Influence of Arabic Qahwa Beverage on Optical and Mechanical Properties of Lithium Disilicate Glass Ceramics and Zirconia Restorative Materials.

AIMS: The study aims to assess the effect of Arabic Qahwa (AQ) on the color parameters of lithium disilicate glass ceramic (LDGC), IPS e.max computer-aided design (CAD), and multilayered zirconia CAD/ computer-aided manufacturing (CAM) ceramic materials after immersion in AQ and also, to measure the biaxial fracture strength and fracture modes of the tested materials. MATERIALS AND METHODS: Sixty circular specimens were milled from LDGC and zirconia. Before AQ immersion, the color parameters of the specimens L, a, and b were measured and recorded using a spectrophotometer on white, black, and gray background and analyzed after AQ staining and aging for 14 days. Biaxial compressive forces and fracture types were recorded. The collected data were analyzed with SPSS for descriptive statistics, one-way analysis of variance, and post hoc tests. RESULTS: The overall TP values were 16.79 and 15.85 for LDGC and zirconia, respectively. The recorded ΔE* values were 2.63 and 2.99 for LDGC and zirconia, which have no remarkable difference. The TP values after AQ staining were slightly lesser. Subgroup analysis revealed considerable differences in TP values among zirconia specimens under both backgrounds, whereas substantial differences in ΔE* values were observed between LDGC and zirconia under white background only. Lithium disilicate glass ceramic (LDGC) had higher biaxial fracture forces than zirconia. Reparable, semi-reparable, and non-reparable fractures comprised 60, 30, and 10% of the overall fracture modes, respectively, with significant differences between and within groups (p = 0.034). CONCLUSION: AQ staining had a marked effect on the TP and ΔE* values of the tested CAD/CAM materials, but the values were within clinically acceptable levels. The optical properties were dependent on the material. Lithium disilicate glass ceramic (LDGC) had higher biaxial fracture forces than zirconia. Reparable fracture was the dominant type among the examined materials. CLINICAL SIGNIFICANCE: Glazed surface for any CAD/CAM ceramic prostheses is highly recommended. Both tested materials are strongly recommended to be used for AQ consumers.

Effects of the Cervical Marginal Relocation Technique on the Marginal Adaptation of Lithium Disilicate CAD/CAM Ceramic Crowns on Premolars.

AIM AND OBJECTIVE: To evaluate the effect of cervical margin relocation (CMR) for crowns designed using CAD/CAM technology and fabricated from lithium disilicate (e.max, CAD) before and after aging; and to compare the fracture forces and failure type of the tested crowns. MATERIALS AND METHODS: Mesio-occluso-distal(MOD) cavities 1 mm above the cementoenamel junction(CEJ) were prepared on 40 maxillary first premolars. The teeth were divided into four groups. In group A, all cervical margins (CM) were located 1 mm above the CEJ. However, in both mesial and distal proximal boxes of groups B, C, and D, in addition to the MOD cavities, the CMs were extended 2 mm on both sides below the CEJ apically to simulate the CMR technique. In group B, the mesial and distal proximal boxes were filled with flowable composite, while for group C and group D, specimens were filled with composite resin fillings. To simulate the CMR technique, the cavities were filled with composite layers of 3 mm in two increments. Using the CAD/CAM system, 40 standard crowns were prepared on premolars, then cemented using a dual-curing adhesive cement. Assessments of the marginal integrity of interfaces of the proximal boxes of the cemented crowned teeth were recorded. Statistical differences between groups were analyzed using the ANOVA and Bonferroni's posthoc test. RESULTS: The first null hypothesis was accepted since no statistically significant differences were found in marginal integrity before and after aging (p>0.05), while the second was partially rejected since different fractured force values were recorded and a significant difference was detected between group D and group B. The third hypothesis was rejected because the catastrophic fracture rate was the highest among the four groups. CONCLUSION: The implementation of CMR before and after aging had a good effect on the marginal integrity of CM relocation. The CMR technique with resin luting cement of lithium disilicate crowns is effective and recommended for the restoration in deep proximal boxes of premolars or posterior teeth. CLINICAL SIGNIFICANCE: CAD/CAM-generated e. max all-ceramic crowns with composite as the CMR enable the reconstruction of severely destroyed teeth irrespective of the position of the cavity margins.

Impacts of the Triple bristles three-sided sonic powered toothbrush on tooth shade, plaque control and gingival health.

OBJECTIVES: To evaluate the efficacy of the Triple bristles three-sided sonic powered toothbrush in plaque removal and its impact on tooth shade and gingival health, and to compare this with a conventional manual toothbrush. METHODS: Fifty two participants (26 males and 26 females; mean age [SD] = 22.48 [1.52], SE = 0.210, 95% CI = 22.06-22.90) were recruited into this controlled within-subject, randomized, two-treatment, 1-month crossover and examiner-blinded observational study between October 2020 and January 2021 in the School of Dentistry, University of Jordan. Within each participant, the upper and lower jaws were randomized to receive a brushing protocol either with the Triple bristles three-sided sonic brush or with a soft manual standard toothbrush with flat trimmed bristles. Tooth shades were recorded for upper and lower anterior and premolar teeth. The Turesky-Modified Quigley-Hein Plaque Index (TMQHPI) and bleeding on probing (BOP) were evaluated at study baseline, 1 week and 1 month after applying the brushing protocol. RESULTS: Both tested brushes were associated with significant reduction in plaque scores and BOP (p < 0.05). The Triple bristles brush was more effective in reduction in plaque and BOP in the lower jaw and among females than the manual brush (p < 0.05). CONCLUSIONS: The Triple bristles brush was more superior for reduction in plaque and probing on bleeding in the lower jaw and among females.

Treatment of symptomatic, deep, almost cariously exposed lesions using ozone.

The aim of this controlled randomized crossover study was to assess post-treatment pain and the need for root canal treatment after the use of a traditional caries removal method followed by restoration, or after an ozone method of more conservatively managing the deep caries and a restoration. 84 participants (42 males and 42 females, mean age ± SD = 23.9 ± 2.0 years) were randomly allocated to receive either a traditional (n = 42, 21 males and 21 females) or ozone (n = 42, 21 males and 21 females) method. The ozone method only differed from the traditional method by leaving the deep leathery caries on the pulpal floor and then treating this with 20 s of ozone from the healozone X4 (Curozone, Germany). All caries was removed in the traditional group. A conventional glass ionomer cement (Riva Self Cure High Viscosity, SDI, Australia) was placed followed by a bonded composite resin restoration (Filtek Z250 Universal Restorative, 3 M ESPE, USA) in each cavity. The visual analogue scale was used to assess pain scores before treatment and after 24 h. The participants were then followed up for 2 years to assess the need for root canal treatment. Statistical significance levels were set at α ≤ .05. Both groups were associated with significant reduction of pain scores 24 h after treatment (p < .0001). The ozone treatment was associated with less pain 24 h after treatment (p < .0001) and less need for root canal treatment (p = .014), after 2 years follow up, than the conventional treatment. In conclusion, treatment of symptomatic, deep carious lesions by ozone following partial removal of caries was accompanied with less pain and occurrence of RCT after treatment compared to traditional complete caries removal.