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.

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.

[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.

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.

Retrospective Cohort Evaluation of Full-Arch Zirconia Implant-Supported Fixed Prostheses.

Objective: To determine the median event-free survival and relative complication rates of monolithic and minimally layered full-arch zirconia prostheses, as well as to identify risk factors for prosthesis complications. Materials and Methods: In this retrospective cohort study, a total of 129 subjects (173 prostheses) were included in the chart review and 56 subjects (75 prostheses) participated in a clinical follow-up visit. All subjects had either single- or dual-arch monolithic or minimally layered zirconia implant-supported prostheses. Data related to patient, implant, and prosthesis factors were extracted from charts. The subgroup that presented for a clinical visit were asked to complete a satisfaction questionnaire. For this subgroup, the following clinical measures were assessed: routine intraoral examination, number of occluding units, cantilever length on each side of the prosthesis (right and left), prosthesis height, occlusal scheme, and oral hygiene methods. Periapical radiographs were obtained when the last radiographs of the patient were taken more than 12 months prior. Results: The follow-up period ranged from 12 months to 7.1 years (mean: 1.9 years). Observed complications included implant loss, peri-implantitis, mucositis, purulence, sinus tract formation, oroantral communication, implant fracture, titanium base debonding, ceramic chipping, prosthetic screw fracture or loosening, damage to opposing teeth, and clicking sounds. There was an insufficient number of complications to evaluate the effect of covariates on the risk of specific complications, such as titanium base debonding (eight events), ceramic chipping (nine events), and peri-implantitis (eight events). The unadjusted event-free median survival time was 5.8 years. The proportion of all prostheses with at least one complication was 30%. There were no observed prosthesis losses during the follow-up period. Conclusion: Monolithic and minimally layered zirconia full-arch implant-supported prostheses demonstrate an acceptable median event-free survival time. Event-free survival times were increased and the number of complications was reduced in prostheses with five to eight implants and conventional (as opposed to zygomatic) implants. There was a reduced hazard of complications with a regular recall regimen. Patient satisfaction with these prostheses was high.

Masseter muscle cross-sectional area and late implant failure: A case-control study.

INTRODUCTION: Occlusal overload is considered to be one of the causes of late implant failure. However, it is unclear whether the magnitude of the patient's occlusal force is a risk factor for late implant failure. PURPOSE: This case-control study aimed to clarify the association between the cross-sectional area (CSA) of the masseter muscle and late implant failure. METHODS: This case-control study was limited to implant-supported fixed prostheses. We compared cases with at least one late implant failure (n = 25 patients) to controls (n = 82 patients) without implant failure. Patients were matched by age, sex, year of surgery, jaw and tooth type, and bone graft. Log-rank and Cox proportional hazard regression analyses were used to identify possible risk factors for late implant failure. RESULTS: The incidence of late implant failure was significantly associated with masseter muscle CSA ≥504.5 mm2 (hazard ratio: 4.43; 95% CI: 1.82-10.79; p < 0.01). CONCLUSION: Higher masseter muscle CSA increases the risk of late implant failure.

Long-term performance of implants with moderately rough anodized surface supporting single-tooth restorations: A retrospective analysis with an up to 15-year follow-up.

OBJECTIVES: This retrospective study aimed to evaluate long-term clinical and radiologic performance of anodized surface implants supporting single implant restorations. MATERIALS AND METHODS: Patients who received at least one anodized surface implant for a single-tooth restoration between 2003 and 2004 in the Brånemark clinic (Göteborg, Sweden) were included in the study. The assessed outcomes included implant survival, biological and technical complications, as well as marginal bone levels (MBL) based on radiographs. Baseline data on patient demographics, implant placement, and surgery details were also collected. The cumulative survival rate (CSR) was calculated using the Kaplan-Meier survival analysis. RESULTS: The study included 97 patients with 129 implants. Mean patient age at the time of implant placement was 31.7 ± 16.4 years. All implants were placed in a two-stage approach with delayed loading. The last follow-up visit was on average 13.4 ± 4.8 years after implant insertion. Three implants failed, yielding the implant-level 15-year CSR of 97.4%. Majority of the implants had no biological (70.5%) nor technical (81.4%) complications. The mean MBL was -1.0 ± 0.7 mm (n = 101) at prosthetic placement and -1.8 ± 1.0 mm (n = 80) at the last follow-up, while the mean marginal bone loss (MBL) from prosthetic placement to last follow-up was 0.6 ± 1.1 mm (n = 65). CONCLUSIONS: Moderately rough anodized implants have shown favorable long-term outcomessingle-tooth indication, with high survival and a low rate of technical complications. Furthermore, long-term studies are needed to present longitudinal data on peri-implantitis.

Flapless placement of zygomatic implants using dynamic navigation: an innovative technical note.

Zygomatic implants are routinely used for the rehabilitation of the midface and edentulous maxilla; the procedure is carried out under general anaesthesia and requires the direct lifting of the Schneiderian membrane. A prefabricated surgical guide is usually used to direct the position of the zygomatic implants during surgery. This proof-of-concept study explored an innovative flapless approach for placement of zygomatic implants guided by dynamic navigation. Under local anaesthesia eight zygomatic implants were placed using a flapless technique. The preplanned position of zygomatic implants was transferred to the operating theatre using dynamic navigation, which guided the sinus lift procedure and the planned osteotomy. Operative complications were recorded, the accuracy of the implant position was measured and postoperative morbidities including pain and swelling were evaluated. Surgical complications were minimal, the Schneiderian membrane was intact in all the cases except one, which required the application of resorbable collagen membrane. Satisfactory accuracy was achieved regarding the precision of implant position and angulation. One of the patients developed maxillary sinusitis three months following surgery. Postoperative pain and swelling were minimal. The dynamic navigation guided flapless placement of zygomatic implants under local anaesthesia is a feasible technique with minimal surgical complications and postoperative morbidities.

Prevalence and risk of peri-implant diseases based on the type of prosthetic restoration: A retrospective study after 17 to 23 years.

STATEMENT OF PROBLEM: Information on the epidemiology and etiopathology of peri-implant diseases in reference to prostheses is sparse. PURPOSE: The purpose of this retrospective clinical study was to analyze the prevalence and risk of peri-implant diseases based on the type of prosthesis. MATERIAL AND METHODS: A total of 274 implants in 106 patients were evaluated by clinical and radiological examination. Peri-implant mucositis was defined by bleeding on probing, whereas peri-implantitis was defined by additional bone loss ≥1.5 mm since seating of the definitive prosthesis. Prosthetic design and anamnestic risk factors were assessed in a regression analysis, whereas clinical and radiological differences between the prosthesis groups were compared by the Pearson chi-squared test (α=.05 for all procedures). RESULTS: The median observation period was 18 years. Seventy-two implants were restored with single crowns, 138 implants with fixed partial dentures, and 64 implants with removable prostheses. Peri-implant mucositis was diagnosed more often in implants supporting fixed partial dentures (42.8%), whereas peri-implantitis was found more frequently in implants supporting removable prostheses (31.3%) (overall distribution pattern: P<.001). The type of prosthetic restoration was confirmed to be an independent prognostic risk factor regarding peri-implant diseases (P=.005). Additionally, increased bone loss was found with implant-supported removable prostheses, regardless of peri-implantitis (P<.001). CONCLUSIONS: The type of prosthetic restoration was identified as an independent risk factor for the development of peri-implant diseases. Particularly, implants supporting double crown-retained removable prostheses might be at risk.

Prosthodontic complications during implant-based oral rehabilitation of patients with head and neck cancer.

STATEMENT OF PROBLEM: Implant-retained prosthodontic rehabilitation of patients with head and neck cancer is complex. However, the extent of prosthodontic complications has been sparsely reported within the literature. PURPOSE: The purpose of this retrospective study was to describe the range of complications and issues that affected the oral rehabilitation treatment of patients with head and neck cancer who had completed implant-retained prosthodontic rehabilitation in a tertiary treatment center. MATERIAL AND METHODS: A retrospective analysis of complications and their consequences in patients treated in a regional unit from 2012 to 2017 was performed. Descriptive analysis was carried out on the type and frequency of complications and their consequences for the patients' treatment. Complications were grouped into the following complication types: local and systemic, implant, peri-implant soft tissue, and clinical prosthodontic complications. Implant success and implant survival were also reported. RESULTS: The sample was composed of 163 patients with head and neck cancer who had completed implant-retained prosthodontic rehabilitation. Local and systemic complications affected 8.6% of patients, and peri-implant soft-tissue complications affected 9.8% of patients. Clinical prosthodontic complications leading to repeated clinical or laboratory stages occurred on 48 occasions in 45 patients (27.6% of patients). A total of 763 implants were placed. Implant survival was 95.8% and implant success 94.5%, with a mean follow-up of 42.1 months. CONCLUSIONS: This retrospective evaluation indicated that complications arising during the process of implant-retained prosthetic rehabilitation in this patient group were variable and common. Such complications can delay the process of treatment and lead to repeating or restarting clinical and laboratory stages of treatment.

Implant survival rate and marginal bone loss with the all-on-4 immediate-loading strategy: A clinical retrospective study with 1 to 4 years of follow-up.

STATEMENT OF PROBLEM: Assessing peri-implant marginal bone loss (MBL) and its risk factors with cone beam computed tomography (CBCT) may clarify the risk factors for the all-on-4 (5 or 6) strategy and further improve its survival rate. PURPOSE: The purpose of this retrospective clinical study was to evaluate the implant survival rate, MBL, and associated risk factors of all-on-4 (5 or 6) prostheses after 1 to 4 years of follow-up with CBCT. MATERIAL AND METHODS: A total of 56 participants rehabilitated with 325 implants by using the all-on-4 (5 or 6) concept between October 2015 and December 2019 were included. Outcome measures were cumulative implant survival (life-table analysis) and MBL. Four CBCT scans, a scan immediately after surgery (T0), a scan 1 year after surgery (T1), a scan 2 years after surgery (T2), and a scan 3 to 4 years after treatment (T3), were obtained to evaluate the MBL. The Pearson correlation coefficient analysis and linear mixed models were performed to assess the potential risk factors for MBL (α=.05). RESULTS: The implant survival rate was 99.38%, and the prosthesis survival rate was 100%. The reductions in the vertical buccal bone height (△VBBH) were 0.74 ±0.10 mm (T0-T1), 0.37 ±0.12 mm (T1-T2), and 0.15 ±0.14 mm (T2-T3). Except for T2-T3, the △VBBH showed a significant difference at T0-T1 and T1-T2 (P≤.05). The alterations in vertical mesial bone height (VMBH), vertical distal bone height (VDBH), and vertical lingual bone height (VLBH) were similar to the trend observed in VBBH. The △VBBH (T0-T3) was negatively correlated with the horizontal buccal bone thickness (HBBT) (T0) (r=-.394, P<.001). Linear mixed models revealed that factors such as smoking (P=.001), mandible implant site (P<.001), immediate implant (P=.026), tilted implant (P<.001), female sex (P=.003), systemic disease (P=.025), and bruxism (P=.022) negatively affected MBL. The cantilever length (CL) also had a negative effect on MBL around the implants at the distal extension (P<.001). CONCLUSIONS: The high implant and prosthesis survival rates and low MBL confirmed the predictability of the all-on-4 (5 or 6) concept. Smoking, mandible implant site, systemic disease, bruxism, female sex, immediate implant, tilted implant, and CL were identified as potential risk factors for MBL.

Clinical Outcomes of Metal-Ceramic versus Metal-Acrylic Resin Implant-Supported Fixed Complete Dental Prostheses: A Systematic Review and Meta-analysis.

PURPOSE: To compare the clinical outcomes of metal-ceramic vs metal-acrylic resin implant-supported fixed complete denture prostheses (IFCDPs). MATERIALS AND METHODS: An electronic literature database search was conducted in the CINAHL, EMBASE, PubMed, and Web of Science databases. Additionally, a manual search of the literature was performed. Studies conducted in edentulous human subjects comparing clinical outcomes of metal-acrylic resin IFCDPs to those of metal-ceramic IFCDPs were included if quantitative outcomes for the following variables were reported: implant failure, prosthetic failure, incidence of peri-implantitis, incidence of peri-implant mucositis, incidence of peri-implant mucosal recession, prosthetic complications, and any patient-centered outcomes. Data from included studies were pooled to estimate effect size. RESULTS: Five studies met the inclusion criteria. A quantitative analysis was possible for risk of implant failure, prosthesis failure, and incidence of peri-implantitis. Meta-analysis showed no statistically significant differences in the risk of implant or prosthesis failure between the two groups. However, meta-analysis showed a significantly greater risk of developing peri-implantitis at the implant level in the metal-acrylic group when compared to the metal-ceramic group (risk difference = 0.069; 95% CI = 0.028 to 0.06; P = .001; fixed-effects model). Furthermore, descriptive analysis of the literature indicated a higher incidence of other biologic complications such as peri-implant mucositis and peri-implant mucosal recession, as well as prosthetic complications such as abrasion and veneer fracture, in metal-acrylic resin IFCDPs compared to metal-ceramic IFCDPs. CONCLUSION: The available evidence suggests that a higher incidence of biologic and prosthetic complications, including a higher risk of peri-implantitis, are present with metal-acrylic resin IFCDPs compared to metal-ceramic IFCDPs.

Comparison of 4- or 6-implant supported immediate full-arch fixed prostheses: A retrospective cohort study of 217 patients followed up for 3-13 years.

PURPOSE: Choosing four or six implants to support immediate full-arch fixed prostheses (FAFPs) is still controversial worldwide. This study aims to analyze and compare the long-term results of All-on-4 and All-on-6. MATERIALS AND METHODS: This retrospective cohort study enrolled 217 patients rehabilitated with 1222 implants supporting 271 FAFPs, including 202 prostheses supported by 4 implants (All-on-4 group) and 69 prostheses supported by 6 implants (All-on-6 group), and followed up for 3-13 years. Implant survival, prosthesis survival, complications, and implant marginal bone loss (MBL) were evaluated and compared between two groups. Patient characteristics including age, gender, jaw, opposite dentition condition, smoking habit, bruxism, bone quantity and quality, cantilever length (CL), prosthesis material, and oral hygiene were analyzed to assess their influence on the clinical results of the two groups. Six surgeons and three prosthodontists who performed FAFPs more than 5 years were invited for questionnaires, to assess patient- and clinician-related influences on implant number. RESULT: In general, All-on-4 group indicated no significant difference with All-on-6 group in the implant survival (implant-level: hazard ratio [HR] = 1.0 [95% confidence interval (CI): 0.8-1.2], P = 0.96; prosthesis-level: HR = 0.8 [95% CI: 0.3-1.8], P = 0.54), prosthesis survival (odds ratio [OR] = 0.8 [95% CI: 0.3-2.8], P = 0.56), biological complications (OR = 0.9 [95% CI: 0.5-1.8], P = 0.78), technical complications of provisional prosthesis (OR = 1.3 [95% CI: 0.7-2.3], P = 0.42), technical complications of definitive prosthesis (OR = 1.1 [95% CI: 0.6-2.2], P = 0.33) and the 1st, 5th, and 10th year MBL (P = 0.65, P = 0.28, P = 0.14). However, for specific covariates, including elderly patients, opposing natural/fixed dentition, smoking, bruxism, long CL, low bone density, and all acrylic provisional prostheses, All-on-6 was more predictable in some clinical measurements than All-on-4. The implant prosthodontists and the medium-experienced clinicians showed significant preference for All-on-6 (P < 0.05). CONCLUSION: Based on this study, the long-term clinical results showed no significant difference between All-on-4 and All-on-6 groups in general. However, for some specific characteristics, All-on-6 seemed to be more predictable in some clinical measurements than All-on-4. For the clinicians' decision-making, medium-experienced clinicians and the implant prosthodontists showed significant preference for All-on-6.

Immediate loaded fixed complete dentures supported by implants in patients with a history of periodontitis: A retrospective cohort study of 2 to 7 years.

STATEMENT OF PROBLEM: The outcome of implant-supported fixed complete dentures in edentulous patients with a history of periodontitis is unclear. PURPOSE: The purpose of this retrospective clinical study was to assess the clinical outcomes of immediate loaded fixed complete dentures in individuals with a history of periodontitis and to analyze risk factors related to implant failure. MATERIAL AND METHODS: A total of 642 implants (146 prostheses) in 119 patients were included. The follow-up period ranged from 2 to 7 years. Implant survival rates, marginal bone loss, mechanical complications, biologic complications, and patient satisfaction were evaluated. The Pearson chi-square test, independent samples t test, and multivariate generalized estimating equation were performed for statistical analysis (α=.05). RESULTS: Eleven implants in 9 patients failed, leading to overall survival rates of 98.3% at the implant level and 92.4% at the patient level. The mean ±standard deviation marginal bone loss was 0.62 ±0.86 mm, and marginal bone loss did not differ significantly between axial and tilted implants (P>.05). Mechanical complications were detected in 55 (37.7%) definitive prostheses; biologic complications were detected in 318 (49.5%) implants. Smokers had a significantly lower survival rate than nonsmokers (odds ratio: 6.880, P=.013). Bruxers had a significantly higher incidence of mechanical complications than nonbruxers (P<.001). CONCLUSIONS: The immediate loaded fixed complete denture supported by implants is a suitable treatment option for edentulous patients with a history of periodontitis, with high survival implant rates. Smoking is a risk factor for implant failure. Bruxism may increase the incidence of mechanical complications with implant-supported fixed complete dentures, and the overall biologic complication incidence is comparatively high.

Which Patient-Related Factors Influence the Outcome of Telescopic-Retained Removable Implant-Supported Dental Prostheses in Edentulous Patients?

PURPOSE: To survey the clinical performance of telescopic-retained removable implant-supported dental prostheses (TR-RISDPs) in edentulous patients, as well as incidental maintenance measures and technical complications. MATERIALS AND METHODS: In this retrospective analysis, the former presence of oral cancer, prosthesis location (maxilla or mandible), and participation in a follow-up program were analyzed as possible factors with an influence on survival and maintenance treatments of the TR-RISDPs and dental implants using Kaplan-Meier estimates. RESULTS: A total of 86 TR-RISDPs (mean follow-up: 4.62 ± 3.24 years; maximum 13.8 years) and 465 implants (mean follow-up: 5.67 ± 3.59 years; maximum 16.5 years) were observed. Six (6.9%) of the TR-RISDPs had to be remade, and 11 (2.3%) implants failed. Regular attendance in the follow-up program showed significantly higher survival times and fewer maintenance treatments for the TRRISDPs (P < .05). Implants in patients with former oral cancer showed significantly lower survival times (P < .001). CONCLUSIONS: TR-RISDPs in edentulous patients show excellent clinical outcomes. Regular check-ups are decisive for success.