An in vivo comparison between a visible light-cured bonding system and a chemically cured bonding system

Objective: To comparatively assess clinical failure rate of brackets cured with two different photopolymerization sources after nine months of orthodontic treatment. Materials and Methods: The sample of this study comprised 30 patients who received comprehensive orthodontic treatment by means of fixed appliances. Using the same adhesive, 600 stainless steel brackets were directly bonded and light cured for 10 seconds with the light-emitting diode (LED) lamp or for 20 seconds with the conventional halogen lamp. A split-mouth design randomly alternated from patient to patient was applied. Failure rates were recorded for nine months and analyzed with Pearson 2 test, and log-rank test at ␣ ϭ .05 level of significance. Results: The overall failure rate recorded with the halogen unit (3.33%) was not significantly different from the failure rate for the LED lamp (5.00%). Significantly more failures were found in boys compared with girls, in the mandibular dental arch compared with the maxillary arch, and in posterior segments compared with anterior segments. However, no significant difference was found between the right and left segments. Conclusion: Both light-curing units showed sufficiently low bond failure rates. LED curing units are an advantageous alternative to conventional halogen sources in orthodontics because they enable a reduced chair-time bonding procedure without significantly affecting bond failure rate.

Section: Discussionmentioning

confidence: 75%

Section: Discussionmentioning

confidence: 99%

Clinical Evaluation of Bracket Bonding Using Two Different Polymerization Sources

Koupis¹,

Eliades

Athanasiou

2008

“…25,29,30 The only statistically significant results obtained were a smaller percentage of detachments in the maxillary arch with respect to the mandibular arch and a difference between the number of detachments in the anterior part (incisors and canines) with respect to the posterior section (premolars) of each arch. In particular, in the maxillary arch, the percentage of detachments in the anterior zones was greater than that recorded in the posterior sectors.…”

Section: Discussionmentioning

confidence: 94%

LED vs Halogen Light-Curing of Adhesive-Precoated Brackets

Mirabella

Spena

Scognamiglio³

et al. 2008

Objective: To test the hypothesis that bonding with a blue light-emitting diode (LED) curing unit produces no more failures in adhesive-precoated (APC) orthodontic brackets than bonding carried out by a conventional halogen lamp. Materials and Methods: Sixty-five patients were selected for this randomized clinical trial, in which a total of 1152 stainless steel APC brackets were employed. In order to carry out a valid comparison of the bracket failure rate following use of each type of curing unit, each patient's mouth was divided into four quadrants. In 34 of the randomly selected patients, designated group A, the APC brackets of the right maxillary and left mandibular quadrants were bonded using a halogen light, while the remaining quadrants were treated with an LED curing unit. In the other 31 patients, designated group B, halogen light was used to cure the left maxillary and right mandibular quadrants, whereas the APC brackets in the remaining quadrants were bonded using an LED dental curing light. The bonding date, the type of light used for curing, and the date of any bracket failures over a mean period of 8.9 months were recorded for each bracket and, subsequently, the chi-square test, the Yates-corrected chi-square test, the Fisher exact test, KaplanMeier survival estimates, and the log-rank test were employed in statistical analyses of the results. Results: No statistically significant difference in bond failure rate was found between APC brackets bonded with the halogen light-curing unit and those cured with LED light. However, significantly fewer bonding failures were noted in the maxillary arch (1.67%) than in the mandibular arch (4.35%) after each light-curing technique. Conclusions: The hypothesis cannot be rejected since use of an LED curing unit produces similar APC bracket failure rates to use of conventional halogen light, with the advantage of a far shorter curing time (10 seconds).

“…When orthodontic brackets are bonded by light-polymerizing composites, working time is increased, brackets may be positioned more correctly, curing depth is maximized, porosity is less, and the clinician has enough time to clean the composite around the base of the bracket, decreasing the possibility of enamel demineralization through plaque accumulation. 1 Although the most common method of delivering blue light to cure light-activated composite material is through a quartz-tungsten-halogen light-curing unit (LCU), 2 these devices have several disadvantages, [2][3][4] including relatively longer curing times (40 to 60 seconds). 5 Light-emitting diode (LED) technology has been proposed to overcome the shortcomings of standard quartz-tungsten-halogen-visible LCUs.…”

Section: Introductionmentioning

confidence: 99%

Effect of short curing times with a high-intensity light-emitting diode or high-power halogen on shear bond strength of metal brackets before and after thermocycling

Çerekja¹,

Çakırer²

2011

Objective: To test the hypothesis that short curing times using a high-intensity light-emitting diode (LED) or high-power halogen are not associated with compromised shear bond strength (SBS) of metal brackets before and after thermocycling. Materials and Methods: Two hundred forty extracted human premolar teeth were divided into six groups of 40 each. Metal brackets were bonded using a light-cured composite (Transbond XT). In group 1 a conventional halogen light (Hilux) was used for 40 seconds. In groups 2, 3, and 4 a highpower halogen light (Swiss Master) was used for 2, 3, and 6 seconds, respectively. In groups 5 and 6 a high-intensity LED (Bluephase) was used for 10 and 20 seconds, respectively. After bonding, half of the specimens in each group were thermocycled, and all specimens were tested for SBS. After debonding, the bracket bases and the enamel surfaces were scored according to the Adhesive Remnant Index. Results: Two-way analysis of variance detected significant differences in SBS values with respect to curing method (type of light-curing unit and curing time) (P 5 .0001) and thermocycling (P 5 .01). Tukey post hoc analysis showed that with or without thermocycling the mean SBS values of groups 1, 4, 5, and 6 were not significantly different, whereas group 2 showed the lowest SBS values. The predominant failure site for groups 2 and 3 was between the bracket and the adhesive and for groups 4, 5, 6 it was at the tooth/adhesive interface. Conclusion: Curing time can be reduced to 6 seconds with high-power halogen light and to 10 seconds with high-intensity LED without compromising in vitro SBS of metal brackets. (Angle