Evaluation of masticatory performance and patient satisfaction for conventional and 3D-printed implant overdentures: a randomized crossover study.

BACKGROUND: This crossover clinical study aimed to evaluate and compare masticatory performance and patient satisfaction for patients rehabilitated with conventional heat-cured acrylic resin and 3D-printed mandibular implant overdentures retained with bar attachment. MATERIALS AND METHODS: Sixteen completely edentulous healthy participants received new conventional dentures. In the mandible, four interforaminal implants were inserted. Following the stage of osseointegration, the bar was constructed in a trapezoidal configuration. Each patient randomly received the following overdentures using a crossover design: (1) conventional heat-cured acrylic resin overdenture and (2) 3D-printed overdenture (developed by scanning of mandibular conventional overdenture). The masticatory performance was assessed by conducting a two-colour mixing ability test at 5, 10, 20, 30, and 50 masticatory cycles. Moreover, the McGill Denture Satisfaction Questionnaire (MDSQ) was employed to assess patient satisfaction. Evaluation was performed after 3 months of using each overdenture. Paired sample t tests were used to compare the masticatory performance and MDSQ scores of patients for both prostheses. RESULTS: No significant difference in masticatory performance was reported between the two types of overdentures. Regarding patient satisfaction, only the esthetic aspect was significantly better for conventionally processed overdentures than for printed overdentures. Insignificant differences were observed regarding other MDSQ items between the two overdentures. CONCLUSION: Within this clinical study, 3D-printed implant overdentures showed promising results in terms of chewing efficiency and patient satisfaction compared to conventionally fabricated implant overdentures. TRIAL REGISTRATION: Retrospectively registered at www. CLINICALTRIALS: gov : NCT06148727.(28/11/2023).

Mandibular overdenture with a single implant in the canine region (c-SIMO): a feasibility study.

OBJECTIVES: The aim of this multi-center pilot study was to assess the viability and feasibility of a novel treatment concept - the canine-positioned single implant mandibular overdenture (c-SIMO), with the single implant placed on the patient's preferred chewing side instead of the midline. MATERIALS AND METHODS: Participants received a single implant in the canine region of their preferred chewing side, based on an Asymmetry Index observed during mastication. The pre-existing mandibular denture was transformed into a c-SIMO on a spherical attachment. The primary outcome was oral health-related quality of life (OHRQoL), measured with GOHAI and OHIP-EDENT. Secondary outcomes included denture satisfaction index (DSI), chewing efficiency (CE), maximum bite force (MBF), implant survival and success, and prosthetic maintenance. Data analysis included descriptive statistics and bivariate comparison tests. RESULTS: Fifteen participants received the c-SIMO treatment (mean age: 69.9 ± 7.0). Implant success and survival rates were 100% at 1 year. Patient-reported outcome measures improved significantly compared to pre-treatment values (OHIP-EDENT: p = 0.001; DSI: p = 0.001; GOHAI: p = 0.002). Masticatory outcomes also improved significantly (CE: p = 0.001; overall MBF: p = 0.005). Post-implant, MBF was significantly higher in the ipsilateral side compared to the contralateral side at 2 weeks (p = 0.019) and 3 months (p = 0.015), but no longer at T3 (p = 0.730). Common prosthodontic events included denture base adjustments (n = 17) and matrix activation (n = 9). CONCLUSIONS: This pilot study concludes that c-SIMO is a promising treatment option, and a potential alternative to the single midline implant overdenture. CLINICAL RELEVANCE: The novel treatment concept of a canine-positioned single implant mandibular overdenture could be a viable treatment alternative to the midline positioning.

Influence of implant distribution on the biomechanical behaviors of mandibular implant-retained overdentures: a three-dimensional finite element analysis.

OBJECTIVE: To assess stress distribution in peri-implant bone and attachments of mandibular overdentures retained by small diameter implants, and to explore the impact of implant distribution on denture stability. METHODS: Through three-dimensional Finite Element Analysis (3D FEA), four models were established: three models of a two mandibular implants retained overdenture (IOD) and one model of a conventional complete denture (CD). The three IOD models consisted of one with two implants in the bilateral canine area, another with implants in the bilateral lateral incisor area, and the third with one implant in the canine area, and another in the lateral incisor area. Three types of loads were applied on the overdenture for each model: a 100 N vertical load and a inclined load on the left first molar, and a100N vertical load on the lower incisors. The stress distribution in the peri-implant bone, attachments, and the biomechanical behaviors of the overdentures were analyzed. RESULTS: Despite different distribution of implants, the maximum stress values in peri-implant bone remained within the physiological threshold for all models across three loading conditions. The dispersed implant distribution design (implant in the canine area) exhibited the highest maximum stress in peri-implant bone (822.8 µe) and the attachments (275 MPa) among the three IOD models. The CD model demonstrated highest peak pressure on mucosa under three loading conditions (0.8188 Mpa). The contact area between the denture and mucosa of the CD model was smaller than that in the IOD models under molar loading, yet it was larger in the CD model compared to the IOD model under anterior loading. However, the contact area between the denture and mucosa under anterior loading in all models was significantly smaller than those under molar loading. The IOD in all three models exhibited significantly less rotational movement than the complete denture. Different implant positions had minimal impact on the rotational movement of the IOD. CONCLUSION: IOD with implants in canine area exhibited the highest maximum stress in the peri-implant bone and attachments, and demonstrated increased rotational movement. The maximum principal stress was concentrated around the neck of the small diameter one-piece implant, rather than in the abutment. An overdenture retained by two implants showed better stability than a complete denture.

Single lateral implant for mandibular overdentures as a fallback solution or a viable treatment alternative: Four case reports.

This report of four clinical cases aims to illustrate the use of a lateral implant as a solution for implant overdentures in the mandible in different clinical situations. The first two cases describe the clinical situations of patients wearing two-implant mandibular overdentures until the failure of one of the implants, one due to implant loss and the other due to a fracture of an abutment screw, and how the conditions were managed. The third case illustrates the placement of a single implant to retain an overdenture, where a midline implant, as originally planned, was not feasible due to anatomic reasons. The final case describes the use of a lateral implant to support and retain a single-implant mandibular overdenture. The four cases demonstrate that a single lateral implant can be utilized as sole retention in cases of a failing contra-lateral implant and as an alternative to a single implant in the midline.

Surface Wear and Retention Force of Zirconia and PEKK Implant-retained Crowns.

PURPOSE: The aim of this study was to evaluate the surface wear and retention force of telescopic attachments made of zirconia primary crowns and poly-ether- ketone -ketone (PEKK) secondary crowns for 2-implant retained mandibular complete overdentures. MATERIALS AND METHODS: Ten healthy completely edentulous patients aged 55-60 years were selected for this study. Each patient received two implants in the mandibular canine regions. Maxillary conventional complete dentures were constructed against implant-retained mandibular overdentures for all patients. Zirconia- PEKK telescopic attachments were fabricated to retain the overdentures where primary copings were constructed of zirconia and secondary ones were constructed of PEKK. Retention force and surface wear were evaluated at the time of overdenture insertion (T0), and after 6 months of overdenture use (T6). RESULTS: The results revealed less wear of zirconia copings compared to PEKK ones at T0 and T6. However, both materials showed insignificant wear after 6 months of overdenture use. A significant increase in retention force was observed after 6 months of overdenture use. CONCLUSION: Within limitations of this study, PEKK may be considered a promising alternative material for telescopic secondary crowns construction combined to zirconia primary ones, regarding the wear resistance and the satisfactory retention forces.

Use of mini implants for the two-implant retained mandibular overdenture: A prospective study.

Background: The two-implant retained mandibular overdenture utilizing nonsplinted implants is a proven treatment modality for completely edentulous patients. However, a lacuna still exists regarding the suitability of mini dental implants for this purpose. The purpose of the study was to evaluate implant stability and crestal bone loss in single-piece mini dental implants loaded with immediate or conventional loading protocols to retain a mandibular overdenture. Method: Twenty-four completely edentulous patients were rehabilitated using conventional maxillary complete denture and a mandibular two-implant retained overdenture utilizing nonsplinted single piece mini implants. The implants were loaded with immediate or conventional loading protocols. Implant stability (with Periotest TM) and crestal bone loss (with radiovisiograph and radiographic grid) were evaluated at the time of loading and at one, two, and six months after loading. Statistical analysis was done with the Independent Samples "t" test and One-Way ANOVA. Results: Mean Periotest Values observed were significantly more negative in implants loaded with the conventional loading protocol. Crestal bone loss was significantly lesser in the immediate loading protocol but was still higher than the requisite 1.5 mm postulated by established criteria. Conclusion: Two single-piece nonsplinted mini implants may be sufficient to retain a mandibular overdenture utilizing the immediate loading protocol. Further studies with a longer duration of observation and larger sample size are required.

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.

Evaluation of bite force, quality of life, and patients' satisfaction in elderly edentulous patients using implant overdentures.

Purpose: This study aimed to compare the bite force (BF) between complete dentures and implant overdentures (IODs) retained by two mandibular implants. Additionally, we evaluated the quality of life (QoL) and patient satisfaction among individuals using IODs. In addition, the effects of demographic parameters such as age and sex, and clinical parameters such as implant length, implant diameter, attachment height, attachment color, and interimplant distance on BF, QoL, and patient satisfaction were evaluated. Materials and methods: A total of 51 edentulous patients rehabilitated with the maxillary complete dentures and mandibular IODs retained by two implants were included in this study. BF was measured using a force meter pre- and post-implant in the same patients. Oral health-related quality of life (OHRQoL) was assessed with the Oral Health Impact Profile (OHIP-14) and patient satisfaction was assessed with the Visual Analog Scale (VAS) questionnaires. Results: It was found that BF values were statistically higher for IODs than complete dentures (P < .001). In terms of attachment height of the OHIP scores, there was a significant difference in the psychological disability and social disability domains (P < .05). When examining the change in patient satisfaction as a function of sex, it was found that mandibular retention satisfaction differed significantly by sex (P < .05), but there was no significant difference in the other domains. Conclusion: Within the limitations of this study, it was observed that the BF increased after the use of IODs. Several factors, including age, interimplant distance, attachment height, and attachment color, were found to impact OHRQoL. Sex and implant diameter were identified as factors affecting patient satisfaction.

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.

The effect of different denture cleansing solutions on the retention of polyetheretherketone locator attachments.

PURPOSE: Prosthetic cleansing solutions have been reported to cause retention loss in implant locator attachments due to the chemical alterations of these attachments. This study aimed to investigate the effects of different denture cleansing solutions on attachments with different retention values. MATERIALS AND METHODS: In this study, 160 polyetheretherketone locator attachments were divided into 4 groups according to their attachment retention values (yellow, pink, clear, and violet). Forty attachments from each group were soaked in four different cleansing solutions (n = 10). The attachments from the four groups were immersed in water, sodium hypochlorite, Corega, and Protefix solutions for a period equivalent to 6 months, according to the manufacturer's recommendations. The locator attachments were then subjected to testing using a universal testing machine. Maximum load to dislodgement according to different solutions was evaluated by one-way ANOVA test. Statistical significance was set at p < 0.05. RESULTS: The effect of denture cleansing solutions on the retentive values of attachments was statistically significant (p < 0.001). Among all cleansing solutions, the highest retention value was found in the violet attachments, and the lowest retention value was found in the yellow attachments. The lowest retention value (0.72 ± 0.05 MPa) was observed when the yellow attachments were immersed in Protefix solution, and the highest retention value (1.96 ± 0.15 MPa) was observed when the violet attachments were immersed in the Corega solution. CONCLUSION: For different colored attachments, different cleansing solutions can be suggested to patients.

Maxillary implant overdenture retained by four unsplinted attachments and opposed by a natural or fixed dentition: Five-year clinical outcomes. A prospective case series.

OBJECTIVES: The objective of this study was to assess, over a period of 5 years, implant prosthesis and patient-reported outcomes of complete dentures retained by four implant-supported attachments in the edentulous maxilla facing either natural teeth or fixed rehabilitation in the lower jaw. MATERIALS AND METHODS: Implant, prosthodontic and patient-related outcomes were assessed in 30 patients at 1, 3 and 5 years. Prosthodontic survival, complications or maintenance events as well as implant survival were recorded. Patient-reported outcome measures (PROMs) were evaluated with the Oral Health Impact Profile (OHIP-20) questionnaire and a visual analogue scale (VAS) before implant placement (baseline) and during the follow-up period. RESULTS: After 5 years, three patients dropped out, 21 implants failed, and four overdentures were replaced leading to a prosthesis survival rate of 85.2% (95% CI: 71.8%-98.6%) and an implant survival rate of 80.6% (95% CI: 73.1%-88.0%). Prosthodontic success rate decreased from 86.2% to 74% between the 1st and the 3rd year and reached 63% after 5 years. OHIP results improved significantly from baseline to 1 year (p < .0001) and to 3 years (p = .036), but, at 5 years, the improvement was no longer significant when compared to baseline (p = .12). The overall VAS score remained significantly higher up to 5 years (p < .001). CONCLUSION: A substantial number of prosthetic complications and replacements occurred over the 5-year follow-up. After 5 years, the OHIP-20 deteriorated and reached again the baseline level. Nonetheless, the VAS results suggest significantly increased patient satisfaction after implant-supported retention was provided for the removable prostheses.

Retentive force of a conical crown with CAD/CAM-fabricated PEEK and zirconia secondary crowns on titanium implant abutments.

This study aimed to evaluate the retentive force of polyetheretherketone (PEEK) and zirconia secondary crowns on ready-made titanium implant abutments (with height, diameter, and taper as 5.5 mm, 4.5 mm, and 6°, respectively) as the primary crown. PEEK, zirconia, and titanium secondary crowns were fabricated using a CAD/CAM system. Insertion and removal tests of secondary crowns on the primary crown were conducted for 2,000 cycles. The initial retentive forces recorded at the 100th cycle for PEEK, zirconia, and titanium were 13.0±7.9, 2.9±2.6, and 27.6±1.7 N, respectively. The retentive forces of PEEK and zirconia showed no significant difference among all cycles. However, the retentive force of the titanium used as a control decreased (20.3±2.8 N) significantly at the 2,000th cycle. Although the retentive force of PEEK was lower than that of titanium, it was within the range that can provide a suitable retentive force of 5 N for removable dental prostheses.

Stress distribution of one-piece and two-piece mini-Implant overdentures with various attachment systems and diameters: A finite element analysis.

PURPOSE: We investigated and compared the stress distribution within one- and two-piece mini-implants for overdentures with three different attachments (ball, Locator, and magnet) and two different diameters using three-dimensional finite element (3D FE) analysis and a monotonic bending test. The goal was to identify the most beneficial implant attachment system design for mini-implant overdentures with a lower risk of implant fracture. METHODS: Twelve 3D FE models simulating a mandible segment with one- and two-piece mini-implants with different attachment systems, diameters, and overdentures were created using three-dimensional computer-aided design (CAD) software. Vertical and oblique forces (45° to the longitudinal axis of the implant) of 100 N were applied to the dentures. The stress distribution was analyzed. A bending test was performed on a mini-implant (Locator, 2.4 mm) using a testing machine to quantify the load at yield stress. RESULTS: One-piece mini-implants showed lower maximum stress compared to two-piece mini-implants. Among the three designs, the magnet attachment systems showed the maximum stress. The maximum von Mises stress occurred at the neck of the implants, which was surrounded by cortical bone in all models, and under both loading conditions. CONCLUSIONS: Focusing on the attachments and one- and two-piece designs of mini-implant overdentures using CAD models to reduce confounding factors affecting the stress distribution, we concluded that one-piece mini-implants tended to show lower stress compared to two-piece mini-implants. Mini-implant overdentures with Locator and ball attachments demonstrated lower stress within the implants compared to those with magnet attachments under vertical and oblique loading conditions.

Accuracy of Selective Laser Melted Bar Retaining Mandibular Implant-Assisted Overdenture: An In Vitro Comparison of Different Impression Materials and Techniques.

This study aimed to assess the accuracy of the marginal fit of 2 implant-supported overdenture bars fabricated with selective laser melting technology, using polyvinyl siloxane and vinyl siloxane ether impression materials and different impression techniques. Two implants with multi-unit abutments were inserted in a 3D-printed mandibular model and used as a reference model, then duplicated into a stone cast to fabricate custom trays for obtaining impressions with polyvinyl siloxane and vinyl siloxane ether impression materials, using both open and closed-tray techniques. This resulted in a total of 4 groups, each with 8 specimens. The impressions were poured and scanned, and 32 cobalt-chromium bars were fabricated using selective laser melting technology. Each bar was screwed onto one abutment of the reference model, and a standardized digital periapical radiograph of the opposite unscrewed side was taken; this process was repeated to the other abutment. The vertical misfit was measured at 3 predetermined positions on the unscrewed side, and 6 values per bar were recorded. The mean gap distance was measured, and the data were subjected to statistical analysis; the present study found that the open-tray technique with vinyl polyether siloxane impression material may offer improved accuracy for obtaining impressions for 2 implant-supported bars. The open-tray technique groups also showed better marginal fit than the closed-tray groups. However, further clinical research is required to confirm these findings.

Sobredentadura parcial como alternativa de tratamiento en paciente con secuela periodontal. Reporte de caso

La rehabilitación de pacientes desdentados parciales periodontalmente comprometidos es un desafío a nivel protésico. Esto se debe a que la condición de los dientes pilares no siempre es la adecuada, viéndose afectada la proporción corono-radicular por las secuelas de una enfermedad periodontal. Es en estas situaciones límite donde el uso de implantes óseo-integrados acompañado de ataches resilientes mejora la retención de una prótesis parcial removible convencional, disminuyendo el riesgo de sobrecarga en los dientes remanentes. En este reporte de caso se presenta una rehabilitación integral, resuelto con una sobredentadura parcial maxilar sin cobertura palatina sobre pilares Locator®, minimizando la carga en los dientes remanentes del grupo II con secuelas periodontales; y una rehabilitación del arco mandibular con operatoria directa, indirecta y prótesis fija, recuperando funcionalidad, soporte oclusal y manteniendo los dientes remanentes en el sector anterior.

Rehabilitation of periodontally compromised partially edentulous patients has always been a challenge at the prosthetic level, because the condition of the remaining teeth is not always adequate and the crown-root ratio is often affected by the sequelae of periodontal disease. In these borderline situations, the use of osseointegrated implants accompanied by resilient attachments improves the retention of a conventional removable partial denture, reducing the risk of overloading the remaining teeth. This case report presents a comprehensive rehabilitation, resolved with a maxillary partial overdenture without palatal coverage on Locator® abutments, minimizing the load on the remaining pieces of group II with periodontal sequelae; and a rehabilitation of the mandibular arch with direct, indirect and fixed prosthesis. In this way, it was possible to recover functionality, occlusal support and keep the remaining teeth in the front part of the maxilla.

Mandibular 3-implant overdenture: A clinical report of a novel design.

OBJECTIVE: To report on the use of a mandibular 3-implant overdenture with a novel implant distribution opposing a maxillary complete denture for the rehabilitation of an older edentulous patient. BACKGROUND: The use of oral implants with attachment systems of various numbers and designs to support removable partial and complete dentures is well documented with success and predictability. MATERIALS AND METHODS: An older edentulous patient with a mandibular implant-assisted removable partial denture was presented with failing remaining dentition. Teeth were extracted and a single midsymphyseal implant was placed. A mandibular overdenture on three implants with ball attachments in a tripod distribution was constructed to oppose a new maxillary complete denture made using a modified impression technique. RESULTS: Over 2 years of follow-up, no significant biological or mechanical complications were reported, and denture retention and stability remained optimum. CONCLUSION: Mandibular overdentures on three implants with ball attachments in a tripod distribution, opposing a maxillary complete denture, could be an alternative treatment option for the older edentulous patients.

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.

Current complications and issues of implant superstructure.

The purpose of this review is to search for complications of dental implant superstructures and consider the issues involved. This narrative review was performed by searching through PubMed databases and review articles that were published after 1990. Misfitting of the superstructure can result in loosening of screws, reduced preload, and in some cases, significant stress around the implant. External connection modalities and single implant prostheses have been reported to have more loose or broken abutment screws. In addition, when zirconia abutment was used for platform shifting, the rate of fracture of the abutment was considered to be high. Additionally, it was reported that men were significantly at an increased risk of abutment fracture. As for the retention mechanism of implant overdenture, stud attachment (Locator type) should receive more attention to wear and damage of retention parts than other attachments. The causes of the complications of implant superstructures have not been clarified in some cases, and further verification is required. Verification of complications is considered important to obtain a long-term prognosis for superstructures of implants. It will be necessary to further verify complications of implants in the future.

Effect of Sinus Perforation with Flaplessly Placed Mini Dental Implants for Oral Rehabilitation: A 5-Year Clinical and Radiological Follow-Up.

BACKGROUND: Flaplessly placed one-piece mini dental implants (MDI) are an option to support maxillary overdentures. Evenly distribution of the implants over the atrophic alveolar process implies a risk of accidental sinus perforation in the posterior area which could induce sinus-related pathology. METHODS: Thirty-one patients received 5-6 maxillary MDIs. Schneiderian membrane swelling was assessed with CBCT at the deepest point of the sinus in the mid-sagittal plane prior to surgery (baseline), after 2 and 5 years. Additionally, subjective patient-reported rhinosinusitis complaints, the effect of smoking, and gender differences were investigated. RESULTS: Mean thickness of the Schneiderian membrane was 2.87 mm at baseline, 3.15 mm at 2 years, and 4.30 mm at 5 years in 27 of 31 initially treated patients. MDI perforation was detected in 21/54 sinuses. At 2 years, perforation length does not affect membrane thickness whereas baseline swelling does. In smokers, each perforated mm induced 0.87 mm additional swelling. After 5 years, the effect of baseline swelling becomes smaller whereas perforation length became statistically significant, with 0.53 mm increase for every perforated mm. The effect of smoking lost its significance. No relations between gender, membrane thickness changes, or subjective clinical sinus complaints and MDI perforation were found. CONCLUSION: Accidental MDI sinus perforation induces Schneiderian membrane swelling but does not interfere with clinical sinusal outcome after 5 years.

Immediate versus Delayed Attachment Incorporation Impact on Prosthetic Aftercare among Mandibular Implant-Supported Overdenture Wearers.

BACKGROUND: Substantial effort is dedicated to finding the most favorable parameters that will ensure low aftercare demands among edentulous patients wearing mandibular implant supported overdentures (MISODs). The purpose of this retrospective cohort study was to compare prosthetic aftercare between MISOD patients with a simultaneous (group A) vs. a three-week settling in period (group B) prior to attachment incorporation. METHODS: Forty-five patients enrolled in this study. Two implants per patient were placed using a two-stage implant insertion protocol. Second-stage surgery was performed after three months. All patients received ball attachments using the direct (chairside) incorporation method. Twenty-two patients received their dentures with simultaneous attachment activation and the rest-twenty-three patients-after a three-week settling in period. Patients' files were scanned for aftercare visits. Outcome parameters included sore spot relief, attachment incorporation, and denture repair. Additionally, gingival index measurements were compared. Confounding factors included age, gender, and implant dimensions. RESULTS: The mean follow-up for the entire cohort was 84 ± 21 months, and the range 39-120 months. The mean number of visits for group A vs. B respectively: pressure sores relieve (3.63 ± 0.84 vs. 3.71 ± 0.61, p = 0.581), liner exchange due to loss of retention (2.09 ± 1.03 vs. 2.31 ± 1.04 p = 0.487), and gingival index (1.3 ± 0.3 vs. 1.03 ± 0.2, p = 0.653) exhibited no statistically significant differences between the tested groups. No statistically significant differences between the groups were also noted for the denture repair aftercare treatments (p = 0.318) and the independent variables including age, gender, and implant length. CONCLUSIONS: Prosthetic aftercare in MISOD wearers is similar whether a simultaneous or a three-week settling in period for attachment incorporation is applied.