supported Fixed Complete Dental Prostheses Using Four and Six Implants.

This study aims to compare the incidence of biologic and mechanical complication rates and the survival rates after at least 5 years of implants and implant-supported fixed complete dental prostheses (IFCDPs) placed during second-stage surgery using four and six implants. A total of 77 patients (33 men, 44 women) with a mean age of 60.6 ± 8.8 years (range: 39 to 80 years) were included, and the total of 92 IFCDPs were classified into two groups: 51 received four implants, and 41 received six implants. No implant failed in the four-implant group (0/204), and one implant failed in the six-implant group (1/246), with no statistically significant differences (P > .05). One prosthetic failure occurred in the four-implant group (1/51), and one failure occurred in the six-implant group (1/41). Both groups experienced some technical and biologic complications, with no statistically significant differences between the groups (P > .05). For both groups, veneer or resin fracture was the most frequent mechanical complication, and mucositis was the most frequent biologic complication. The use of four or six implants may represent a predictable treatment option in the rehabilitation of completely edentulous patients with IFCDPs in the medium-term.

Five years clinical outcome of maxillary mini dental implant overdenture treatment: A prospective multicenter clinical cohort study.

BACKGROUND: The long-term clinical outcome of mini dental implants (MDIs) to support an overdenture is underreported especially in severely atrophic maxillae and when installed flaplessly. PURPOSE: The current report is a 5-years follow-up of the previously published 2- and 3-years clinical outcome of MDIs supporting a maxillary overdenture in narrow alveolar ridges. MDI survival, marginal bone level, peri-implant health, technical complications, and oral health related quality of life (OHIP) and respective changes over time are reported. MATERIALS AND METHODS: Subjects aged 50 years or older, in need of improvement of maxillary denture retention, were included. The MDIs were 2.4 mm diameter one-piece tapered implants, Class 4 pure Titanium, and lengths 10 or 11.5 mm. Under local anesthesia, 5-6 MDIs were placed in atrophic maxillae with a free-handed flapless approach. One week postoperative the denture was adapted with a retentive soft reliner. The final prosthetic connection was established after 6 months with a metal-reinforced horse-shoe denture. Clinical outcome after 5 years was assessed with probing pocket depts (PPD), bleeding on probing (BoP), and additional cone beam computed tomography (CBCT) MDI bone level measurements were performed. Oral Health-Related Quality of Life (OHRQoL) investigated with OHIP-14 was assessed preoperative, during provisional loading, and after final prosthetic connection up to 5 years. RESULTS: Initially, 31 patients (14 females and 17 males) with mean age 62.30 underwent treatment. In the provisional loading interval, 16 patients encountered 32/185 MDIs failures, resulting in a failure of 17.3%; 170 MDIs were functionally loaded in 29 patients. Additionally, 14 implants were lost in three patients, all of whom had had already previous failures. Reimplantation of 17 MDIs were performed during the provisional loading and 2 MDI after functional loading. After 5 years, the absolute implant failure rate was 46/204 (22.5%), corresponding to a cumulative failure rate of 23.2%. Prosthetic failure was observed in four patients due to implant loss and in two patients related to excessive one-piece implant ball attachment wear, making the 5-years prosthetic success 80.0%. The mean PPD and absence/presence of BoP for 149 implants at 5 years was 4.3 and 0.2 mm, respectively. Average mesial-distal-vestibular-palatal bone loss in the interval 2-5 years was 0.08 mm. No statistically significant difference in marginal MDI bone loss between male or female (p = 0.835), smoking and nonsmoking (p = 0.666) was observed. The five-years total measured CBCT interdental bone level (mesial and distal) correlates with the 5-years PPD (Pearson 0.434; p = 0.01). After 5 years, OHRQoL with the treatment procedure was assessed in 27/31 participants. Decreasing mean total OHIP-14 scores with improved OHRQoL, was observed in 27/31 participants, with values of 21.3 at baseline to 15.6 at the time of provisional loading which significantly (p = 0.006) decrease to 7.3 at the final prosthetic connection. The next 3-5 years further decrease was observed with 6.5 and 4.96, respectively. CONCLUSIONS: Maxillary MDIs for overdentures are an accessible and acceptable treatment option. Although after 5 years between one fifth and one fourth of the MDIs were lost, prosthetic success remains 80.0% and high OHRQoL could be achieved.

Influence of Keratinized Tissue on Short Dental Implants: A Parallel Cohort Retrospective Study on 217 Implants with a Mean Follow-up of 4.1 Years.

PURPOSE: To assess whether the presence or absence of keratinized tissue height (KTh) may have an influence on marginal bone levels, complications, and implant survival for short implants. MATERIALS AND METHODS: The study was designed as parallel cohort retrospective research. Short implants with an implant length < 7 mm were considered. One cohort was composed of patients with short implants surrounded by ≥ 2 mm of KTh (adequate KTh); the other cohort included implants with < 2 mm of KTh (not-adequate KTh). Outcome measures were marginal bone level (MBL) changes, failures, and complications. RESULTS: One hundred ten patients treated with 217 short and extrashort implants (4 to 6.6 mm long) were retrospectively included. The mean follow-up was 4.1 years after prosthetic loading (range: 1 to 8 years). The differences between KTh groups in MBL were not statistically significant at every follow-up considered: 0.05 mm at 1 year (P = .48), 0.06 mm at 3 years (P = .34), 0.04 mm at 5 years (P = .64), and 0.03 at 8 years (P = .82). A total of nine complications were reported: three in the not-adequate KTh group and six in the adequate group; the difference was not statistically significant (OR: 3.03, 95% CI: 0.68 to 13.46, P = .14). Five implants failed due to peri-implantitis, two in the not-adequate KTh group and three in the adequate group, without a statistically significant difference (OR: 2.76, 95% CI: 0.42-17.99, P = .29). CONCLUSION: This study showed no statistically significant differences in MBL, complications, and implant failure rates between short implants with adequate or not-adequate KThs. However, given the importance of patient comfort while brushing and plaque accumulation, keratinized tissue grafts could be important in selected patients, especially for those who are severely atrophic, also taking into consideration all the limitations of this study and the mediumterm follow-up. Nevertheless, longer follow-ups, larger numbers of patients, and randomized controlled clinical trials are needed before making more reliable clinical recommendations. Int J Oral Maxillofac Implants 2023;38:462-467. doi: 10.11607/jomi.9918.

Splinting or Nonsplinting Adjacent Implants? A Retrospective Study Up to 15 Years: Part I-Biologic and Mechanical Complication Analysis.

PURPOSE: To analyze the biologic and mechanical complications of splinted and nonsplinted implant restorations. MATERIALS AND METHODS: A total of 423 patients (n = implants: 888) were included in the study. Biologic and mechanical complications that occurred for 15 years were analyzed using the multivariable Cox regression model, and the significant effect of the splinting of prostheses and other risk factors were evaluated. RESULTS: Biologic complications occurred in 38.7% of implants: 26.4% of nonsplinted implants (NS) and 45.4% of splinted implants (SP). Mechanical complications occurred in 49.2% of implants: 59.3% NS and 43.9% SP. Implants splinted with both mesial and distal adjacent implants (SP-mid) had the highest risk of peri-implant diseases. As the number of implants splinted increased, the risk of mechanical complications decreased. Long crown lengths increased the risk of both biologic and mechanical complications. CONCLUSION: Splinted implants had a higher risk of biologic complications and lower risk of mechanical complications. The implant splinted to both adjacent implants (SP-mid) had the highest risk of biologic complications. The greater the number of implants splinted, the lower the risk of mechanical complications. Long crown lengths increased the risk of both biologic and mechanical complications. Int J Oral Maxillofac Implants 2023;38:435-442. doi: 10.11607/jomi.10053.

Maxillary Full Arch Restorations - Biological Complications: A Narrative Review Outlining Criteria for Long Term Success.

PURPOSE: Patients receiving full arch implant borne maxillary prostheses require functional, esthetic, and long term success. The importance of this review is to document the difficulty with implant maintenance, the prevalence of peri-implant disease, and the improvement in biologic health when using a prosthesis that can be maintained to minimize plaque. The objective is to provide surgeons with a reference to optimize surgical procedures that can result in improved hygiene and long term maintenance, as well as acceptable functional and esthetic goals. METHODS: Pubmed.gov was the information source. Years reviewed included 1990-2022. Inclusion criteria included only articles in journals referenced in pubmed.gov. The reports excluded were case reports, reports that only included implant survival, and articles without a statistical analysis to generate meaningful conclusions. Biological complications included bone loss, hygiene difficulty, mucositis and recession, the incidence of peri-implantitis, and how complications related to patient co-morbidities. Data collected included outcomes of the study including statistical significance. RESULTS: The search identified articles for review using terms which included full arch maxillary restorations (n = 736), long term success with full arch maxillary prostheses (n = 22), ceramic full arch restorations (n = 102), and complications with full arch restorations (n = 231). From this search, 53 articles were collated that satisfied the inclusion criteria. Factors found to be significant contributors to biological complications included bone loss and peri-implant disease, difficulty with daily hygiene access, plaque and biofilm coverage, and the need for continued maintenance for long term implant health. CONCLUSION: The surgeon needs to place implants to allow a full arch maxillary prosthesis to be fabricated with full access to the implants for maintenance, which should decrease the incidence of biological complications. With excellent maintenance full arch implant restorations can have limited peri-implant disease.

Risk factors associated with loss of variable-thread tapered implants: A retrospective observational study of 1-5 years.

OBJECTIVES: This study aimed to evaluate the survival rate of variable-thread tapered implants (VTTIs) and identify risk factors for early/late implant loss. MATERIALS AND METHODS: From January 2016 to December 2019, patients who received VTTIs were included in this study. The cumulative survival rates (CSRs) at implant/patient levels were calculated by the life table method and presented via Kaplan-Meier survival curves. The relation between investigated variables and early/late implant loss was analyzed by the multivariate generalized estimating equation (GEE) regression model on the implant level. RESULTS: A total of 1528 patients with 2998 VTTIs were included. 95 implants from 76 patients were lost at the end of observation. At the implant level, the CSRs at 1, 3, and 5 years were 98.77%, 96.97%, and 95.39%, respectively, whereas they were 97.84%, 95.31%, and 92.96% at the patient level, respectively. The multivariate analysis revealed that non-submerged implant healing (OR = 4.63, p = .037) was associated with the early loss of VTTIs. Besides, male gender (OR = 2.48, p = .002), periodontitis (OR = 3.25, p = .007), implant length <10 mm (OR = 2.63, p = .028), and overdenture (OR = 9.30, p = .004) could significantly increase the risk of late implant loss. CONCLUSION: Variable-thread tapered implants could reach an acceptable survival rate in clinical practice. Non-submerged implant healing was associated with early implant loss; male gender, periodontitis, implant length <10 mm, and overdenture would significantly increase the risk of late implant loss.

[Analysis of clinical effects and risk factors of short implant followed up for 7-9 years].

PURPOSE: To evaluate the long-term clinical efficacy of short implants and analyze the influencing factors of the survival rate. METHODS: A total of 178 patients who received implant therapy in the Department of Stomatology, the Fourth Affiliated Hospital of Nanchang University from January 2010 to December 2014 were selected, including 334 short implants of Bicon (implant length ≤6 mm). The basic condition, restoration design, short implant survival rate and complications were observed and analyzed. SPSS 24.0 software package was used for data analysis. RESULTS: The average follow-up time of short implants was 96±17 months. During the observation period, 20 implants failed, 1 implant had mechanical complications and 6 implants had biological complications. Based on the analysis of implants and patients, the long-term cumulative survival rate of short implants was 94.0%(over 5 years survival rate was 96.4%) and 90.4% respectively. There was no significant difference between the survival rate of short implants and the patient's gender, age, whether to use special operation and the type of jaw teeth(P＜0.05). Smoking and periodontitis were risk factors for failure of short implants(P＜0.05).The difference of short implant survival rate between short implants restoration with combined crowns and single crowns was statistically significant(P＜0.05). The survival rate of short implant in mandible was higher than that in maxilla(P＜0.05). CONCLUSIONS: Under the standards clinical program and operation, short implant can be used to shorten the implant restoration cycle and avoid complicated bone augmentation which can achieve good long-term clinical effect. Short implant should be used to strictly control the risk factors that affect the survival of short implant.

Implant survival/success and peri-implant outcomes of titanium-zirconium mini implants for mandibular overdentures: Results from a 1-year randomized clinical trial.

OBJECTIVE: To report the 1-year implant survival/success and peri-implant outcomes of mandibular overdentures retained by four titanium-zirconium mini implants (Straumann® Mini Implant System), and to assess how surgery and loading protocols influence these outcomes. MATERIALS AND METHODS: A 2 × 2 factorial randomized clinical trial (RCT) tested the combined effects of two loading protocols (immediate or delayed) and two surgical approaches (flapless or flapped) on the success/survival of the mini implants, and peri-implant parameters (plaque, bleeding, sulcus depth, gingival position, and marginal bone loss). Outcomes were assessed up to 1-year after loading, and generalized estimating equations (GEEs) were used to analyze longitudinal and within-patient clustered data. RESULTS: Two hundred and ninety-six implants were placed in 74 patients. The implant survival/success rates after 1 year were 100%, and no major biological complications were observed. After 1-year, descriptive data suggest no noticeable changes in plaque scores, whilst a reduction in bleeding scores at the 6-month and 1-year follow-ups compared to baseline. Good longitudinal stability was observed for the probing depth and gingival margin height measures. Overall mean marginal bone loss was 0.68 (±0.68) mm after 3 months and 0.89 (±0.75) mm after 1-year. The flapless protocol showed better results on soft tissue stability and health but a slightly higher risk for marginal bone loss. CONCLUSION: The results of this RCT suggest that mandibular overdentures retained by this novel mini implant system represent a safe and predictable treatment option as confirmed by implant survival/success and peri-implant outcomes, even when flapless surgery and immediate loading protocols are adopted.

Catastrophic implant failure after immediate loading of full arch implant prosthesis and its association with CPAP therapy: A case report.

Full arch implant-supported restorations are a common treatment modality for patients with a terminal dentition or an edentulous mouth. Several mechanical and biological factors that contribute to complications or failure are already extensively documented. Some patients receiving complex implant-based treatment plans also suffer from obstructive sleep apnea (OSA). The use of a continuous positive airway pressure (CPAP) mask in some of these patients is a lesser-known factor that could contribute to implant complications or failures. This article describes how the use of a CPAP machine may be a risk factor in implant dentistry and describes a patient whose use of a CPAP machine and mask led to a catastrophic failure of mandibular full arch dental implants.

Implant Survival and Complication Prevalence in Complete-Arch Implant-Supported Fixed Dental Prostheses: A Retrospective Study with a Mean Follow-up of 5 Years.

Purpose: To evaluate the implant survival and the prevalence of biologic and mechanical complications in edentulous patients restored with complete-arch implant-supported fixed dental prostheses (IFDPs). Materials and Methods: Patients restored with complete-arch screw-retained IFDPs between January 2012 and December 2019 with a minimum 2-year follow-up were included. Outcome measures were cumulative survival rate (CSR) for implants and prostheses, biologic complications, and mechanical complications. A generalized estimating equation model was used to estimate potential risk factors for mechanical complications. Patient satisfaction was investigated using a standardized questionnaire. Results: A total of 44 prostheses supported by 268 implants in 30 patients were included for a mean duration of 4.8 years (range: 2 to 9 years). Eighteen of the prostheses were zirconia-ceramic (group ZC), and 26 were titanium-ceramic (group TC). The CSR for the implants and IFDPs was 99.3% (95% CI: 98.2% to 100.3%) and 92.5% (95% CI: 84.2% to 100.8%), respectively. The most common biologic complication was peri-implant mucositis (4.5%), followed by peri-implantitis (3.0%). The most common mechanical complication was ceramic chipping (45.5%), followed by crown debonding (13.6%) and framework fracture (4.5%). There was no significant difference in the prevalence of complications between groups TC and ZC (P > .050). The presence of cantilever (OR = 5.54, P = .048) and maxillary arch (OR = 5.94, P = .041) were significantly associated with mechanical complications. Patient satisfaction scores were generally high, but some continued to be bothered by speech problems (13.6%). Conclusion: Complete-arch IFDPs presented reliable clinical outcomes for edentulous patients with a high implant survival rate and a high level of patient satisfaction. However, a high incidence of mechanical complications occurred in the long term.