Effect of Different Primers on Shear Bond Strength of Base Metal Alloys and Zirconia Frameworks.

Ensuring a secure bond between a framework structure and layering composite resin veneer is essential for a long-lasting dental restoration. A variety of primer systems are available to facilitate the adhesive bonding. Nevertheless, the growing preference for efficiency and simplicity in dentistry has made the one-bottle universal primers a desirable option. This study aims to compare the effectiveness of universal primers on the shear bond strength (SBS) of base metal alloy (BMA) and zirconia to layering composite resin. Each 160 BMA and zirconia 20 × 10 × 5 mm test specimen was fabricated. Eight different primers (SunCera Metal Primer, Metal Primer Z, Reliance Metal Primer, Alloy Primer, MKZ Primer, Monobond Plus, ArtPrime Plus, and Clearfil Ceramic Primer Plus) were applied to 20 specimens in each group. Subsequently, a 5 × 2 mm composite resin build-up was applied. SBS tests were performed after 24 h of water storage and after thermocycling (25,000 cycles, 5-55 °C). On BMA, after water storage for 24 h, the bond strength values ranged from 26.53 ± 3.28 MPa (Metal Primer Z) to 29.72 ± 2.00 MPa (MKZ Primer), while after thermocycling, bond strength values ranged from 25.19 ± 1.73 MPa (MKZ Primer) to 27.69 ± 2.37 MPa (Clearfil Ceramic Primer Plus). On a zirconia base, after 24 h, the bond strengths values ranged from 22.63 ± 2.28 MPa (Reliance Primer) to 29.96 ± 2.37 MPa (MKZ Primer) and from 23.77 ± 3.86 MPa (Metal Primer Z) to 28.88 ± 3.09 MPa (Monobond Plus) after thermocycling. While no significant difference in bond strength was found between the primers on the BMA base, five primer combinations differed significantly from each other on zirconia (p = 0.002-0.043). All primers achieved a bond strength greater than 23 MPa on both framework materials after thermocycling. Thus, all primers tested can be applied to both framework materials with comparable results.

Effectiveness of Individual Oral Health Care Training in Hospitalized Inpatients in Geriatric Wards.

OBJECTIVE: To investigate the effectiveness of individual oral health care training (IndOHCT) on dental plaque removal and denture cleaning in hospitalized geriatric inpatients. BACKGROUND: The literature reveals neglect of hygiene and oral care in people aged over 65 years, especially in persons in need of care. Hospitalized geriatric inpatients have poorer dental health than those non-hospitalized. Furthermore, the existing literature reporting on oral healthcare training interventions for hospitalized geriatric inpatients is scarce. MATERIALS AND METHODS: This pre-post-controlled intervention study dichotomized 90 hospitalized geriatric inpatients into an intervention group (IG) and a control group (CG). Inpatients in the IG received IndOHCT. Oral hygiene was assessed using the Turesky modified Quigley-Hein index (TmQHI) and the denture hygiene index (DHI), at baseline (T0), at a second examination (T1a), and after supervised autonomous tooth brushing and denture cleaning (T1b). The influence of the Mini Mental State Examination (MMSE), Geriatric Depression Scale (GDS), and Barthel Index (BI) scores on oral hygiene was examined. RESULTS: There was no significant plaque reduction on teeth or dentures between T0 and T1a in either group. Between T1a and T1b, plaque reduction on the teeth was more effective in the IG than in the CG (p < 0.001). Inpatients with 1-9 remaining teeth removed significantly more dental plaque than inpatients with 10 or more remaining teeth. Inpatients with lower MMSE scores (p = 0.021) and higher age (p = 0.044) reached higher plaque reduction on dentures. CONCLUSIONS: IndOHCT improved oral and denture hygiene in geriatric inpatients by enabling them to clean their teeth and dentures more effectively.

Wear pattern-associated color stability of prefabricated composite veneers versus ceramic veneers.

PURPOSE: To evaluate the effect of different surface wear patterns on the discoloration tendency of two different prefabricated composite veneers and lithium disilicate ceramic veneers. MATERIALS AND METHODS: Discoloration tendency of two prefabricated composite resin veneers (Visalys Veneer Chairside (VIS) and Componeer (COM)) were compared to lithium disilicate veneers (IPS) in vitro. For each material, n = 60 samples were allocated to different test groups, and therefore each n = 10 specimens per group went through different wear tests. Mechanical abrasion tests were conducted using a toothbrush simulator, while erosive effects were carried out by citric acid (pH 1.57). A combination of abrasion and erosion tests was conducted as well. Four groups of wear tests were implemented: (1) abrasion, (2) abrasion followed by erosion, (3) erosion, and (4) erosion followed by abrasion. Another group was stored in distilled water as the control and one group was stained without a prior wear test. The staining solution was made from a coffee-tobacco brew. Specimens were stored in the coffee-tobacco solution for 21 days. Color measurements were performed with VITA Easyshade. To evaluate intramaterial discoloration, one half of every specimen was protected with foil. After storage in the staining solution, the first measurement was carried out on the 'protected' (untreated) surface, followed by a second measurement on the 'processed' (treated) discolored surface. Euclidean distance (ΔE) of discoloration was calculated according to the CIE-L*C*h* system. Data were analyzed with ANOVA followed by Games-Howell post hoc test and paired t-test (α = 0.05). RESULTS: Highest changes in ΔE were found in COM after 'abrasion' (ΔE -2.55) and 'erosion followed by abrasion' (ΔE -1.41). The discoloration tendency of VIS was affected by all wear tests, but changes were below the perceptive threshold (ΔE -0.19-0.32). Only abrasion followed by erosion affected the discoloration of IPS significantly, but findings were below the perceptive threshold, as well (ΔE -0.09). CONCLUSIONS: Prefabricated composite resin veneers revealed a low level of discoloration tendency after different wear tests. Nevertheless, in most cases the lowest discoloration tendency was found in specimens made from lithium disilicate.

Comparison of Wear Resistance of Prefabricated Composite Veneers Versus Ceramic and Enamel.

PURPOSE: To measure surface roughness before and after wear-tests of two different prefabricated composite veneers and compare them to ceramic veneers and human dental enamel. MATERIALS AND METHODS: Roughness (Ra-values) of two prefabricated composite veneers (Visalys Veneer Chairside (VIS) and Componeer (COM)) were compared to lithium disilicate Veneers (e.max CAD) and dental enamel (DENT) in vitro. In total n = 45 specimens per material and enamel samples were used for wear-tests. Wear-out tests were conducted by abrasion tests with a toothbrush simulator (22,000 strokes/ 100 g load; approximately equal to two years of cleansing) and erosion tests were carried out using citric acid (pH 1.57). Ra- and Sa-values were detected by white light interferometer before and after wear-tests. Data were analyzed with ANOVA followed by Games-Howell post hoc test and t-test (α = 0.05). RESULTS: At baseline the lowest Ra- and Sa-values were found in VIS (Ra: 0.01 µm; Sa: 0.04 µm) while DENT revealed significantly higher surface roughness (Ra: 0.11 µm, p < 0.05; Sa: 0.30, p = 0.186). COM had significantly higher Ra-values (Ra: 0.10 µm; Sa: 0.22 µm) after abrasion, while e.max CAD was most resistant to the treatments (Ra: 0.01 µm, p < 0.05; Sa: 0.05 µm, p < 0.05). Compared to DENT all veneers were significantly less affected by citric acid (p < 0.001). CONCLUSIONS: Prefabricated composite veneers have demonstrated less wear after abrasion and erosion tests compared to DENT, nevertheless, they revealed more wear compared to e.max CAD.