- Email: [email protected]
Curing efficiency of self-etching, self-adhesive resin cements
Table 3.—Results of the Three-Way Factorial ANOVA, Dependent Variable: Axial Tensile Strength Effect
Post Surface treatment Storage condition Post * Surface treatment Post * Storage condition Surface treatment * Storage condition Post * Surface treatment * Storage condition Error
SS
d.f.
ms
F
p
1142185.32 421813.74 256631.72 123937.89 46755.49 121500.1 54257.348 826129.85
2 2 2 4 4 4 8 241
571092.66 210956.87 128315.86 30984.47 11688.87 30375.02 6782.17 2598.05
219.82 81.20 49.39 11.93 4.50 11.69 2.61 –
0.0001 0.0001 0.0001 0.0001 0.0016 0.0001 0.0093 –
(Courtesy of Sahafi A, Peutzfeldt A: Durability of the bond between resin composite cores and prefabricated posts. Acta Odont Scand 67:271-276, 2009.)
Sahafi A, Peutzfeldt A: Durability of the bond between resin composite cores and prefabricated posts. Acta Odont Scand 67:271-276, 2009
Reprints available from A Sahafi, Dept of Oral Rehabilitation, School of Dentistry, Univ of Copenhagen, No¨rre Alle´ 20, DK-2200 Copenhagen N, Denmark; fax: þ45 35326505; e-mail: [email protected]
Curing efficiency of self-etching, self-adhesive resin cements Background.—Resin cements are extremely useful in cementing fixed prostheses, but have the drawback of being technique-sensitive, which complicates clinical procedures, increases the time needed for cementation, and makes adhesion susceptible to manipulation errors. To address these problems, self-etching, self-adhesive resin cements have been developed. Not all of the properties of these new cements have been well-studied. An investigation focusing on the degree of cure (%DC) of specific self-etching, self-adhesive resin cements compared to conventional resin cement was conducted in self- and dualcuring modes. Methods.—Twelve specimens of four different self-etching, self-adhesive resin cements were prepared, with six used to assess %DC and six used to assess the chemical activation mode in the %DC. The four self-etching, self-adhesive materials were RelyX Unicem (RXU), Maxcem (MXC), Biscem (BCM), and Multilink Sprint (MLS); the classic resin cement tested was Multilink Automix (MLA). Six specimens of each material were dual cured, irradiated for 20 seconds with a halogen light curing unit, and left to rest for 5 minutes. Six other specimens were self-cured, not irradiated, and left in dark, dry conditions for 10 minutes. Micro-attenuated total reflectance Fourier transform infrared spectrometry (ATR FTTR spectrometry) was used to assess %DC. Results.—The highest %DC in the self-curing mode was demonstrated by MLS and differed significantly from all the other materials, which had similar %DC values. However,
70
Dental Abstracts
the %DC values were very low, between 10.82% and 24.93%. Similarly, low values were found for the dual-curing mode, ranging from 26.40% to 41.52%. MLA had the highest %DC of all the materials and MXC the lowest. The difference between MXC and the others was statistically significant. RXU, BCM, and MLS yielded statistically similar results. The two curing modes demonstrated statistically significant differences in %DC values. In each case, the %DC was higher for dual-cured materials (Fig 1). Discussion.—The %DC values were quite low, which may indicate problems for clinical applications of these materials. With increased irradiation times, the %DC could potentially be increased, assuming the light is not blocked by an overlying restoration.
Fig 1.—Comparison of the %DC between self-cured and dualcured groups per material. (Courtesy of Vrochari AD, Eliades G, Hellwig E, et al: Curing efficiency of four self-etching, self-adhesive resin cements. Dent Materials 25:1104-1108, 2009.)
Clinical Significance.—These results indicate that all the materials may show inadequate initial strength when light is not likely to reach the cement. This would include use for endodontic posts, metal-ceramic or all-ceramic opaque restorations, or inlays that are thicker than usual. For dual-cured situations without light attenuation, MLA was the best choice. The applications for these materials will always involve an overlying restoration that will produce some light attenuation, so %DC values may remain inadequate. More studies are needed to examine all the contributing factors.
Vrochari AD, Eliades G, Hellwig E, et al: Curing efficiency of four selfetching, self-adhesive resin cements. Dent Materials 25:1104-1108, 2009 Reprints available from AD Vrochari, Klinikum der Albert-LudwigsUniversita¨t, Universita¨tsklinik fu¨r Zahn-, Mund- und Kieferheilkunde, Abteilung fu¨r Zahnerhaltungskunde und Parodontologie, Hugstetter Str 55, D-79106 Freiburg i Br, Germany; fax: þ49 761 270 4762; e-mail: [email protected], areti-dimitra.vrochari@ uniklinik-freiburg.de
Endodontics Rubber dam use Background.—Rubber dam use during root canal treatment offers control of cross-infection; protection from aspiration or swallowing of instruments, medications, irrigating solutions, or debris and from injury caused by instruments, medications, or manual manipulation; and improved treatment efficiency. It is the accepted standard of care by professional organizations around the world and is taught in dental school. However, many practicing dentists ignore the use of rubber dam for procedures. Issues accompanying
rubber dam use and strategies for improving its application were explored. Methods.—Data were compiled through a literature search of the PubMed database, which identified 48 relevant articles. Results.—Worldwide, undergraduate dental students indicate that they are highly likely to place rubber dams
Table 5.—Patients’ Judgement of Their Current Experience (CE) and Their Future Preference (FP) For Treatment With Rubber Dam CE (%) Reference
Operator
Nelson (1979) Dentist Jones & Reid (1988) UGS
Procedure
Positive
DP – OP, Endo, Bleaching Most patients reported low anxiety level GDP Endo, Rest, FS The ratio of favourable to Gergely (1989)a unfavourable comments was 8 : 3 UGS Endo, Rest, BC 58 (55.9) Stewardson Endo, Rest 78 (80.6) & McHugh (2002)b GDP Filipovic´ et al. (2004) UGS Endo 58.2 Specialist Endo Go¨rduysus (2006) UGS Endo 47.2 PGS Endo 67.4
FP(%) Negative
–
Yes
No preference
85 30
49
15 21
72.2 (73.8) 19.4 (19.1) 42 (44.1) 43 (47.1) 22 (19.4) 70 (72.2) 41.8 63 76 52.8 46.2 32.6 77.2
No
44 (41.2) 26 (22.2) 37 12 23.6 4.3
8.3 (7.1) 13 (11.8) 4 (5.6) 0 12 30.2 18.5
Abbreviations: GDP, General dental practitioner; UGS, undergraduate student; PGS, postgraduate student; DP, dental procedures; OP, operative procedures; Endo, endodontic treatment; Rest, restorations; FS, fissure sealant; BC, bridge cementation. (Courtesy of Ahmad IA: Rubber dam usage for endodontic treatment: A review. Int Endodont J 42:963-972, 2009.) a Figures shown in the parentheses represent the opinion of the patients who received endodontic treatment only. b Figures shown in the parentheses represent the opinion of the patients who received endodontic treatment only The data was kindly provided by Dr Dominic Stewardson (personal communication, November 2008).
Volume 55
Issue 2
2010
71
Post Surface treatment Storage condition Post * Surface treatment Post * Storage condition Surface treatment * Storage condition Post * Surface treatment * Storage condition Error
SS
d.f.
ms
F
p
1142185.32 421813.74 256631.72 123937.89 46755.49 121500.1 54257.348 826129.85
2 2 2 4 4 4 8 241
571092.66 210956.87 128315.86 30984.47 11688.87 30375.02 6782.17 2598.05
219.82 81.20 49.39 11.93 4.50 11.69 2.61 –
0.0001 0.0001 0.0001 0.0001 0.0016 0.0001 0.0093 –
(Courtesy of Sahafi A, Peutzfeldt A: Durability of the bond between resin composite cores and prefabricated posts. Acta Odont Scand 67:271-276, 2009.)
Sahafi A, Peutzfeldt A: Durability of the bond between resin composite cores and prefabricated posts. Acta Odont Scand 67:271-276, 2009
Reprints available from A Sahafi, Dept of Oral Rehabilitation, School of Dentistry, Univ of Copenhagen, No¨rre Alle´ 20, DK-2200 Copenhagen N, Denmark; fax: þ45 35326505; e-mail: [email protected]
Curing efficiency of self-etching, self-adhesive resin cements Background.—Resin cements are extremely useful in cementing fixed prostheses, but have the drawback of being technique-sensitive, which complicates clinical procedures, increases the time needed for cementation, and makes adhesion susceptible to manipulation errors. To address these problems, self-etching, self-adhesive resin cements have been developed. Not all of the properties of these new cements have been well-studied. An investigation focusing on the degree of cure (%DC) of specific self-etching, self-adhesive resin cements compared to conventional resin cement was conducted in self- and dualcuring modes. Methods.—Twelve specimens of four different self-etching, self-adhesive resin cements were prepared, with six used to assess %DC and six used to assess the chemical activation mode in the %DC. The four self-etching, self-adhesive materials were RelyX Unicem (RXU), Maxcem (MXC), Biscem (BCM), and Multilink Sprint (MLS); the classic resin cement tested was Multilink Automix (MLA). Six specimens of each material were dual cured, irradiated for 20 seconds with a halogen light curing unit, and left to rest for 5 minutes. Six other specimens were self-cured, not irradiated, and left in dark, dry conditions for 10 minutes. Micro-attenuated total reflectance Fourier transform infrared spectrometry (ATR FTTR spectrometry) was used to assess %DC. Results.—The highest %DC in the self-curing mode was demonstrated by MLS and differed significantly from all the other materials, which had similar %DC values. However,
70
Dental Abstracts
the %DC values were very low, between 10.82% and 24.93%. Similarly, low values were found for the dual-curing mode, ranging from 26.40% to 41.52%. MLA had the highest %DC of all the materials and MXC the lowest. The difference between MXC and the others was statistically significant. RXU, BCM, and MLS yielded statistically similar results. The two curing modes demonstrated statistically significant differences in %DC values. In each case, the %DC was higher for dual-cured materials (Fig 1). Discussion.—The %DC values were quite low, which may indicate problems for clinical applications of these materials. With increased irradiation times, the %DC could potentially be increased, assuming the light is not blocked by an overlying restoration.
Fig 1.—Comparison of the %DC between self-cured and dualcured groups per material. (Courtesy of Vrochari AD, Eliades G, Hellwig E, et al: Curing efficiency of four self-etching, self-adhesive resin cements. Dent Materials 25:1104-1108, 2009.)
Clinical Significance.—These results indicate that all the materials may show inadequate initial strength when light is not likely to reach the cement. This would include use for endodontic posts, metal-ceramic or all-ceramic opaque restorations, or inlays that are thicker than usual. For dual-cured situations without light attenuation, MLA was the best choice. The applications for these materials will always involve an overlying restoration that will produce some light attenuation, so %DC values may remain inadequate. More studies are needed to examine all the contributing factors.
Vrochari AD, Eliades G, Hellwig E, et al: Curing efficiency of four selfetching, self-adhesive resin cements. Dent Materials 25:1104-1108, 2009 Reprints available from AD Vrochari, Klinikum der Albert-LudwigsUniversita¨t, Universita¨tsklinik fu¨r Zahn-, Mund- und Kieferheilkunde, Abteilung fu¨r Zahnerhaltungskunde und Parodontologie, Hugstetter Str 55, D-79106 Freiburg i Br, Germany; fax: þ49 761 270 4762; e-mail: [email protected], areti-dimitra.vrochari@ uniklinik-freiburg.de
Endodontics Rubber dam use Background.—Rubber dam use during root canal treatment offers control of cross-infection; protection from aspiration or swallowing of instruments, medications, irrigating solutions, or debris and from injury caused by instruments, medications, or manual manipulation; and improved treatment efficiency. It is the accepted standard of care by professional organizations around the world and is taught in dental school. However, many practicing dentists ignore the use of rubber dam for procedures. Issues accompanying
rubber dam use and strategies for improving its application were explored. Methods.—Data were compiled through a literature search of the PubMed database, which identified 48 relevant articles. Results.—Worldwide, undergraduate dental students indicate that they are highly likely to place rubber dams
Table 5.—Patients’ Judgement of Their Current Experience (CE) and Their Future Preference (FP) For Treatment With Rubber Dam CE (%) Reference
Operator
Nelson (1979) Dentist Jones & Reid (1988) UGS
Procedure
Positive
DP – OP, Endo, Bleaching Most patients reported low anxiety level GDP Endo, Rest, FS The ratio of favourable to Gergely (1989)a unfavourable comments was 8 : 3 UGS Endo, Rest, BC 58 (55.9) Stewardson Endo, Rest 78 (80.6) & McHugh (2002)b GDP Filipovic´ et al. (2004) UGS Endo 58.2 Specialist Endo Go¨rduysus (2006) UGS Endo 47.2 PGS Endo 67.4
FP(%) Negative
–
Yes
No preference
85 30
49
15 21
72.2 (73.8) 19.4 (19.1) 42 (44.1) 43 (47.1) 22 (19.4) 70 (72.2) 41.8 63 76 52.8 46.2 32.6 77.2
No
44 (41.2) 26 (22.2) 37 12 23.6 4.3
8.3 (7.1) 13 (11.8) 4 (5.6) 0 12 30.2 18.5
Abbreviations: GDP, General dental practitioner; UGS, undergraduate student; PGS, postgraduate student; DP, dental procedures; OP, operative procedures; Endo, endodontic treatment; Rest, restorations; FS, fissure sealant; BC, bridge cementation. (Courtesy of Ahmad IA: Rubber dam usage for endodontic treatment: A review. Int Endodont J 42:963-972, 2009.) a Figures shown in the parentheses represent the opinion of the patients who received endodontic treatment only. b Figures shown in the parentheses represent the opinion of the patients who received endodontic treatment only The data was kindly provided by Dr Dominic Stewardson (personal communication, November 2008).
Volume 55
Issue 2
2010
71