The effect of different attachment systems with implant-retained overdentures on maximum bite force and EMG.

OBJECTIVE: To compare the effect of different attachment systems with implant-retained overdentures on maximum bite force and muscle activity using electromyography (EMG). BACKGROUND: Denture retention and stability is of considerable interest in prosthetic dentistry. MATERIALS AND METHODS: Thirty-five patients were examined: 15 edentulous patients treated with mandibular implant-retained overdentures (MIRO) and maxillary dentures (MCD) (two implant-ball attachment) (BC); 10 edentulous patients treated with MIRO and MCD (four implants-bar attachments) (BRC); 10 patients with edentulous mandibular treated with MIRO and maxillary fixed partial dentures (MFPD) (two implant-ball attachments) (BF). Before implant placement all patients received new dentures. After using these dentures for 3 months the maximum bite force and electrical activity of masseter muscle were measured. Two or four implants were then inserted into the intraforaminal region. After osseointegration periods, patients were treated with MIRO which duplicated their dentures and after three months the measurements were repeated. The data were collected and statistically analysed. RESULTS: Muscle activity and chewing ability increased in the second period of measurements. Also chewing time was significantly decreased at the first measurements. The highest muscle activity was observed in the group of patients treated with group BF. CONCLUSION: The EMG values of the masseter muscle significantly increased when an implant attachments was used in the overdenture.

Effect of denture adhesive on the micro-organisms in vivo.

BACKGROUND: Denture adhesives increase the retention and stability of dentures in edentulous patients, especially in cases where salivary flow is impaired or in the management of traumatised oral mucosa. OBJECTIVES: The effect of a denture adhesive on the oral flora at different time intervals. METHOD: Thirty denture-wearing patients were involved in this study. While half of the group received a denture adhesive, the other half did not. At baseline, 1 and 2 months after delivering the dentures, smear samples were obtained from the saliva, palate and the dentures. Candida albicans, Candida krusei, Candida glabrata, Candida spp., Staphylococcus aureus, Moraxella catarrhalis, α-haemolytic streptococci, ß-haemolytic streptococci, Pneumococcus aureus, S. anginosus, S. intermedius, S. constellatus, S. sanguis, S. gordonii, S. mitis, S. mutans, S. salivarius, and yeasts were investigated. The data were statistically analysed using anova and repeated measures. RESULTS: Most types of the micro-organisms were not seen and could not be analysed statistically except α-haemolytic streptococci and C. albicans. No statistically significant difference was found for α-haemolytic streptococci and C. albicans in saliva, palate and the denture at all time intervals. CONCLUSIONS: Prolonged use of the denture adhesive tested up to 2 months did not yield to increase in micro-organisms of the oral flora.

Five-year treatment outcomes with three brands of implants supporting mandibular overdentures.

PURPOSE: The purpose of this study was to evaluate clinical outcomes, posttreatment care, and patient satisfaction with overdenture treatment in the severely resorbed mandible. MATERIALS AND METHODS: Two implants were inserted in the intraforaminal region of 36 edentulous patients. Seventy-two implants were placed: 24 ITI (Institut Straumann), 24 SwissPlus (Zimmer Dental), and 24 Astra (Astra Tech). Implants were not loaded until osseointegration was complete. Following osseointegration and insertion of the prosthesis, the implants were evaluated by clinical and radiographic parameters. Clinical parameters, including Plaque Index, Sulcus Bleeding Index, peri-implant probing depth (PD), and marginal bone loss (MBL), were recorded, and any biologic and mechanical complications at baseline and recall evaluations were noted. Patient satisfaction with mastication, phonetics, retention, oral hygiene, and esthetics was also evaluated by means of a questionnaire. The results were analyzed statistically. RESULTS: The cumulative implant survival rate after 5 years of loading was 100%. There were significant differences in mean PD values between the three implant groups at baseline and recall evaluations. Mean PD values for the Astra group were significantly higher than those for the ITI and SwissPlus groups. Although the mean MBL was within clinically acceptable levels for all groups, there were significant differences among the three groups for MBL scores between baseline and 5 years. The mean MBL for the ITI group was significantly lower than the MBL values seen for the Astra and SwissPlus groups. Over the 60-month evaluation period, the most common prosthetic complications were mandibular denture fracture and dislodgement of the female attachment. CONCLUSIONS: Mandibular implant overdenture treatment is a successful treatment modality for the severely resorbed mandible.

Surgical and prosthodontic treatment using alveolar distraction osteogenesis and implant placement for a patient with mandibular prognathism: a clinical report.

A 49-year-old patient presented with an Angle Class III malocclusion with a partially edentulous mandible, as diagnosed by orofacial examination and radiographic and cephalometric analyses. The patient refused orthognathic surgery; therefore, the treatment plan included the preparation of all teeth and fabrication of provisional restorations to reestablish optimal occlusion. To allow for the placement of 3 implants, the edentulous posterior mandibular ridge was improved via alveolar distraction. The patient was recalled 3, 6, 12, and 24 months after prosthodontic treatment. The oral situation was stable and patient satisfaction was reported as high.

Resonance frequency analysis assessment of implant stability in labial onlay grafted posterior mandibles: a pilot clinical study.

PURPOSE: The objectives of this study were (1) to compare the stability, evaluated by means of resonance frequency analysis (RFA), of implants placed posterior mandibles augmented with autogenous bone harvested from the mandibular symphysis with that of implants placed in nongrafted edentulous posterior mandibles and (2) to compare peri-implant marginal bone height changes and implant failure for the 2 groups. MATERIALS AND METHODS: Eight patients with thin posterior mandibular ridges (buccolingual crestal width less than 4 mm) underwent labial onlay alveolar grafting with symphyseal bone blocks 4 months prior to placement of 17 implants. Seven nongrafted patients received 18 implants in the edentulous posterior mandible; these patients served as a control group. RFA was performed the day of implant placement (baseline), 1 month postplacement, 4 months postplacement (after prosthesis delivery), and 12 months postloading. Peri-implant bone height changes at a level of 0.01 mm were assessed using periapical radiographs at baseline, the 1-month follow-up, and the 4-month follow-up. Analysis of variance was used to evaluate statistical differences within the groups, and t test was used to make comparisons between groups. RESULTS: None of the patients presented postoperative complications or implant failure. Mean implant stability quotient (ISQ) was 63.0+/-6.0 to 70.2 +/-3.5 for the grafted group and 64.1+/-4.1 ISQ to 70.1+/-3.9 for the nongrafted group. No significant difference was found in mean ISQ between the grafted and nongrafted groups at baseline, the 1-month follow-up, 4 months postplacement, or 12 months postloading (P = .211, P = .873, P = .925, P = .735, respectively). Mean peri-implant bone loss was 0.16 +/- 0.04 mm mesially and 0.16 +/- 0.05 mm distally. CONCLUSION: RFA revealed no difference in implant stability between mandibular ridges augmented with autologous bone grafts at baseline or after loading.

Three-year treatment outcomes with three brands of implants placed in the posterior maxilla and mandible of partially edentulous patients.

STATEMENT OF PROBLEM: Survival rates of implants in posterior regions vary among clinical studies. Problems occur more often in the posterior segment of the maxilla due to proximity of the maxillary sinus and reduced quality or quantity of alveolar bone. PURPOSE: This clinical study evaluated the treatment outcomes of 3 brands of implants in the posterior maxillae and mandibles of 63 patients. Treatment outcomes of all implants were assessed according to implant type, location, patient gender, periodontal status, and prosthesis type. MATERIAL AND METHODS: A total of 203 implants-105 ITI (ITI), 53 Camlog (CAM), and 45 Frialit (FRI)-were placed in 63 patients (38 women, 25 men). One hundred twelve implants were located in the posterior mandible and 91 in the posterior maxilla. All implants were longer than 10 mm and had a diameter larger than 3.5 mm. Implants in the ITI group were placed in a 1-stage surgery. The CAM and FRI groups were treated with a 2-stage surgical protocol. Implants were not loaded until osseointegration was complete, which was determined clinically and radiographically. At that point, implants were restored with 50 single crowns and 81 fixed partial dentures (FPDs). While 11 FPDs connected implants to natural teeth, 70 FPDs were supported by implants only. Standardized radiographs were made, and clinical parameters were recorded at prosthesis insertion (baseline) and at each recall evaluation (6, 12, 24, and 36 months). Plaque index (PI), sulcus bleeding index (SBI), peri-implant probing depth (PD), and radiographic marginal bone loss (MBL) levels were recorded at baseline, along with any biological and mechanical complications. Repeated-measures ANOVA, Kruskal-Wallis test, Wilcoxon signed rank test, and paired samples tests were used for statistical analysis (alpha=.05). RESULTS: One implant was lost during the osseointegration period in 1 woman due to infection. The cumulative implant treatment outcome was 99.3%. At the 3-year recall, plaque accumulation was significantly higher than baseline scores (P=.01, Wilcoxon signed rank test). Eight percent of the patients presented>2 mm PD at 2-year recall. The influence of observation time was found to be significant for the mean MBL values between groups (P=.001). When MBL values were compared between groups, no significant differences were found. For 1 patient in the FRI group, abutment loosening was observed and both the crown and the abutment were replaced. Patient satisfaction in all groups was high. CONCLUSION: The 3 brands of implants evaluated in this study exhibited similar positive treatment outcomes after 3 years.

The effect of a new denture adhesive on bite force until denture dislodgement.

PURPOSE: Denture adhesives are used to improve the denture retention and comfort of complete denture wearers. The purpose of this investigation was to establish the effect of a new denture adhesive on maximum bite force until denture dislodgement (BFDD) after adhesive application. MATERIALS AND METHODS: Fifteen denture-wearing patients (7 female, 8 male, mean age: 64 years) were involved in the study. The BFDD measurements were performed using a disposable gnathometer with a 1 to 10 scale. During one of the treatment sessions, the maximum BFDD with the pre-existing maxillary dentures using denture adhesive were measured. The measurements were also made at the baseline without adhesive and after the 1st, 2nd, 4th, and 6th hours following the application of the denture adhesive. The same procedure was applied to the new dentures about 2 weeks after the delivery of the dentures. The data were collected and statistically analyzed using ANOVA and Student's t-test. RESULTS: Consistent improvement was observed in BFDD when adhesive was used for all time intervals from the baseline (mean: 1.54 units, 3.20 units) to 6 hours (mean: 3.99 units, 4.60 units) for both pre-existing dentures (p= 0.003) and new dentures (p= 0.05), respectively. CONCLUSIONS: The results of this in vivo study suggest that the denture adhesive tested could effectively increase BFDD for up to 6 hours after application.