Innovative light-curable calcium phosphate cements as retrograde filling material

Innovative light-curable calcium phosphate cements as retrograde filling material

d e n t a l m a t e r i a l s 3 0 S ( 2 0 1 4 ) e1–e180 209 Assessing appearance in human dental color space S. Brazzoli ∗ , G. Ciampalini, D. Don, E...

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d e n t a l m a t e r i a l s 3 0 S ( 2 0 1 4 ) e1–e180

209 Assessing appearance in human dental color space S. Brazzoli ∗ , G. Ciampalini, D. Don, E. Nembrini, A. Cerutti University of Brescia, Department Restorative Dentistry, Italy Purpose: The aim of this study was to determine the color subspace of all possible appearances containing every possible tooth color and then define the color difference (DE) perceived by the human observer. Methods and materials: The tooth color subspace has been determined through visual assessment by experts, starting from shade guides VITA Classical Shade Guide and VITA 3D Master. Once the color subspace was determined, we have printed samples of the central axes of this subspace according to the Munsell Color Order System. On a visually neutral background several observers have been asked to order patches according to hue (H), chroma (C) and lightness (V), one axes at the time. Results: The average difference (DE), using various color difference measures, along each subspace axis was determined. DM is the L2 distance in the Munsell space, DE is the Euclidean distance in the CIELAB space, DE94 is the CIE 1994 color difference and the DE2000 is the CIEDE2000 color difference. The Hseq DE = 0.895 or a DE94 = 0.673 or DE2000 = 0.804, the Vseq DE = 0.851, DE94 = 0.659 and DE2000 = 0.552 and for the Cseq the values are DE = 1.4, DE94 = 0.783 and DE2000 = 0.794. DE94 is a color perceptual distance almost uniform along all axes so we use as general criterion DE94 = 0.65 as color discrimination value in the whole subspace. Conclusion: This result allows for an automatic estimate of color restoration quality and provides a measurement of the average discrimination threshold in the tooth color subspace. http://dx.doi.org/10.1016/j.dental.2014.08.210 210 Postoperative sensitivity: 1-year randomized clinical trial M.H.S. Souza 1,∗ , K.G.K. Carneiro 2 , J.F. Araujo 2 , M.F. Lobato 1 , T.A.F. Barros 1 , M.F. Braga 1 , S.C. Loretto 1 , P.A.R.S. Souza 1 1 2

Federal University of Pará, Brazil Federal University of Maranhão, Brazil

Purpose: The present clinical study aimed to assess the postoperative sensitivity (POS) after seven days, 6 and 12 months in large, deep class I and II restorations bonded with six different adhesive systems. Methods and materials: The restorative procedures (n = 20) were randomly assigned and performed by two trained and experienced operators using the following systems: G1 – E&R three-step adhesive Adper SBMP (3M ESPE); G2 – E&R two-step Adper Single Bond 2 (3M ESPE); G3 – E&R two-step XP Bond (Dentsply); G4 – E&R two-step All Bond 3 + liner (BISCO Inc); G5

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– SE one-step Adper SE Plus (3M ESPE); and G6 – SE two-step All Bond SE + liner (BISCO Inc.). All preparations were restored with Filtek Z-350 nanoparticle composite resin (3M ESPE). The 120 restorations were double-blinded evaluated using slightly modified USPHS criteria to POS at baseline, seven days, six months and 1 year. The data were analyzed by the Cochran’s and Fisher exact’s tests for intragroup and intergroup analysis, respectively. Results: The POS differed significantly among G5 × G6 adhesives at seven days (p = 0.0202). The intragroup analysis showed reduced POS in G3 (p = 0.0061) and G4 (0.0259). Conclusion: All Bond 3 and XP-Bond were able to reduce the POS after 1 year. All Bond SE behaved better than Adper SE after 7 days of restoration. http://dx.doi.org/10.1016/j.dental.2014.08.211 211 Innovative light-curable calcium phosphate cements as retrograde filling material A. Abedi-Amin 1,∗ , A. Darvizeh 1 , A. Luzi 1 , R. Mongiorgi 2 , S. Sauro 1 1

Universidad CEU-Cardenal Herrera, Valencia, Spain 2 Alma Mater Studiorum, University of Bologna, Bologna, Italy Purpose: Portland cements (PC) used for root-end fillings may present humble handling characteristics, long setting time and bacteria/toxins microleakage. This study aimed at comparing the apical sealing of an experimental PC and two light-curing resin-cements subsequent to simulated body fluid (SBS) storage. The alkaline activity and the morphology/root-canal adaptation were also evaluated. Methods and materials: An ordinary PC was used as control cement and to formulate an experimental PC using titanium oxide and two phyllosilicates (sodium–calcium–aluminium–magnesium–silicate hydroxide; aluminium–magnesium–carbonate hydroxide). A resin blend based on Bis-GMA, HEMA and PMDM was used (50 wt%) to generate two light-curing cements doped (50 wt%) with calcium silicate-doped/calcium-phosphate (Hybrid-SICaPO4 ) or dicalcium-phosphate dehydrate (Hybrid-CaPO4 ). Five discs were created (1 mm × 10 mm) and the pH was monitored (30 days). Twelve single-rooted premolars were endodontically treated and obturated with gutta-percha (GP). A root-end preparation was performed and filled with the tested cements; the hybrid cements were light-cured for 1 min. The GP was removed and the specimens connected to a digital liquid flow sensor (6.9 kPa). The fluid volume and peak filtration were assessed after different periods in SBS (24, 48 h, 1, 2, 4 weeks). Statistical analysis was performed using a two-way ANOVA and Tukey’s test for multiple comparisons (P < 0.05). Three further specimens per each group were endodontically treated and obdurate as previously described. These were then sectioned into discs (1-mm) and examined trough non-destructive optical microscopy after SBS storage. Results: The light-curing cements showed the lowest peak and volume filtration after 24 h (P < 0.05); all the cements

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d e n t a l m a t e r i a l s 3 0 S ( 2 0 1 4 ) e1–e180

showed no difference after two and four weeks in SBS (P > 0.05). The highest fluid filtration volume was attained with CaPO4 (P < 0.05) after 4 weeks. The PCs maintained high alkalising activity, while the light-curing cements showed a neutral pH during the entire storage period. The cement–root dentin interfaces created using the two PCs were characterized by gaps and porosity, while SiCaPO4 and CaPO4 were devoid of important irregularities. Only SiCaPO4 showed fractures/gaps at the interface after 4 weeks in SBS; all the cements showed mineral precipitation. Conclusion: These innovative hybrid cements may be considered in endodontic surgery as alternative to conventional PCs due to their improved handling properties and early sealing ability. In particular, the hybrid-CaPO4 has greater sealing ability and marginal adaptation as well as remarkable mineral precipitation at more neutral pH. Keywords: Endodontics; Light-curing cements; Fluid filtration http://dx.doi.org/10.1016/j.dental.2014.08.212 212 Air-polishing with glycine and bicarbonate powders on restorative materials C.G. Sartori ∗ , F. Murillo-Gómez, A.B. Soares, M.F. De Goes University of Campinas, Brazil Purpose: To evaluate the effect produced by airpolishing procedure using glycine-based powder and sodium bicarbonate-based powder on different restorative materials’ surfaces. Methods and materials: A nano-filled composite resin Filtek Supreme Ultra (SU) (3M ESPE), a nano-hybrid composite resin IPS Empress direct (IPS) (Ivoclar Vivadent) and the glassceramic Vitablock Mark II (Vita) were used. Disk specimens (n = 10) were made for each material (6.5 mm × 0.5 mm). They were divided in 2 groups of 5 specimens each to be airpolished with sodium bicarbonate (BS) (Polidental, SP, Brazil) and glycine (GCP) (Clinpro Prophy Powder, 3M ESPE). The Profi Neo polishing device was used at a 5 mm working distance, for 5 s and 4 bar pressure. A profilometer (Surcoder SE 1700) working at 0.5 mm/s was employed to evaluate roughness and a scanning electron microscope (JEOL-LV 5600) was used to evaluate surface morphology. Roughness was measured in all specimens before being polished to serve as control. Post-polishing roughness values were analyzed using variance analysis and Tukey’s test (p < 0.05). Results: Group IPS-BS (0.62 ± 0.20 ␮m) showed significantly higher values than groups SU-BS (0.16 ± 0.02 ␮m) and VITA-BS (0.20 ± 0.12 ␮m). Group IPS-GCP (0.29 ± 0.13 ␮m) was significantly lower than IPS-BS but not different from SU-GCP (0.21 ± 0.09 ␮m) and VITA-GCP (0.17 ± 0.05 ␮m). There were no statistical differences between each control values and measures after submitted to air polishing. BS produced more surface alterations on IPS and SU than GCP. For VITA, the alterations produced by BS and GCP were not different between them.

Conclusion: BS produced higher roughness values on IPS. BS produced more morphological alterations on the two composite resins employed. Keywords: Air microscopy

abrasion;

Composite

resins;

Electron

http://dx.doi.org/10.1016/j.dental.2014.08.213 213 PLLA with metronidazole or amoxicillin – Alternative to systemic antibiotics T.G. Carnaval ∗ , C.A. Adde, M.M. Romano, F. Gonc¸alves, G.C. Santos, L.H. Catalani, V.E. Arana-Chavez, I.P. Tortamano, M.S. Soares University of São Paulo, Brazil Purpose: In view of the growing demand for an alternative to systemic antimicrobials prescription in Implantology, local application via polymeric devices decreases side effects and bacterial resistance. Considering the treatment of periimplantar infections, the use of polymer poly-l-lactide (PLLA) impregnated with antimicrobials, could be a favorable alternative local treatment due the ease of fabrication, structure and cytocompatibility. The objective was to compare the association of 20% metronidazole or amoxicillin to PLLA as a local alternative treatment to periimplantar infections. Methods and materials: 15 (n) polymer disks with 6 mm diameter for each group: A (amoxicillin) and M (metronidazole) were prepared by deposition (Casting). All discs were stored in a buffer solution at pH 5.0 or 7.4 and aliquots were analyzed by high performance liquid chromatography (HPLC) at 8, 24, 48, 72, 96, 120, 144 and 168 hr. Specimens were weighed after 3 and 6 months for degradation analysis. For cytocompatibility, human fibroblast viability was tested by the MTT reaction after 24, 48 and 72 h. Results: At pH 5, (A) peaked at 61% release after 144 h compared to almost 100% for (M) after 168 h of storage (p = 0.0006). At pH 7.4, (A) peaked at 50% release after 24 h, and (M) 70% after 120 h (p < 0.0001). ANOVA analysis of MTT reaction showed that A and M were different (p = 0.0314) but both were biocompatible. As for degradation in pH 5.0 (A) maintained 37% of mass after 6 months and (M) 57% (p = 0.24). And in pH 7.4 (A) 41% and (M) 73% (p = 0.19). Conclusion: The association of PLLA to (M) and (A) can be a promise local treatment in periimplantar infection considering time release, cytocompatibility and degradation characteristics. Metronidazole showed the best result concerning drug release and mass preservation. Keywords: Polymer; PLLA; Antimicrobials http://dx.doi.org/10.1016/j.dental.2014.08.214