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.

In vitro shear bond strength between fluorinated zirconia ceramic and resin cements

PURPOSE: The purpose of this study was to evaluate the efficiency of a gas-phase fluorination method under different fluorination periods through using two resin cements. MATERIALS AND METHODS: 84 zirconia specimens in dimensions of 5 mm × 5 mm × 2 mm were prepared and surface treated with 50 µm aluminum oxide particles or gas phase fluorination for 2 min, 5 min, or 10 min. One specimen in each group was surface analyzed under scanning electron microscope. The remaining specimens were bonded to composite cylinders in dimensions of 2 mm diameter and 3 mm high with Panavia SA Plus or Variolink N. Then, the specimens were stored in 37℃ distilled water for 24 hours and shear bond strength test was applied at a speed of 1 mm/min. RESULTS: The highest shear bond strength values were observed in the samples fluorinated for 5 minutes and cemented with Panavia SA Plus. Variolink N did not elicit any statistical differences between surface treatments. Panavia SA Plus resin cement and Variolink N resin cements featured statistically significant difference in shear bond strength values only in the case of 5 minutes of fluorination treatment. CONCLUSION: According to the results of this study, application of 5 minutes of fluorination with 10-methacryloyloxydecyl dihydrogen phosphate monomer (MDP) containing Panavia SA Plus resin cement increased the resin bond strength of zirconia. Fluorination of the zirconia surface using conventional resin cement, Variolink N, did not lead to an increase in bond strength.

Influence of nano alumina coating on the flexural bond strength between zirconia and resin cement

PURPOSE: The purpose of this in vitro study is to examine the effects of a nano-structured alumina coating on the adhesion between resin cements and zirconia ceramics using a four-point bending test. MATERIALS AND METHODS: 100 pairs of zirconium bar specimens were prepared with dimensions of 25 mm × 2 mm × 5 mm and cementation surfaces of 5 mm × 2 mm. The samples were divided into 5 groups of 20 pairs each. The groups are as follows: Group I (C) – Control with no surface modification, Group II (APA) – airborne-particle-abrasion with 110 µm high-purity aluminum oxide (Al2O3) particles, Group III (ROC) – airborne-particle-abrasion with 110 µm silica modified aluminum oxide (Al₂O₃ + SiO2) particles, Group IV (TCS) – tribochemical silica coated with Al2O3 particles, and Group V (AlC) – nano alumina coating. The surface modifications were assessed on two samples selected from each group by atomic force microscopy and scanning electron microscopy. The samples were cemented with two different self-adhesive resin cements. The bending bond strength was evaluated by mechanical testing. RESULTS: According to the ANOVA results, surface treatments, different cement types, and their interactions were statistically significant (P < .05). The highest flexural bond strengths were obtained in nanostructured alumina coated zirconia surfaces (50.4 MPa) and the lowest values were obtained in the control group (12.00 MPa), both of which were cemented using a self-adhesive resin cement. CONCLUSION: The surface modifications tested in the current study affected the surface roughness and flexural bond strength of zirconia. The nano alumina coating method significantly increased the flexural bond strength of zirconia ceramics.