Protetik Diş Tedavisi Bölümü Koleksiyonu

Colour stability of sectional laminate veneers: A laboratory study

Fri, 01 Jan 2021 00:00:00 GMT

Colour stability of sectional laminate veneers: A laboratory study Elter, Bahar; Aladağ, Akın; Çömlekoğlu, Muharrem Erhan; Çömlekoğlu, Mine Dündar; Kesercioğlu, Atilla İsmail Background: This study aimed to evaluate the colour stability of sectional laminate veneers (SLVs) fabricated with four and cemented with two different materials. Methods: Eighty SLVs were prepared with a thickness of 0.2-0.4 mm from IPS e.max CAD, Lava Ultimate, CEREC Blocs, and IPS InLine and were cemented with Variolink Veneer and Variolink N to form 8 groups (n:10). After cementation, specimens underwent 5000 thermocyles prior to immersion in a coffee solution. Results: Colour change before and after thermal cycling did not reveal significant differences (P>0.05). After coffee immersion, significant colour change was observed in all groups (P>0.05). Only IPS InLine cemented with Variolink Veneer was considered clinically acceptable (ΔE<3.3). According to observer scorings, marginal discolouration was higher in Lava Ultimate, while no discolouration was observed in IPS InLine. Dual or lightcuring resin cements showed insignificant differences. Conclusions: SLVs fabricated with different aesthetic materials underwent perceptible (ΔE > 3.3) discolouration except for the IPS InLine cemented with light-curing resin cement. Cementation with either dualcuring or light-curing resin cements does not by itself affect colour stability. The highest marginal discolouration was in the Lava Ultimate group while no discolouration was detected in the IPS InLine group.

Retention of luting agents used for implant-supported restorations: A comparative In-Vitro study

Wed, 01 Jan 2020 00:00:00 GMT

Retention of luting agents used for implant-supported restorations: A comparative In-Vitro study Aladağ, Akın; Şahan, Makbule Heval; Ozdemir Akkus, Niler; Tüzünsoy Aktaş, Rahime Aims: The aim of this study was to compare the retention of different luting agents used with implant-supported restorations. Materials and Methods: A total of 90 custom metal frameworks and copings were prepared and divided into six different luting agent groups (n = 15/group): polycarboxylate cement (PC), resin-modified glass-ionomer cement (RMGIC), two self-adhesive resin cements (SARC), copper-ion zinc-phosphate cement (CZPC), and non-eugenol temporary resin cement (TRC). After sandblasting with 50 mu m Al2O3, the copings were cemented on frameworks and stored in artificial saliva for 48 h at 37 degrees C and thermocycled between 5-55 degrees C for 37,500 cycles. Samples were subjected to tensile testing by a universal testing machine, and data were statistically analyzed. Results: The differences between the retention values of types of cement were significant (P < 0.05). The maximum retention value was calculated for CZPC (755,12 +/- 55 MPa) while the lowest value was for TRC (311,7 +/- 61 Mpa). Conclusion: Neither of the tested cement had superiority over another to ensuring retention. The types of cement presented were meant to be a discretionary guide for the clinician in deciding the amount of the desired retention between castings and abutments. WOS: 000565286100008; PubMed ID: 32788484