A systematic review and meta-analysis of removable and fixed implant-supported prostheses in edentulous jaws: post-loading implant loss

Treatment Outcomes of Four-Implant-Retained Maxillary Palateless Overdenture: A 5-Year Observational Study

INTRODUCTION

Palateless overdentures (PLODs) provide advantages of improved taste perception and retention over conventional dentures. We aimed to evaluate 5-year outcomes of four implant maxillary PLODs.

METHODS

In this prospective observational study, edentulous participants were enrolled. A new conventional maxillary denture was prepared followed by implant placement and insertion of four implant retained maxillary PLOD. Oral health quality of life was assessed using the 49-item Oral Health Impact Profile (OHIP-49) at multiple intervals over 5 years along with biological and mechanical outcomes.

RESULTS

Nine patients were evaluated at year 5. The mean age was 68 years, and six of the nine patients were males. The cumulative survival rate of implants was 100% while the implant success rate was 86%. Nylon retentive replacement was the most common encountered complication noted approximately four times per patient over 5 years. From a mean OHIP-49 severity score of 71.2 at baseline, severity scores decreased to 23.9 (p < 0.001) at year 1, denoting a clinically meaningful and statistically significant improvement in oral health quality of life. The lowered OHIP-49 severity scores remained stable throughout 5 years of follow-up.

CONCLUSION

Four implant supported maxillary overdenture appears to have good patient perceived, biological and mechanical outcomes over 5 years. Fully powered studies are needed to replicate these findings.

Four locator attachments of mandibular implant-retained overdentures with two different distributions: A 10-year retrospective preliminary study of residual alveolar ridge changes

OBJECTIVES

There is little information on the long-term function of the four Locator attachment of the mandibular implant retained overdenture (OD), particularly with different distributions.

PURPOSE

To compare the effect of different four inter-foraminal implant distributions retaining a mandibular OD after 10 years of function on posterior mandibular ridge resorption (PMandRR), anterior maxillary ridge resorption (AMaxRR), and the amount of marginal bone loss (MBL) around all four implants.

MATERIALS AND METHODS

Twenty-two participants with total edentulism who had worn mandibular OVDs retained by four inter-foraminal implants for 10 years of functional life were selected for this study. They were divided into two groups based on implant distribution: Group I with a quadrilateral distribution (QD) of implants and Group II with a linear distribution (LD) of implants. PMandRR, AMaxRR, and MBL around implants were measured.

RESULTS

After 10 years of function, PMandRR was significantly higher in the LD group than in the QD group (p < 0.001*). There was no significant difference in AMaxRR between the QD and LD groups (p = 0.431). The QD group showed a significantly greater amount of MBL around dental implants when compared with the LD group (p = 0.002*).

CONCLUSIONS

The LD of implants demonstrates more PMandRR compared with the QD. The QD of implants demonstrates a greater amount of MBL around dental implants compared with the LD. Both implant distributions demonstrate the same effect on the AMaxRR. MBL around implants remained within normal accepted values after 10 years of function.

Accuracy of implant abutment level digital impressions using stereophotogrammetry in edentulous jaws: an in vitro pilot study

BACKGROUND

In edentulous jaws, factors such as the number of implants, cross-arch distribution, and the angle among implants may affect the accuracy of the implant impression. This study explored factors influencing the accuracy of implant abutment-level digital impressions using stereophotogrammetry in edentulous jaws.

METHODS

Two standard all-on-4 and all-on-6 models of edentulous jaws were constructed in vitro. In the stereophotogrammetry group (PG), the implant digital impression was made using stereophotogrammetry and saved as an STL file. In the conventional group (CNV), the impression was made using the open-tray splint impression technique. An electronic and optical 3D measuring instrument was used to scan the standard model and the conventional plaster model to obtain STL files. Using 3D data processing software (GOM Inspect Pro, Zeiss), the distance and angle between the abutments in the CNV impression and the PG impression were measured and compared with the data from the standard model.

RESULTS

The distance deviation in the PG and the CNV was 145 ± 196 μm and 96 ± 150 μm, respectively, with a significant difference (P < 0.001). The angle deviation in the PG and the CNV was 0.82 ± 0.88° and 0.74 ± 0.62°, respectively, with no significant difference (P = 0.267). In the PG, the distance deviation was negatively correlated with the distance between implants (r = -0.145, P = 0.028) and positively correlated with the angle of implants (r = 0.205, P = 0.002). The angle deviation was negatively correlated with the distance between implants (r = -0.198, P = 0.003) and positively correlated with the angle of implants (r = 0.172, P = 0.009). In the CNV, the effect of inter-implant distance on impression accuracy was also shown by Spearman correlation analysis: r = 0.347 (P < 0.001) for distance deviation and r = -0.012 (P = 0.859) for angle deviation. The effect of inter-implant angulation on impression accuracy deviation was r = -0.026 (P = 0.698) for distance deviation and r = 0.056 (P = 0.399) for angle deviation.

CONCLUSIONS

The CNV method is closer to the real value of the original model. The distance between implants and the distribution angle had a weak correlation with the accuracy of digital impressions but no significant correlation with the accuracy of traditional impressions.

Effect of different implant positions for two implant-retained mandibular overdenture: a retrospective 5-years radiographic evaluation of the circumferential peri-implant bone loss and posterior ridge resorptive changes

BACKGROUND

Studies did not recommend which position for implant overdenture poses the lowest biomechanical risk and the least chance of peri-implant bone loss and ridge resorption for those who might need a mandibular two-implant overdenture. The study objectives were to investigate the impact of implant position, in lateral incisors or canine positions, on peri-implant bone loss and posterior ridge resorption.

METHODS

Fifty patients with mandibular two-implants were recalled and divided according to the implant position into two groups (group L: implants in lateral incisor positions and group C: implants in canine positions). The circumferential peri-implant bone level and posterior ridge resorption were assessed at implant insertion (T0), one year later (T1), and five years later (T5) using the follow-up CBCT. Data were analyzed using the Statistical Package of Social Science (SPSS) program. A Mann-Whitney test was used to compare two different groups. Paired groups were compared using the Wilcoxon signed-rank test. The threshold of significance is fixed at a 5% level (p-value).

RESULTS

Significant differences in the vertical bone loss between groups appeared at (T5 - T1) (Mann Whitney test, (P = 0.01)) and at (T5 - T0) (Mann Whitney test, (P = 0.005)), and a significant difference in horizontal bone loss between groups was found at (T1 - T0) (Mann Whitney test, (P = 0.041)) and (T5 - T1) (Mann Whitney test, (P = 0.041)). Also, there were significant differences over the evaluation period between groups at certain points along the ridge at M1 (Mann Whitney test, (P = 0.021)), M3 (Mann Whitney test, (P = 0.008)), and M4 (Mann Whitney test, (P = 0.015)).

CONCLUSIONS

According to the findings of this clinical study, the placement of implants in the lateral incisor position for two implant-retained overdentures is a viable choice. In comparison to the canine position, the lateral incisor position demonstrated superior peri-implant responses, which could potentially enhance the longevity of the implants. Furthermore, the placement of implants in the lateral incisor position can promote a more even distribution of stress and help mitigate posterior ridge resorption. Conversely, implants in the canine position may cause a seesaw effect and result in greater posterior ridge resorption.

CLINICAL TRIAL REGISTRY NUMBER

(NCT06055842) (13/03/2024).

How far can we go? A 20-year meta-analysis of dental implant survival rates

OBJECTIVE

This meta-analysis aims to investigate the long-term survival rates of dental implants over a 20-year period, providing a practical guide for clinicians while identifying potential areas for future research.

MATERIALS AND METHODS

Data were sourced from recent publications, focusing exclusively on screw-shaped titanium implants with a rough surface. Both retrospective and prospective studies were included to ensure an adequate sample size. A systematic electronic literature search was conducted in the databases: MEDLINE (PubMed), Cochrane, and Web of Science. The risk of bias for all studies was analyzed using a tool by Hoy et al. RESULTS: Three prospective studies (n = 237 implants) revealed a mean implant survival rate of 92% (95% CI: 82% to 97%), decreasing to 78% (95% CI: 74%-82%) after imputation (n = 422 implants). A total of five retrospective studies (n = 1440 implants) showed a survival rate of 88% (95% CI: 78%-94%). Implant failure causes were multifactorial.

CONCLUSION

This review consolidates 20-year dental implant survival data, reflecting a remarkable 4 out of 5 implants success rate. It emphasizes the need for long-term follow-up care, addressing multifactorial implant failure. Prioritizing quality standards is crucial to prevent overestimating treatment effectiveness due to potential statistical errors. While dental implantology boasts reliable therapies, there is still room for improvement, and additional high-quality studies are needed, particularly to evaluate implant success.

CLINICAL RELEVANCE

Never before have the implant survival over 20 years been systematically analyzed in a meta-analysis. Although a long-term survival can be expected, follow-up is essential and shouldn't end after insertion or even after 10 years.

Maxillary and mandibular overdentures retained by two unsplinted narrow-diameter titanium-zirconium implants - A clinical pilot study

OBJECTIVES

To evaluate the survival rates and marginal bone loss of narrow-diameter titanium-zirconium implants supporting complete maxillary and mandibular overdentures up to 3 years after loading.

MATERIALS AND METHODS

Ten completely edentulous patients who were dissatisfied with their complete dentures were enrolled. Two narrow-diameter implants were placed in the canine region of the maxilla and mandible. After second-stage surgery, implant-supported overdentures (palatal-free) attached by parallel alignable stud-attachments were placed. Patients were followed periodically for up to 36 months. Standardized radiographs were taken at baseline, 12 and 36 months to analyze mean marginal bone level changes around the implants.

RESULTS

The Kaplan-Meier survival rates were 100% for mandibular and 68.0% (SE ± 10.9%) for maxillary implants at 36 months (p = .008). Six maxillary implants failed after loading; no mandibular implants were lost. Five implants failed due to loss of osseointegration. One implant fractured. The mean marginal bone level changes around the analyzed implants (n = 28, 9 patients) were -0.71 ± 0.82 mm in the mandible and -2.08 ± 1.52 mm in the maxilla at the 36-month follow-up. The difference in marginal bone level changes between the maxilla and mandible was significant (p = .019) at the 12- and 36-month follow-ups.

CONCLUSION

Two narrow-diameter titanium-zirconium implants with stud-attachments showed a highly satisfactory outcome in the mandible. The maxillary implants showed a high failure rate and significantly more bone loss over time than the mandibular implants. The minimal concept of two implants and an overdenture should be limited to the edentulous mandible.

Hyoid displacement during swallowing function for completely edentulous subjects rehabilitated with mandibular implant retained overdenture

BACKGROUND

Hyoid bone is attached to the mandible, tongue, larynx, temporal bone, and cervical spine via different types of muscles or ligaments. The tongue, mandible, and hyoid system play a crucial role in swallowing function. This within subject study aimed to evaluate the impact of mandibular implant overdentures on the displacement of the hyoid bones during the swallowing process.

METHODS

Twenty five healthy edentulous subjects were selected for participating in the study. New complete dentures were constructed for all the participants. Subsequently two dental implants were inserted in the canine regions of the participant's mandibular arch. In order to retain the mandibular prosthesis in place, ball attachments were incorporated into the mandibular dentures to convert them into implant overdentures. Using 10 ml of thin liquid bolus, videofluoroscopy swallowing examination was performed in three different oral conditions: without complete dentures (WCD), with complete denture (CDs), and with a mandibular implant overdenture (IODs). ANOVA with Bonferroni test was used to analyze the data in order to determine how the hyoid displacement varied throughout different oral conditions.

RESULTS

Compared to complete dentures, mandibular implant overdentures showed a significant decrease (P < 0.05) in both anterior hyoid displacement and duration of hyoid maximum anterior excursion (DOHMAE). However, there was a non-significant difference (P > 0.05) between the two oral circumstances in terms of superior hyoid displacement or duration for hyoid maximum elevation (DOHME). There is no penetration or aspiration for both complete denture and implant overdenture oral conditions.

CONCLUSION

Implant retained overdentures have a positive effect on hyoid displacement during swallowing of thin liquid bolus consistency relative to conventional complete dentures.

TRIAL REGISTRATION

Retrospectively registered (NCT06187181) 02/1/2024.

Single-Piece Implant Systems and its Longterm Stability: An Evaluative Research

Objective

The objective of this research was to compare the longstanding stability of single-piece implant systems to typical two-piece systems by analyzing patient records retrospectively.

Methods

A retrospective examination of patient records from January 2010 to December 2020 was undertaken at the Department of Oral Implantology, University Hospital. The research included dental rehabilitation patients who got single- or two-piece implant systems. Patient demographics, implant features, surgical procedures, and follow-up results were extracted. Implant success rates, stability defined by resonance frequency analysis (RFA) utilizing Osstell ISQ®, and peri-implant bone loss evaluated by standardized periapical radiographs at baseline and follow-up visits were the main outcomes.

Results

The research involved 320 patients (160 per cohort). The average patient age was 52.7 years, with 55% men. The mandibular region received 65% of implants, and the maxillary region the rest. Single-piece cohort A had 94.6% implant success, and two-piece cohort B 96.2%. Implant success rates were similar between cohorts (P = 0.412). The mean ISQ scores were 72.4 ± 4.8 in cohort A and 74.8 ± 5.1 in cohort B (P = 0.086). Peri-implant bone loss was 1.8 ± 0.7 mm in cohort A and 1.4 ± 0.6 mm in cohort B (P = 0.031).

Conclusion

Single-piece implant systems provide a stable and successful alternative to classic two-piece systems. However, patient selection, surgical technique, and monitoring are essential to reduce peri-implant problems and improve clinical results. To improve implant dentistry patient care and evidence-based clinical practice, single-piece and two-piece implant systems' design, biomechanical features, and longstanding performance should be studied.

Identification of the Incisive Branch of the Inferior Alveolar Nerve of Edentulous Mandibles Using Cone-Beam Computerized Tomography

This study explored the average length of the incisive branch (IB) of the inferior alveolar nerve on cone-beam computerized tomography (CBCT) with regard to patient demographics in patients with edentulous mandibles. CBCT was used in a retrospective study of edentulous mandibles to assess the presence and anatomical variation for the IB. Three independent observers measured bilateral IB lengths. In addition to demographics, IB length and port of exit data were obtained. A 1-way analysis of variance was used to test whether IB length varied by sex or port of exit, and a standard Pearson correlation was used to test for IB length and age significance, with a significance level of P < .05. Intraclass correlation coefficients showed significant agreement in IB length across all observers. No significant difference was noted between the exit port and IB length. An important effect was reported for sex, indicating women have generally shorter IB lengths (9.43 ± 3.99 vs 10.55 ± 3.92). There was a significant correlation with age, but the relationship was weak. Edentulous mandibles have an altered anatomic landscape, and establishing predictive IB dimensions aids practitioners in surgical planning.

Clinical and radiographic outcomes around 4 mandibular implant-retained overdentures in individuals with type 2 diabetes: A long-term retrospective study

OBJECTIVES

To report the implant survival rates, clinical, and radiographic status after a period of more than 5 years in the function of 4 inter-foraminal implants retaining mandibular overdentures (OVDs) in individuals with T2DM.

METHODS

78 completely edentulous participants with type 2 diabetic mellitus (T2DM) who had worn mandibular OVDs retained by 4 inter-foraminal implants for long-term functional life were selected for this study. The participants were divided into 2 groups according to glycosylated haemoglobin A1c (HbA1c) levels before implant placement: group I with an HbA1c value > 6.5 % (inadequately controlled T2DM), and group II with an HbA1c value ≤6.5 % (well-controlled T2DM). The inadequately controlled T2DM was further subdivided into 2 groups: Group IA with an HbA1c value > 6.5 % and ≤8 % (moderately controlled), and Group IB has an HbA1c value > 8 % (poorly controlled). Implant survival rate, plaque index (PI), bleeding on probing (BOP), probing depth (PD), and radiographic crestal bone level (CBL) around implants were measured.

RESULTS

Among 312 implants, 6 failed, 4 in well-controlled diabetics, and 2 in inadequately controlled diabetics. The overall survival rate was 98.07 %. The mean PI in group Ι was 36.4 (group IA =37.76, group IB = 34.27), and in group ΙΙ it was 19. The mean BOP in group Ι was 45.5 (group IA =47.84, group IB = 41.76), and in group ΙΙ it was 22. The mean PD in group Ι was 4.1 (group IA =4.3, group IB = 3.85) and in group ΙΙ was 2.2. The mean radiographic CBL in group Ι was 3.4 (group IA =3.7, group IB = 2.9), and in group ΙΙ was 1.5. Group IA exhibited a significantly greater level of PI, BOP, PD, and CBL compared to group IB and group IΙ (P1=0.017, P2=0.001).

CONCLUSIONS

Individuals with T2DM can benefit from 4 inter-foraminal implants retained mandibular OVDs, and their inability to maintain proper glucose control may not exclude implant success.

CLINICAL SIGNIFICANCE

This study is a significant step toward improving knowledge of options available for treatment and anticipated outcomes for T2DM completely edentulous populations undergoing implant therapy.

Effect of auxiliary geometric devices on the accuracy of intraoral scans in full-arch implant-supported rehabilitations: An in vitro study

OBJECTIVES

The aim of the present in vitro study was to evaluate the effect of a novel auxiliary geometric device (AGD) on the accuracy of full-arch scans captured with 3 different intraoral scanners (IOS).

METHODS

An edentulous maxillary model with four internal connection implant replicas was scanned using 3 different IOS: iTero Element 5D (ITERO) (Align Technology, Tempe, AZ, USA), Trios 4 (TRIOS) (3Shape A/S, Copenhagen, Denmark), and Carestream 3700 (CS) (Carestream Dental, Atlanta, USA). Thirty-six scans were taken with each IOS, 18 with the AGD in place, and 18 without the AGD. A digital master model was created using an industrial optical scanner (ATOS compact Scan 5M, GOM GmbH, Braunschweig, Germany). The master and IOS models were aligned using the scan bodies as a reference area. A surface comparison was performed, and deviation labels were exported for each scan body to evaluate the linear and angular deviation. Total body, platform and angular deviations were measured.

RESULTS

The use of AGD resulted in a statistically significant increase of angular deviation: 0.87° (SD=0.21) in the AGD group versus 0.64° (SD=0.46) in the no AGD group (p-value=0.005). The difference between the AGD and no AGD groups was not statistically significant for total body and platform deviation values (p-value=0.051 and 0.302 respectively). Using AGD, ITERO showed a statistically significant increase in angular deviation (mean difference=-0.46 µm, p-value=0.002) and a decrease in mean platform deviation (mean difference=63.19 µm, p-value<0.001). No statistically significant differences were found for the other IOS.

CONCLUSIONS

The use of AGD did not add benefit on CS and TRIOS. On ITERO, there was an improvement in platform deviation, that was outweighed by the worsening of the angular deviation.

CLINICAL SIGNIFICANCE

In vitro data suggest that intraoral scans can be successfully used in full-arch cases. The use of AGD has no additional benefit on CS and TRIOS. On ITERO there was an improvement in platform deviation that was outweighed by the worsening of the angular deviation. Translational application to clinical practice deserves further investigation, taking into account patient-related and anatomical variables.

Long-Term Clinical Outcomes of 3D-Printed Subperiosteal Titanium Implants: A 6-Year Follow-Up

As an alternative to regenerative therapies, numerous authors have recently proposed bringing back subperiosteal implants. The aim of the study was to present our clinical experience with a subperiosteal jaw implant that needs minimal bone preparation and enables the rapid implantation of prosthetic teeth in edentulous, atrophic alveolar bone. The research included 36 complete or partial edentulous patients (61 subperiostal implants) over a period of 6 years. To create the patient-specific subperiostal implants design, DentalCAD 3.0 Galway software (exocad GmbH, Darmstadt, Germany) was used and fabricated with a Mysint 100 (Sisma S.p.A., Piovene Rocchette, Italy) by titanium alloy powder. The results showed that only 9 of the 36 cases were successful at 6-year follow-up, while 27 cases had complications, including exposure of the metal frame (early or delayed), mobility of the device prior to the first 4-6 months, and late mobility due to recurrent infections and progressive structure exposure; 1 case failed for reasons unrelated to the device. This study indicated that the prudent application of fully customized subperiosteal jaw implants is a dependable alternative for the dental rehabilitation of atrophic edentulous cases that necessitate bone grafts for traditional fixed dental implant solutions.

Evaluation of the Impact of Digital Dentistry on the Precision of Implant Placement and Prosthesis Fabrication: An In-Vitro Study

BACKGROUND

Digital dentistry has revolutionized the field of implant dentistry, offering enhanced accuracy and precision in implant placement and prosthesis fabrication. This study aims to evaluate the effect of digital dentistry on the accuracy of implant placement and prosthesis fit through a comprehensive in-vitro assessment.

METHODS

In this in-vitro study, a Digital Dentistry Group and a Conventional Group were compared regarding implant placement accuracy and prosthesis fit. Measurements of coronal deviation, apical deviation, global deviation, angulation deviation, and depth deviation were obtained for implant placement accuracy, while marginal fit and internal fit were assessed for prosthesis fit. Statistical analysis was performed to determine significant differences between the two groups.

RESULTS

The Digital Dentistry Group demonstrated significantly lower values of coronal deviation, apical deviation, global deviation, angulation deviation, and depth deviation compared to the Conventional Group (p < 0.001). Similarly, the Digital Dentistry Group exhibited superior marginal fit and internal fit (p < 0.001) when compared to the Conventional Group.

CONCLUSION

This in-vitro study provides evidence supporting the superior accuracy of implant placement and improved prosthesis fit achieved through digital dentistry techniques. The use of intraoral scanners, computer-aided design/computer-aided manufacturing (CAD/CAM) systems, and three-dimensional (3D) imaging enables precise digital impressions, virtual planning, and custom-made prostheses with superior fit and esthetics. Incorporating digital dentistry into clinical practice can enhance treatment outcomes and patient satisfaction in implant dentistry.

A comparative evaluation of masticatory load distribution in different types of prosthesis with varying number of implants: A FEM analysis

Aim

To identify the optimal number and position of implants to reduce stress concentration on the implant, denture, and attachment system for sustaining an overdenture prosthesis.

Materials and methods

By incorporating one to eight indigenous implants with bar-type attachments, eight 3D finite element models of mandibular overdentures were created. All models received a 200 N vertical load, and the biomechanical characteristics of peri-implant bone were assessed.

Result

The study observed that with a vertical load of 200 N, the maximum equivalent stress around peri-implant tissue in all models was within the physiological tolerance threshold of bone. The von Mises stress values ranged from 116.18 MPa to 536.7 MPa.

Conclusion

The three-implant-supported overdenture model revealed superior peri-implant stress, stability, cost-effectiveness, and hygiene maintenance outcomes. Placing a third implant in the mid-symphysis region may offer a practical solution to reduce rotations in two-implant-supported overdentures.

Computer-assisted preoperative planning system with an automated registration method in prosthesis-driven oral implantology

PURPOSE

Dentition defect including edentulism is a problem that deserves attention, which requires precise preoperative planning. The trajectories of the implants can be determined using a pre-made radiographic template, which is adopted for prosthesis-driven oral implantology. However, existing solutions for the registration between the radiographic template and the patient's CBCT still require manual operation and cause inadequate accuracy. In this study, a pre-operative planning system for prosthesis-driven oral implantology is developed with a novel automated registration method.

METHODS

Based on threshold segmentation and morphological feature filtering, the potential feature points on two sets of CBCTs are, respectively, recognized. The distance features of the point sets are used to predict the optimal solution for point pair matching, after which the automated registration is implemented. The prosthesis-driven planning can be completed according to the results of registration and multi-planar reconstruction. Then, the surgical templates can be designed and fabricated using 3D printing technology based on the planning results and finally used for intra-operative guidance during implant placement.

RESULTS

Verification of the proposed method was conducted on three clinical cases. The mean Fiducial Registration Error of 0.13 ± 0.01mm was achieved with great efficiency. The average time was 0.15 s for the automatic registration algorithm, and 15.64 s for the whole procedure.

CONCLUSIONS

The proposed method proved to be accurate and robust. The results indicate that it can achieve higher efficiency while maintaining a low error level, which will have great potential clinical applications in the future.

Effect of bar designs on peri implant tissues health in implant-supported removable prostheses: a systematic review

Different characteristics of bars (cross-sectional shape, diameter, distal extension etc.) lead to different biomechanical behavior (retention and stress) with implants and peri-implant tissues.Aim: To evaluate the impact of implant-supported removable prostheses bar designs in fully edentulous arch (in the maxilla and/or mandibula), with 4 implants or more, on the peri-implant soft and hard tissues.Two reviewers searched for observational studies, RCT and in vitro studies, published on five main databases and three from the grey literature, without restrictions on November 2023.Of the 3049 selected articles, four met the inclusion criteria. Four RCT evaluated peri-implant health tissues in full edentulous arches with 4 or 6 implants rehabilitated with implant bar overdentures. One prospective study with 5 years follow-up evaluated the success/survival rate of implants and implant bar overdentures. Overall, 261 subjects were enrolled in our systematic review with 1176 implants. Overdentures' survival rate was 100%. There was a trend that plaque indices and gingival indices were low in all of the studies, however no statistical analysis was done due to the lack of information.Due to the lack of information in the included studies, we cannot confirm if bar characteristics affect the peri-implant tissues health.

Survival and Success of Dental Implants in Patients with Autoimmune Diseases: a Systematic Review

Objectives

The purpose of this systematic review is to disclose the impact of autoimmune diseases and their medical treatment on dental implant survival and success.

Material and Methods

A literature search was conducted using MEDLINE (PubMed), The Cochrane Library and Embase up to December 6th, 2021. Any clinical study on patients with an autoimmune disease in whom implant therapy was performed was eligible. The quality of included studies was assessed using the Newcastle-Ottawa Scale. For each autoimmune disease group, data synthesis was divided into three groups: 1) overall results of the autoimmune disease, 2) overall results of corresponding control groups and 3) overall results of the autoimmune disease with a concomitant autoimmune disease (a subgroup of group 1). Descriptive statistics were used.

Results

Of 4,865 identified articles, 67 could be included and mainly comprising case reports and retrospective studies with an overall low quality. Implant survival rate was 50 to 100% on patient and implant level after a weighted mean follow-up of 17.7 to 68.1 months. Implant success was sporadically reported. Data on immunosuppressive medication were too heterogeneously reported to allow detailed analysis.

Conclusions

Overall, a high implant survival rate was reported in patients with autoimmune diseases. However, the identified studies were characterized by a low quality. No conclusions could be made regarding implant success and the effect of immunosuppressants due to heterogeneous reporting.

Advancements in artificial intelligence algorithms for dental implant identification: A systematic review with meta-analysis

STATEMENT OF PROBLEM

The evidence regarding the application of artificial intelligence (AI) in identifying dental implant systems is currently inconclusive. The available studies present varying results and methodologies, making it difficult to draw definitive conclusions.

PURPOSE

The purpose of this systematic review with meta-analysis was to comprehensively analyze and evaluate articles that investigate the application of AI in identifying and classifying dental implant systems.

MATERIAL AND METHODS

An electronic systematic review was conducted across 3 databases: MEDLINE/PubMed, Cochrane, and Scopus. Additionally, a manual search was performed. The inclusion criteria consisted of peer-reviewed studies investigating the accuracy of AI-based diagnostic tools on dental radiographs for identifying and classifying dental implant systems and comparing the results with those obtained by expert judges using manual techniques-the search strategy encompassed articles published until September 2023. The Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool was used to assess the quality of included articles.

RESULTS

Twenty-two eligible articles were included in this review. These articles described the use of AI in detecting dental implants through conventional radiographs. The pooled data showed that dental implant identification had an overall accuracy of 92.56% (range 90.49% to 94.63%). Eleven studies showed a low risk of bias, 6 demonstrated some concern risk, and 5 showed a high risk of bias.

CONCLUSIONS

AI models using panoramic and periapical radiographs can accurately identify and categorize dental implant systems. However, additional well-conducted research is recommended to identify the most common implant systems.

Retrospective analysis of 50,333 implants on implant failure and associated patient-related factors

PURPOSE

The aim of this investigation was to retrospectively evaluate the long-term implant loss rates and to identify associations between implant failure and patient-related factors in a sample of patients who had consecutively received implant therapy in ten dental universities in the United States using a large database.

METHODS

Dental records of adult patients who had attended the dental clinics of the universities contributing data to the BigMouth network between 2011 and 2022 seeking dental therapy were evaluated. Information regarding patients' characteristics including age, gender, ethnicity, race, tobacco use and systemic medical conditions were extracted from patients' files.

RESULTS

A total of 20,842 patients who received 50,333 dental implants over a 12-year period (2011-2022) were included. The mean age of the cohort was 57.50±14.27 years which consisted of 51.8% females, 91.1% non-Hispanic, 66.3% white individuals and 8% tobacco users. In the univariate analysis, ethnicity, race and marijuana use were significantly associated with implant treatment outcome. Race and ethnicity were significantly associated with implant loss in the multivariate analysis. The implant failure rate was estimated to be 2.7% at the patient level and 1.4% at the implant level.

CONCLUSION

Within the limitations of this retrospective study that utilized records of 50,333 dental implants placed in ten institutions contributing data to the BigMouth network, the implant failure rate was estimated to be 2.7% at patient level and 1.4% at implant level. Ethnicity and race were significantly associated with implant failure, while none of the examined systemic conditions were associated with implant loss.

Prosthetic restorative modality in complete edentulism and its association with masticatory and speech discomforts: A nationwide cross-sectional study from Korea

Purpose Completely edentulous arches can be restored using various prosthetic modalities, and the treatment outcome may include masticatory and speech discomforts. This study aimed to investigate the current status of prosthetic restoration modalities used for completely edentulous patients and investigate the association between prosthetic restoration modalities and subjective discomfort in mastication and speech by analyzing nationwide big data.Methods Of 97,622 individuals, data from 1,576 adults aged ≥40 years with no natural teeth and no requirement for 
additional prosthetic treatments were included. Oral examination data were analyzed, and the prostheses of the edentulous arches were categorized as follows: CD, removable complete denture; OD, implant-retained overdenture; and IF, implant-supported fixed dental prosthesis. Discomforts in mastication and speech according to the prosthetic restorative modality groups was statistically analyzed using analysis of covariance (α = 0.05).Results The maxillary/mandibular prosthetic restorative modality most commonly used was CD/CD, followed by CD/OD, IF/IF, OD/OD, and CD/IF, with weighted percentages of 93.23%, 2.48%, 1.83%, 1.46%, and 0.84%, respectively. Even after adjusting for various covariates, masticatory discomfort in the CD/CD group was significantly greater than that in the OD/OD (P = 0.0004) and IF/IF (P = 0.0002). The CD/CD group also had significantly greater discomfort in speech than did the IF/IF group (P = 0.0119).Conclusions Most completely edentulous patients were rehabilitated with bimaxillary removable complete dentures; however, the discomforts in mastication and speech were the lowest when both arches were restored with implant-supported fixed restorations.

Use of Individually Designed CAD/CAM Suprastructures for Dental Reconstruction in Patients with Cleft Lip and Palate

This patient series reports the outcomes of CAD/CAM prosthetic reconstructions in patients with cleft lip and palate (n = 9, aged 27 to 76) who have experienced significant failure with conventional restorative and fixed prosthodontic treatments. The objective of the protocol is to establish a functional and patient-friendly prosthetic structure for individuals with unilateral/bilateral cleft lip and palate (UCLP/BCLP) while minimising the requirement for specialised follow-up care in the cleft unit. The study data were obtained from a retrospective cohort at Helsinki University Hospital. Prosthetic reconstructions were performed using CAD/CAM bar structures by the Atlantis 2in1 system or Createch removable telescope structures, supported by four to eight maxillary dental implants. Out of the nine patients, seven experienced no complications. One prosthesis fracture occurred after 16 months due to a design error in the original framework, and one patient experienced failure of osseointegration in a dental fixture (specifically, one fixture out of the eight maxillary implants in this patient). In total, 56 implants were successfully placed. The maxillary dentition of elderly patients with cleft lip and palate often poses challenges due to periodontal and reconstructive issues. An implant-supported CAD/CAM bar with a removable telescope suprastructure offers an easily maintained and functional solution for dental rehabilitation.

Reliability of Cone Beam Computed Tomography in Predicting Implant Treatment Outcomes in Edentulous Patients

Since the development of CBCT has been utilized in dentistry, the images of the CBCT can assist the surgeon to evaluate the anatomy carefully. Despite the value of radiology evaluation, implant procedures may require additional consideration rather than only evaluating the anatomical factors. The purpose of this study is to evaluate the predictability of using CBCT alone to plan for implant placement in edentulous patients digitally. CBCT images were analyzed by clinicians, measuring the maxillary and mandibular ridge heights and widths digitally of four predetermined implant sites in the maxillary and two selected implant sites in the mandibular arches of 91 patients planning for implant-supported overdenture. A total of 47 patients out of the 91 had completed implant placement on the edentulous ridge, contributing to 55 upper and/or lower arches (136 dental implants). Both predictabilities are low, implying that CBCT planning for implant placement on the edentulous ridge is not a good index and is insufficient to predict the surgical procedures as a solo method. The findings of this study indicate that digital planning by CBCT is insufficient to serve as an individual tool to predict implant procedures. Further information and evaluation must be considered for implant placement in the edentulous ridge.

A fully digital protocol to provide a fixed interim complete denture for immediate loading for a completely edentulous patient: A dental technique

Complete arch immediate-loading implant-supported prostheses can represent a major challenge for the patient and the dental team. Obtaining stable references and an accurate occlusal record after implant placement to provide an interim prosthesis is a difficult task and can deviate from the initial treatment plan. The described technique presents a fully digital protocol to provide an immediate complete arch implant-supported fixed interim prosthesis for edentulous patients by making postoperative cone beam computed tomography and intraoral digital scans that correlate with the previous plan.

Comparison of the Quality of Life Among the Immediate Loading Implant Overdentures Using the Single and the Double Implants: An Original Study

Introduction

In edentulous individuals, single implant-retained mandibular overdentures are an effective substitute for double implant-retained overdentures. In this current research, the oral health-related quality of life (OHRQoL) was assessed for the immediate loading overdenture using the implants. The comparisons are drawn between the single and double implants.

Materials and Methods

Forty subjects received single and double implants for the placement of the mandibular overdentures. Within a week days of implant insertion, they were loaded with overdentures. Using the Oral Health Impact Profile-14 (OHIP-14) questionnaire, the OHRQoL was measured before treatment, one month following treatment, and 12 months thereafter.

Results

In both the single implant and double implant groups, participants' mean OHIP-14 scores decreased statistically significantly for the different timelines. For the single implant group, the baseline total mean OHIP-14 score was 14.33, and for double implants, it was 19.15. Following therapy, it decreased to 8.55 in the single implant group and 9.48 for the double implant group at one month, and at 12 months, it further decreased to 3.25 in the single implant group while it was 5.15 in the double implant group.

Conclusions

Single and double implants increase the QoL for older subjects who are edentulous at the 1-month and 1-year recall points. When two implants are used by older individuals, the single implant might offer an equivalent quality of life.

The Single Midline Implant in the Edentulous Mandible-Current Status of Clinical Trials

The single midline implant in the edentulous mandible is a treatment concept that has often been controversially discussed. Nearly 30 years ago, the first available clinical results revealed high implant survival rates and remarkable improvements in oral comfort, function, patient satisfaction and oral health-related quality of life for edentulous patients compared to the situation with no implant. However, the clinical trials were predominantly conducted with a small number of patients over a short to medium follow-up period. Today, numerous clinical investigations on the single midline implant in the edentulous mandible, which increasingly include longer-term observation periods, are available. It is the aim of this overview to present the current literature and to highlight the clinical problems. This article is a 2023 update of a review published by the authors in the German language in 2021 in the German journal Implantologie. In total, 19 prospective clinical trials with a follow-up period of 0.5-10 years were analyzed. Over this observation period, single implants with modern rough implant surfaces in the edentulous mandible reveal high implant survival rates of between 90.9 and 100% when a conventional delayed loading protocol was applied.

Dental implant macrodesign features in the past 10 years: A systematic review

Dental implant is a material used in replacing missing teeth. The osseointegration process of dental implants will be affected by the macrodesign of the fixtures. This study aimed to review the dental implant macrodesign in the past 10 years. This study was conducted in a systematic review method using two electronic databases (PUBMED and Science Direct). Only randomized controlled trials (RCTs) published in the last 10 years were used for this review. All the search results were filtered using Preferred Reporting Items for Systematic Reviews And Meta-Analyses and should fulfill some predefined inclusion criteria. The last step was to assess the methodological quality of the studies using the JBI Checklist for RCT. The search identified 357 studies with only 23 that going through full-text analysis, resulting in 14 articles included in the review. In total, 19 different implant brands were used in 12 different countries. Dental implant macrodesigns were divided into collar design, implant shape, thread geometry, and platform design. The macrodesign features of the implant were mostly developed in the variation of thread geometry and collar design.

Effect of crown stiffness and prosthetic screw absence on the stress distribution in implant-supported restoration: A 3D finite element analysis

This in-silico investigation evaluated the mechanical impact of Morse tape implant-abutment interface and retention system (with and without screw) and restorative materials (composite block and monolithic zirconia) by means of a three-dimensional finite element analysis (3D-FEA). Four 3D models were designed for the lower first molar. A dental implant (4.5 × 10 mm B&B Dental Implant Company) was digitized (micro CT) and exported to computer-aided design (CAD) software. Non-uniform rational B-spline surfaces were reconstructed, generating a 3D volumetric model. Four different models were generated with the same Morse-type connection, but with a different locking system (with and without active screw) and a different crown material made of composite block and zirconia. The D2 bone type, which contains cortical and trabecular tissues, was designed using data from the database. The implants were juxtaposed inside the model after Boolean subtraction. Implant placement depth was simulated for the implant model precisely at crestal bone level. Each acquired model was then imported into the finite element analysis (FEA) software as STEP files. The Von Mises equivalent strains were calculated for the peri-implant bone and the Von Mises stress for the prosthetic structures. The highest strain values in bone tissue occurred in the peri-implant bone interface and were comparable in the four implant models (8.2918e-004-8.6622e-004 mm/mm). The stress peak in the zirconia crown (64.4 MPa) was higher than in the composite crown (52.2 MPa) regardless of the presence of the prosthetic screw. The abutment showed the lowest stress peaks (99.71-92.28 MPa) when the screw was present (126.63-114.25 MPa). Based on this linear analysis, it is suggested that the absence of prosthetic screw increases the stress inside the abutment and implant, without effect on the crown and around the bone tissue. Stiffer crowns concentrate more stress on its structure, reducing the amount of stress on the abutment.

Clinical outcomes of different implant types in mandibular bar-retained overdentures: a retrospective analysis with up to 20 years follow-up

PURPOSE

To determine the clinical and radiological outcomes of hybrid-design- (HD) and bone-level (BL) implants for bar-retained mandibular implant-overdentures (IODs).

METHODS

For this retrospective study, edentulous patients who had received maxillary complete dentures and mandibular bar-retained IODs were invited for a follow-up assessment. Implant survival, implant success and health of peri-implant tissues were assessed on an implant level-based analysis. Patient-based parameters served to identify risk factors for peri-implant bone loss, presence of peri-implantitis and success.

RESULTS

Eighty patients (median age 72.72 [67.03; 78.81] years, 46 females) with 180 implants (median follow-up 12.01 [10.82; 21.04] years) were assessed. There was no difference concerning the rate of implant failure (p = 0.26), or peri-implantitis (p = 0.97) between HD and BL implants. Solely in one study group, there was the presence of peri-implant pus. Implant success was higher in BL implants with one group being notably higher than the comparing groups (p = 0.045). For bone loss, a width of keratinized mucosa (KM) ≤ 1 mm (p = 0.0006) and the presence of xerostomia (p = 0.09) were identified as risk factors. Smoking (p = 0.013) and a higher body mass index (BMI) (p = 0.03) were a risk factor for peri-implantitis. As risk factors for reduced implant success, a small width of KM (p = 0.003) and the presence of xerostomia (p = 0.007) were identified.

CONCLUSIONS

For mandibular bar-retained IODs, both BL and HD implants are mostly successful. A minimum of 1 mm KM around implants and normal salivary flow are relevant factors for implant success and stable peri-implant bone levels. Smoking and a high BMI are potential risk factors for peri-implantitis.

Survival Rates and Clinical Outcomes of Implant Overdentures in Old and Medically Compromised Patients

Studies on the survival rate of implant overdentures in medically compromised patients are limited because most studies exclude patients with systemic diseases affecting implant prognosis. This retrospective study aimed to evaluate the survival rate and clinical outcomes of dental implants used for overdentures in medically compromised patients. A total of 20 patients (9 men, 11 women; mean age: 67.55 ± 6.84 years, range: 53-81 years) were included. Fourteen patients had more than two systemic diseases, and nine patients had more than three systemic diseases. The mean follow-up period was 39.05 months. Of the 60 implants, 2 failed, resulting in an implant survival rate of 96.6%. No statistical differences were found in implant survival rates according to sex, age, implant diameter, restored arch, or opposing dentition (p > 0.05). A significant difference in mean marginal bone loss (MBL) was noted for restoring the arch (p = 0.022) and opposing dentition (p = 0.036). Implants placed in the mandible and with opposing removable partial dentures and complete dentures showed lower mean MBL. No significant differences in implant MBL were observed in terms of age, sex, or implant diameter (p > 0.05). Favorable clinical outcomes can be expected from implant overdentures using two or four implants in edentulous patients with systemic diseases by ensuring that the patients have a sufficient healing period and regular checkups.

Survival of conventional dental implants in the edentulous atrophic maxilla in combination with zygomatic implants: a 20-year retrospective study

PURPOSE

Implant-supported prosthetic rehabilitation in the resorbed maxilla is a great challenge. The aim of this study was to determine the survival rate of conventional anterior implants placed in combination with zygomatic implants according to the Brånemark technique, and to identify risk factors for implant failure.

METHODS

We collected data retrospectively from 72 consecutive patients who received treatment from 1998 to 2018 at our center, according to Brånemark's original technique. Kaplan-Meier analysis was conducted to assess survival rate, and a survival regression model was used with the patient as the random factor, applying the Weibull distribution.

RESULTS

A total of 236 maxillary anterior implants were included, with a mean follow-up of 12.1 years. Kaplan-Meier analysis showed overall cumulative survival rates of 95.3% at 1 year, 94.8% at 2 years, 93.0% at 5 years, 90.5% at 10 years, 81.6% at 15 years, and 67.7% at 20 years. Survival regression showed an association between bruxism and implant failure as well as implants bearing an overdenture. Implants with length ≤ 10 mm had a significantly lower survival time. No significant association was found between the number of anterior implants and survival rate.

CONCLUSIONS

We found acceptable long-term anterior conventional implant survival. Significant risk factors for failure were bruxism, overdentures, and implants shorter than 10 mm.

Unsplinted Attachments and Patient-Reported Outcome Measures (PROMs) in 2-Implant-Retained Mandibular Overdentures: A Systematic Review

Introduction

The purpose of this review is to compare randomized clinical trials evaluating the patient-reported outcome measures (PROMs) using different unsplinted attachment systems in 2-implant-retained mandibular overdentures (2IRMODs). A focus question (as per PICOS) was set as follows: does one particular unsplinted attachment system (I) compared with another (C) result in better patient-reported outcomes (O) in two-implant-retained mandibular overdentures (P) using randomized controlled trials (S)?

Materials and Methods

A literature search was conducted in the PubMed MEDLINE and Cochrane Central Register of Controlled Trials (CENTRAL) databases between November 2010 and October 2020. Only randomized controlled trials (RCTs) on 2IRMOD using unsplinted attachment systems measuring patient-centered outcomes were selected. A total of 171 studies were identified in initial search, and 27 studies were shortlisted for full-text evaluation. A total of 5 studies were included for a systematic review. The risk of bias was evaluated using Cochrane Risk of Bias Tool 2.0 (RoB 2.0). Meta-analysis could not be performed as different studies evaluated different patient-reported outcomes, namely, satisfaction, quality of life, complications, preferences, or combinations of these.

Results

A total of 23 patients received low-profile (self-aligning) attachments (in 2 studies), 69 patients received standard ball attachments (in 5 studies), 25 patients received telescopic (or conus) attachments (in 2 studies), and 20 patients received mini-ball attachments (in 1 study). Two studies compared ball attachments and low-profile attachments and revealed similar satisfaction and quality of life (QoL). Two studies compared ball attachments with telescopic attachments and revealed less patient satisfaction in telescopic attachments. A single study compared mini-ball attachments with standard ball attachments and showed no difference in patient-reported outcomes. Three studies were found to have a low risk of bias, and the remaining two studies had a high risk of bias.

Conclusions

The standard ball, mini-ball, and low-profile attachments have no influence on PROMs in the normal interarch space. Inconclusive results were found in studies that evaluated PROMs using ball attachments versus telescopic attachments.

Biomechanical variables affect peri-implant bone loss in implant-supported fixed complete dentures: a methodological and prospective study

PURPOSE

Implant-supported fixed complete dentures (IFCD) experience failures and complications related to biological and technical risk factors. This study investigated the effect of biomechanical variables of IFCD on 1-year peri-implant bone loss at the buccal, palatal/lingual, mesial, and distal implant sides. A new method was used to measure the geometric biomechanical variables of IFCD using cone beam computed tomography (CBCT).

METHODS

The study sample consisted of 246 external hexagon implants supporting 48 hybrid IFCD in 44 patients. CBCT images obtained immediately (T0) and 1 year (T1) after prosthesis installation were used to measure the support polygon area, clinical crown/implant (C/I) ratio (vertical lever), anteroposterior power and resistance arms, anterior and posterior cantilevers (horizontal levers), and peri-implant bone remodeling (T1-T0). Data were analyzed using multilevel multivariable models.

RESULTS

The average total bone loss in the mandible and maxilla were 0.88 mm, with a loss of 0.62 mm in the mandible and 1.08 mm in the maxilla. The C/I ratio had a significant effect on bone loss on the mesial, distal, and palatal/lingual sides (P <.05). The anterior cantilever had a protective effect on the lingual side of the anterior implant. No effect on bone loss was found for the support polygon area, posterior cantilever, resistance arm, or power arm (P >.05).

CONCLUSIONS

The results suggest that the C/I ratio and anterior cantilever in IFCD affect peri-implant bone loss according to the implant side and position in the arch.

Probing combinational influence of design variables on bone biomechanical response around dental implant-supported fixed prosthesis

This study aimed to understand the effect of physiological and dental implant-related parameter variations on the osseointegration for an implant-supported fixed prosthesis. Eight design factors were considered (implant shape, diameter, and length; thread pitch, depth, and profile; cantilever [CL] length and implant-loading protocol). Total 36 implantation scenarios were simulated using finite element method based on Taguchi L₃₆ orthogonal array. Three patient-specific bone conditions were also simulated by scaling the density and Young's modulus of a mandible sample to mimic weak, normal, and strong bones. Taguchi method was employed to determine the significance of each design factor in controlling the peri-implant cortical bone microstrain. For normal bone condition, CL length had the maximum contribution (28%) followed by implant diameter (18%), thread pitch (14%), implant length (8%), and thread profile (5%). For strong bone condition, CL and implant diameter had equal contribution (32%) followed by thread pitch (7%) and implant length (5%). For weak bone condition, implant diameter had the highest contribution (31%) followed by CL length (30%), thread pitch (11%) and implant length (8%). The presence of distal CL in dental framework was found to be the most influential design factor, which can cause high strain in the cervical cortical bone. It was seen that implant diameter had more effect compared to implant length toward peri-implant bone biomechanical response. Implant-loading time had no significant effect towards peri-implant bone biomechanical response, signifying immediate loading is possible with sufficient mechanical retention.

Implant failure rate and the prevalence of associated risk factors: a 6-year retrospective observational survey

Introduction: The purpose of this monocentric retrospective observational investigation is to evaluate the implant failure rate observed in an oral surgery department and analyze the risk factors associated with them. Preventative measures will be suggested to reduce the incidence of implant failure. Material and method: All implants removed between 2014 and 2020 were analyzed. The main criterion assessed was the overall failure rate over 6 years of activity;the secondary criteria were the risk factors associated with implant failure. Results: 12 out of 376 implants placed between 2014 and 2019 in 11 patients (mean age: 55.5 ±11.5 years);sex ratio M/F=5/6) were removed, for an overall failure rate of 3.11%. The majority, 83% (10/12) of the lost implants, were in the maxilla, while only 17% (2/12) were placed in the mandible. The main risk factors identified were: a III−IV bone type density (75%, 9/12), pre-implant sinus lift surgery (42%, 5/12) smoking (8.3%, 1/12), surgical site infection (8.3%, 1/12) and rheumatoid arthritis (8.3%, 1/12). Conclusion: The failure rate observed in this oral surgery unit is consistent with the other international studies, confirming the compliance with good clinical practices of the healthcare team. Pre-implant bone surgery is the major risk factor to consider before implant surgery.

A comparative evaluation of stress distribution between an All-on-Four implant-supported prosthesis and the Trefoil implant-supported prosthesis: A three-dimensional finite element analysis study

Aim

The primary aim of this study is to analyse the stress distribution between an ALL ON FOUR implant supported prosthesis and the TREFOIL implant supported prosthesis with 3D finite element models.

Settings and Design

An in vitro perspective.

Materials and Methods

Two mandibular three-dimensional Finite Element Models were constructed by the CREO version 5 software, in which Model A depicts a mandible with ALL ON FOUR implant supported prost hesis and Model B will depict TREFOIL implant supported prosthesis. Model A contains four implants, two anterior straight and posterior tilted implants (30°), a bar and denture containing acrylic teeth. In Model B, it contains three straight implants and a prefabricated compensatory bar with standardised dimensions. To evaluate and compare the stress distribution between the bone and implant interface, one deleterious cantilever load of upto 300 N is applied on the second molar bilaterally and simultaneously. Another full bite biting load of 150 N is given bilaterally and simultaneously on the central groove of premolars and molars.

Statistical Analysis Used

The results of the simulations obtained were analysed in terms of Von Mises equivalent stress levels at the bone -implant interface.

Results

The results of loading 1 showed that the maximum Von Mises stress was recorded in the anterior implant region of the Trefoil system (Model B) when compared to All on four concept. The results of loading 2 showed that the maximum Von Mises stress were recorded in the anterior implant region Trefoil system (Model B) when compared to All on four concept.

Conclusion

This invitro study concludes that All on Four implant supported prosthesis showed better stress distribution when compared to the Trefoil concept.

Clinical performance of tooth implant-supported removable partial dentures: a systematic review and meta-analysis

OBJECTIVE

To assess the clinical performance of tooth implant-supported removable partial dentures in terms of abutment survival in relation to the attachment system used.

METHODS

An electronic search in MEDLINE/PubMed Web of Science and Cochrane Central Register of Controlled Trials databases was performed. The methodological quality of the studies was assessed using the Newcastle-Ottawa Scale. Survival rates after 3 years and 5 years, loss, and complication rates per 100 years were estimated by Poisson regression.

RESULTS

A total of twelve studies were included; eleven studies were used for the meta-analysis. Survival analysis for mixed attachments showed an estimated survival rate of 100% after 3 years and 5 years. For uniform attachments, the estimated survival rate was 99.3% after 3 years and 98.8% after 5 years. Tooth abutment survival analysis for mixed attachments estimated a survival rate of 95% after 3 years and 91.7% after 5 years: Uniform attachments reached a survival rate of 97.2% after 3 years and 95.4% after 5 years. The prosthetic survival rate was 100% for mixed and uniform abutments after 3 years and 5 years of function.

CONCLUSIONS

Tooth implant-supported removable partial dentures can be considered as a reliable option with excellent prosthetic and implant survival rates and favorable rates for the abutments after 3-year and 5-year follow-ups. Complications may be reduced when 5 or more abutments are used.

CLINICAL RELEVANCE

Tooth implant-supported removable partial dentures are a favorable and potential alternative to restore a partially edentulous arch by optimizing the number and distribution of abutments.

Oral health-related quality of life of patients using single or two-implant mandibular overdentures with immediate loading protocols: A randomized controlled trial

Aim:

Single implant-retained mandibular overdentures (1IMO) is a viable alternative to 2 implant-retained overdentures (2IMO) in edentulous patients. However, literature lacks in the quality of life (QoL) of these patients when treated with immediate loading protocols. The purpose of this study was to compare oral health-related QoL (OHRQoL) of patients using 1IMO or 2 IMO with immediate loading protocols at 1 month and 1 year.

Settings and Design:

Randomized Controlled Trial.

Materials and Methods:

Fifty-two edentulous participants treated with mandibular overdentures using either single implant (n = 26) or two implants (n = 26) with immediate loading protocol by a single operator. The low-profile stud-attachments (LOCATOR; Zest Anchors) were attached to the implants and female attachments were picked up within 0–7 days of implant placement. The OHRQoL was recorded using Oral Health Impact Profile-14 (OHIP-14) questionnaire either in English or in the Malay language before treatment and 1 month and 1 year after treatment.

Statistical Analysis Used:

Kruskal Wallis test was used to find out significant difference amongst 3 timepoints and 7 OHIP-14 domains and Mann-Whitney-U test to compare 1IMO or 2IMO groups.

Results:

Compared to baseline OHIP-14 scores, participants had a statistically significant decrease in total OHIP-14 at 1 month and 1 year after-treatment time points in both 1IMO and 2IMO groups (P < 0.05). The difference between 1 month and 1 year after-treatment total and subscale scores were also found to be statistically significant (P < 0.05). The overall QoL improvement was comparatively higher in 2IMO group than 1IMO group. The OHIP-14 scores were statistically different within seven domains (P < 0.05). Overall total scores between 1IMO and 2IMO groups were also found to be statistically significant (P < 0.05) at baseline and insignificant (P > 0.05) at 1 month and 1 year.

Conclusions:

Mandibular single and 2IMO improve the QoL of elderly edentulous Malaysian participants at 1 month of immediate loading and 1 year of recall. 1IMO may provide comparable QoL with the elderly patients using 2 implants.

Immediately loaded implants simultaneously placed in fresh extraction and healed sites supporting four-implant-supported fixed mandibular prostheses using the all-on-4 concept: A 5-year prospective study

OBJECTIVES

To evaluate the peri-implant marginal bone level for immediately loaded implants placed simultaneously in both fresh extraction sites (FES) and healed sites (HS) supporting a 4-implant supported mandibular fixed prosthesis (4-ISFMP) using the all-on-4 concept.

MATERIAL AND METHODS

A 5-year prospective study was conducted in 24 patients (96 implants) treated with 4-ISFMP including 55 implants inserted in FES and 41 implants in HS. At implant placement (baseline) and at the 1^st -, 3^rd - and 5^th -year follow-up examinations, peri-implant marginal bone level was evaluated radiographically and compared between placement in FES and HS. Marginal bone loss was calculated as the difference in the marginal bone level evaluated at the follow-up periods. Additionally, implant and prosthesis survival rates as well as the presence of peri-implant mucositis (bleeding on probing+[BOP]) and peri-implantitis (BOP+ >2 mm MBL) were evaluated.

RESULTS

22/24 patients with 88/96 implants (dropout rate: 8.3%) were continually followed for 5 years (survival rate: 100%). Radiographically measured marginal bone level differed significantly between FES and HS at implant placement (1.46 ± 0.80 mm vs. 0.60 ± 0.70 mm; p < .001), at the 1-year (-0.04 ± 0.14 mm vs. -0.18 ± 0.20 mm; p = .002) and 3-year (-0.26 ± 0.49 mm vs. -0.58 ± 0.48 mm, p = .049), but not at the 5-year evaluation (-0.90 ± 0.66 mm vs. -1.00 ± 0.59 mm, p = .361). The marginal bone loss differed significantly (p < .001) between FES and HS between implant placement and the 1-year evaluation but not for the 1- to 3-year (p > .99) and the 3- to 5-year period (p = .082). At the 5-year follow-up evaluation, no implant/prosthesis failed (100% survival) and peri-implant mucositis and peri-implantitis were noted in 41.2% and 11.7% at patient level and in 17.6% and 4.5% at implant level respectively.

CONCLUSION

Implants placed in FES showed a prolonged peri-implant remodelling process but provided for similar peri-implant marginal bone levels as implants placed in HS at the 5-year evaluation for immediately loaded 4-ISFMP.

Efficacy of tooth-supported compared to implant-supported full-arch removable prostheses in patients with terminal dentition. A systematic review

AIMS

To compare tooth- (TSRP) and implant-supported (ISRP) removable prostheses in terms of abutment and prosthesis survival (PICO 1) and estimated cumulative survival of teeth/implants and prostheses (PICO 2) at ≥12-month post-prosthesis delivery in patients with stage IV periodontitis.

MATERIALS AND METHODS

Five databases were searched to identify RCTs, CCTs, single arms, prospective cohort studies, case series and retrospective studies. Duplicate screening was performed, and ranges for abutment and prosthesis survival were calculated.

RESULTS

Twenty-six studies were included in the qualitative assessment. Only one study with critical risk of bias comparing the two treatment modalities reported similar survival rates at 2 years. Overall, prospective studies on ISRPs indicated an implant survival rate ranging from 96.4% to 100% and a prosthesis survival rate of 100% with a follow-up from 12 to 54 months. Prospective studies on TSRPs indicated a tooth survival ranging from 85.71% to 100% at 1- to 10-years follow-up.

CONCLUSIONS

The available evidence is of poor quality, and it does not allow to make robust conclusions on the efficacy of these rehabilitations in stage IV periodontitis patients. Particularly for TSRPs, careful patient selection is crucial and a certain number of biological and prosthetic complications should be expected.

Efficacy of rehabilitation with different approaches of implant-supported full-arch prosthetic designs: A systematic review

AIM

To evaluate the efficacy of different types of rehabilitation with fixed or removable full-arch implant-supported prosthesis designs in terms of implant loss and success in patients with at least one edentulous jaw, with tooth loss mainly due to periodontitis.

MATERIALS AND METHODS

Clinical studies with at least 12 months reporting on implant loss and implant success were searched. Meta-analysis was conducted to estimate cumulative implant loss considering different prostheses designs.

RESULTS

A total of 11 studies with unclear to low risk of bias were included in the analysis. Estimated cumulative implant loss for fixed prostheses within 1 year and 5 years was 0.64% (95% confidence interval [CI]: 0.31%-1.31%) and 1.85% (95% CI: 0.85%-3.95%), respectively. The corresponding values for removable prostheses amounted to 0.71% (95% CI: 0.22%-2.28%) and 4.45% (95% CI: 2.48%-7.85%). Peri-implantitis affected 10%-50% of the patients restored with implant-supported fixed prostheses.

CONCLUSIONS

Based on the limited low-quality data, the present analysis points to a low and similar cumulative implant loss within 1 year for patients with tooth loss mainly due to stage IV periodontitis restored with either removable or fixed implant-supported full-arch prosthesis. At 5 years of functioning, there was a tendency for better outcomes using fixed designs.

Immediate Restoration of Single-Piece Zirconia Implants: A Prospective Case Series-Long-Term Results after 11 Years of Clinical Function

OBJECTIVES

The aim of this prospective case series was to evaluate single-piece zirconia implants restored with lithium disilicate CAD/CAM crowns through a long-term follow-up.

METHODS

In this trial, 20 one-piece zirconia implants were placed in 20 patients. Implants were restored (i) immediately with lithium disilicate CAD/CAM provisionals, and (ii) permanently four months after surgery. Patients were followed for 11 years. Clinical parameters and radiological measurements of the zirconia implants were assessed. For the statistical analysis, paired t-test was applied.

RESULTS

Four implants were counted as implant failure due to the loss of implant stability, resulting in a Kaplan-Meier survival rate of 80% up to 11 years. The mean bleeding on probing values were 19.1% (SD ± 13.1) and 18.2% (SD ± 17.6) 96 and 11 years after implant placement, respectively. The plaque index revealed a significant decrease over time (p < 0.001) with a value between 25.9% (SD ± 5.7) and 12.6% (SD ± 10.0) at baseline and 11-years follow-up respectively. The marginal bone level revealed a significant decrease 4, 8, and 11 years after implant insertion (p = 0.001, p = 0.019, and p = 0.027, respectively).

CONCLUSIONS

Immediately loaded zirconia single-piece implants showed a suitable success rate in clinical and radiographic outcomes.

Implant Survival in Immediately Loaded Full-Arch Rehabilitations Following an Anatomical Classification System-A Retrospective Study in 1200 Edentulous Jaws

This retrospective study analyzed implant survival of immediate implant-supported fixed complete denture (IFCD) treatment options (TOs) based on the level of alveolar atrophy (CC). Records of 882 patients receiving a total of 6042 implants at one private referral clinic between 2004 and 2020 were considered. The mean follow-up period was 3.8 ± 2.7 years. Cumulative implant survival rates (CSRs) were analyzed as a function of CCs and TOs according to Mantel-Haenszel and Mantel-Cox. Hazard risk ratios for implant loss were compared using Cox regression. Confounding factors were identified using mixed Cox regression models. The 2- and 5-year CSRs were 98.2% and 97.9%, respectively. Maxillary 2- and 5-year CSRs were lower (97.7% and 97.3%) compared to mandibular CSRs (99.8% and 98.6%) (p = 0.030 and 0.0020, respectively). The CC did not influence CSRs of IFCDs in the mandible (p = 0.1483 and 0.3014, respectively) but only in the maxilla (p = 0.0147 and 0.0111), where CSRs decreased with increasing atrophy. TOs did not statistically differ in terms of survival rate for a given level of alveolar atrophy. The adaption of IFCD treatments to the level of atrophy and patient-specific risk factors can result in high CSRs, even at different levels of bone atrophy.

Maxillary implant overdentures on two or four implants. A prospective randomized cross-over clinical trial of implant and denture success and survival

OBJECTIVES

To determine implant survival and success of four conventionally but initially asynchronously loaded implants in implant-supported overdentures for the edentulous maxilla, in participants with opposing mandibular two-implant overdentures.

MATERIAL AND METHODS

Twenty-six participants received four implants in the region of the maxillary canines and molars. After healing, 24 of these participants (mean age: 68.3 years) were randomly allocated to one of two treatment groups, and the adapted overdenture was attached to two unsplinted cylindrical attachments. The other two matrixes remained unattached to the implants for 3 months. After this period, the other two implants were loaded for 3 months (cross-over design). Then, all four implants were loaded for another 3 months. Kaplan-Meier curves were used to evaluate survival and success of implants and dentures.

RESULTS

During the active prosthetic study phase, three participants lost one implant. Two participants lost three implants during the recall period. Implant survival after loading was 93.8% after a mean observation period of 3.1 years. Denture survival was 100%, but denture success was 95.8%, due to major prosthetic complications. Most participants preferred four implants to two.

CONCLUSIONS

Within the limitations of the study, it can be concluded that maxillary implant overdentures on two or four implants are both recommendable treatment options. Two posterior implants are not superior to two anterior implants under overdentures retained by unsplinted cylindrical attachments. Implant and prosthetic complications and aftercare measures are common but are mostly easy to handle. However, 23 of the 24 participants preferred the 4-implant maxillary overdenture.

Trueness and marginal fit of implant-supported complete-arch fixed prosthesis frameworks made of high-performance polymers and titanium: An explorative in-vitro study

PURPOSE

To investigate the trueness and marginal fit of computer-aided design-computer-aided manufactured (CAD-CAM) complete-arch implant-supported screw-retained fixed prosthesis (CAISFP) made of polyetheretherketone (PEEK), polyetherketoneketone (PEKK) and titanium (Ti) MATERIAL AND METHODS: A typodont model with four implants, their multiunit abutments (MUAs), and MUA scanbodies were digitized by using a laboratory scanner. The generated CAD was used to mill CAISFP frameworks in Ti, PEEK, or PEKK (each n = 10). The frameworks were digitized with an industrial light scanner to superimpose resulting standard tessellation language (STL) file with the CAD file. Deviations at five points at the abutment-framework interface of each of the four abutment sites (1:left first molar, 2:left canine, 3:right canine, 4:right first molar sites) were calculated (trueness). Marginal gaps were measured using the triple scan technique. A nonparametric repeated measures ANOVA by Brunner and Puri with factors being abutment location and material was performed to assess the mean deviations for trueness and mean marginal gaps, followed by Mann-Whitney or exact Wilcoxon Signed-Rank tests (alpha=.05).

RESULTS

Material type significantly affected the trueness (p<0.0001). PEEK had the lowest deviations (0.039 +/-0.01mm) followed by PEKK (0,049 +/-0.009mm), and Ti (0.074 +/-0.011mm). For marginal gaps, only abutment location's effect was significant (p = 0.003). Within PEKK, gaps at abutment 4 were significantly larger, compared with abutments 2 (p = 0.04) and 3 (p = 0.02).

CONCLUSIONS

The trueness of PEEK, PEKK, and Ti frameworks was different after milled. PEEK had the highest trueness. However, the marginal fit of the frameworks was similar and smaller than 90 µm in average.

CLINICAL RELEVANCE

PEEK, PEKK, and Ti complete-arch frameworks had clinically acceptable gaps and may therefore be recommended when their fit is considered. Higher trueness after milling did not result in better marginal fit.

Consecutive tooth agenesis patterns in non-syndromic oligodontia

Agenesis of two or more consecutive adjacent permanent teeth (consecutive tooth agenesis, CTA) is a serious manifestation of oligodontia requiring long-term, multi-disciplinary treatment. Therefore, the present study investigated the characteristics of the CTA pattern in orthodontic patients with non-syndromic oligodontia. Using panoramic radiographs, the number of agenetic permanent teeth excluding third molars in non-syndromic orthodontic patients was evaluated, and patients with six or more agenetic teeth (oligodontia group, n = 97) and with one to five agenetic teeth (hypodontia group, n = 107) were selected. The numbers of CTA including third molars in each quadrant and in each patient were compared between the groups. Each quadrant with CTA of patients was categorized into one of the following four types: (I) involves anterior teeth only; (II) involves posterior teeth only; (IIIA) includes anterior and posterior teeth; and (IIIB) separate in the anterior and posterior teeth. CTA in at least one quadrant was found in 91.8 and 4.7% of patients in the oligodontia and hypodontia groups, respectively. The highest frequency CTA patterns included agenesis of the first and second premolars and of the second and third molars in the oligodontia and hypodontia groups, respectively. In the oligodontia group, type IIIA was significantly more frequent in the maxillary than in the mandibular quadrant. Most oligodontia patients who visit orthodontic clinics have CTA. A rare but severe CTA pattern that continues from the anterior to posterior segments is more frequent in the maxillary than in the mandibular quadrant.

Dental implant displacement complicated by epulis fissuratum and extraoral fistula in a patient with senile dementia of Alzheimer's type

Dental treatment of patients suffering from mental illnesses should not be neglected as good condition of oral cavity is one of the factors that determine satisfactory quality of life, not only by aesthetic but also by functional considerations.

The Crucial Role of Plaque Control in Peri-Implant Mucositis Initiation as Opposed to the Role of Systemic Health Condition: A Cross-Sectional Study

Purpose

The aim of this study was to investigate the priority of periodontal plaque as a risk factor compared to other risk factors, namely hypertension and diabetes mellitus type II, regarding the initiation and severity of peri-implant mucositis, eventually reinforcing the importance of plaque control, periodic maintenance and supportive periodontic treatment after implant placement in order to prevent peri-implant diseases.

Patients and Methods

A total of 58 patients (84 implants) were enrolled; each individual implant was considered as a separate sample first, then sampling by patient was also applied, implants were divided into group A: systemically healthy patients and B: patients with hypertension and diabetes mellitus type II, the status of peri-implant tissue was followed after the healing abutment placement, with regard to implant mucosal index (IMI), probing pocket depth (PPD) and bleeding on probing (BOP); when sampling was done by patient, the mean of scores of all examined implants in each patient was taken to represent one sample.

Results

Group A implants showed higher mean scores of PPD (5.2 mm) than group B (4.2 mm) with significance (P = 0.014), and higher mean scores of BOP, group A = 0.71, group B = 0.45 with (P = 0.015); there was no statistical difference with regard to IMI, group A = 1.35, group B = 1.16 with (P = 0.172). Similar results were obtained when the sampling was calculated by patient; PPD: group A (5.31 mm), group B (4.75 mm) and P = 0.008, IMI: group A (1.34), group B (1.16) and P = 0.131, BOP: group A (0.75), group B (0.48) and P = 0.03.

Conclusion

In the absence of proper plaque control, systemic diseases showed no impact on the initiation and severity of peri-implant mucositis when compared to systemically healthy patients.

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Evaluation of the surgical and prosthetic success of All-on-4 restorations: a retrospective cohort study of provisional vs. definitive immediate restorations

Background

All-on-4 concept allows an immediate restoration, which is frequently a provisional restoration (PR), and will be replaced by a definitive restoration (DR) a few months later. However, this approach involves much higher treatment efforts and costs, compared to a DR immediately after implantation. PRs were mostly incorporated in the introductory phase of the All-on-4 concept in our respective clinics. Today, PRs are only used for referred patients and bimaxillary restorations. The aim of the study was to investigate whether PRs and DRs have comparable success rates.

Methods

A total of 126 patients with 136 All-on-4 restorations supported by 544 implants were included in this retrospective cohort study. The observation period was 1 year. In 42 cases, a PR was placed initially and replaced by a DR 3 months later. In 94 cases, a DR was placed immediately. Biological, technical, and severe (loss of an implant or PR/DR) complications associated with PRs and DRs were compared. The absence of a serious complication was considered a success.

Results

A total of 27 patients were affected by 33 complications, 19 biological (2 PR and 17 DR) and 14 technical (6 in PR and 8 in DR) in the first 3 months. Eight patients had ten severe complications (1 PR and 9 DR). Severe complications were all implant losses. Implant survival rate was 98.2% (99.4% PR and 97.6 DR), and restoration survival rate was 94.4% (97.6% PR and 92.6% DR). Six out of the ten implant losses occurred in the posterior maxillae of male patients. After 3 months, ten complications occurred in six patients within 1 year. One of these complications was an implant loss in the posterior maxillae of a male patient.

Conclusion

PRs and DRs showed comparable complication rates during the observation period. Only in male patients did implant losses occur more frequently in the posterior maxilla.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40729-021-00330-1.

Patient factors related to early implant failures in the edentulous jaw: A large retrospective case-control study

BACKGROUND

Dental implants provide anchorage for dental prostheses to restore functions for individuals with edentulous jaws. During the healing phase, proper osseointegration is required to prevent early implant failure. More knowledge is needed regarding factors related to early failure of dental implants.

PURPOSE

The aim of the present study was to identify possible risk factors for early implant failure, with respect to anamnestic and clinical parameters.

MATERIALS AND METHODS

All patients with edentulous jaws with early implant failure (n = 408) from one referral clinic were compared with a matched control group (n = 408) with no implant failure. Early implant failure was identified during the first year of prosthetic function. Matching was performed on age, gender, year of surgery, type of jaw, and type of implant surface. In addition, data on anamnestic and clinical parameters were collected. The data were analyzed with a multivariable logistic regression model using early implant failure as the binary outcome.

RESULTS

Five anamnestic factors were statistically significant with respect to higher probability for early implant failure: systemic disease, allergies in general, food allergies, smoking, and intake of analgesic medication. Four clinical conditions (i.e., implants in the opposing jaw, low primary stability, reduced bone volume, and healing complications) were also related to higher probability for early implant failure.

CONCLUSIONS

This study identified nine factors associated with early implant failure, several related to patient's general health. Further investigations are needed to fully understand the causality between the obtained variables and early implant failure.