Survival rate of indirectly bonded brackets using single vs. two-component orthodontic adhesive: A 12-month split-mouth clinical trial

Objective

Compare the bonding survival rate of two distinct bonding materials: Ortho Solo + Gradia LoFlo Resin and single component GC Ortho Connect.

Materials and Methods

Indirect bonding fixed appliance treatment was required for 26 consecutive patients, 8 males and 18 females, with a mean age of 22.1 +/- 4.2 years. All patients were treated with SWM (Straight-Wire Mirabella) technique (Sweden and Martina, Due Carrare, Padova, Italy). Each patient's bonding process followed a contralateral pattern. Firstly, a 37 % orthophosphoric acid etching gel was used for 20 s, subsequently the single or two components light-cured adhesives were applied through a split-mouth cross-arch procedure. The patients underwent a 12-month follow-up period and brackets failures were rebounded, but not further included in the study. Statistical analysis was performed to analyse the survival rate of the bonding materials and the influence of the variables, with a significant level of α = 0,05.

Results

The GC Connect group was used on 349 teeth, while the Ortho Solo + Gradia group was used on 351 teeth, and the indirect debonding rate was respectively 17.5% and 12.8%. With respect to the total sample, statistically significant values were found for both sex and dental arch. The bracket's survival rate for incisors, canines, premolars and molars was not significant. However, a higher debonding rate was clinically appreciable in upper and lower molars.

Conclusion

In a 12-months observation period, considering all maxillary and mandibular teeth the indirect survival rate for the group GC Ortho Connect and Ortho Solo + Gradia was respectively 82.5% and 87.2%. Although the difference was not significant, a pronounced tendency to debonding for the single component group was appreciable from a clinically point of view.

Bracket Failure in Orthodontic Patients: The Incidence and the Influence of Different Factors

Failure of brackets is a common problem in orthodontics. This affects the treatment time, cost, and compliance of the patient. This study was conducted to estimate the bracket failure rate and the related factors for the long term. Methodology. This ambidirectional cohort study included 150 nonsyndromic orthodontic patients undergoing fixed appliance therapy for the last two years. The same patients were followed for 7 months. Different variables related to bracket failure were evaluated. The available data were analyzed descriptively, and the Kaplan-Meier estimate was used to measure the bracket survival rate from the date of bonding to failure. Results. A total of 180 bracket bond failures in the 150 included patients (52.2% males and 47.8% females) with a median age of 17 years (range 10-25 years). 69% of brackets failures were reported within the first 6 months after bonding. About 58.3% of bracket failure was noticed in adolescent patients before the age of 18 years. The majority of the cohort (81.1%) has good oral hygiene. The failure rate in patients with normal overbite was 41.1%, in decreased overbite cases was 15%, while in deep bite cases the failure rate was 43.9% with a statistically significant difference. Adults show less bracket failure (41.7%) than adolescent patients (58.3%). More bracket failure was noted in the lower arch (55%) than the upper arch (45%), and there were more bond failures posteriorly (61%) than on the anterior teeth (39%). Majority (41.1%) of the bracket failed on round NiTi wires. Conclusion. The bracket failure rate was 6.4%, with most bracket failure occurring in the first 6 months after bonding with individual difference. There was more incidence of bond failure in an increased overbite, adolescents, lower arch, posterior teeth, and lighter alignment wires.

Failure rates among metal brackets cured with two high-intensity LED light-curing lamps: an in vivo study

OBJECTIVE

The objective of this split-mouth clinical trial was to compare bonding failure rates of metal brackets bonded with two different light-emitting diode (LED) light-curing lamps with different high-intensity power outputs.

MATERIALS AND METHODS

Forty patients were included for a total of 800 brackets that were randomly bonded (left and right sides in a 1:1 ratio) in maxillary and mandibular arches using two different LED devices. An LED of 3200 mW/cm2 and an LED of 5000 mW/cm2 were used in this split-mouth clinical trial. Bonding failures during the initial 6 months of orthodontic treatment were recorded as maxillary versus mandibular, anterior teeth versus posterior teeth, and left side versus right side.

RESULTS

Five dropouts were recorded for discontinuing orthodontic treatment and 700 brackets were analysed in total. The bonding failure rates for 3200 and 5000 mW/cm2 LEDs were 6.0 and 7.4 per cent, respectively (P = 0.450), which were not statistically significantly different. There were no significant differences in bracket survival rates between the LEDs used (P = 0.866). The posterior teeth presented a higher index of bond failures (odds ratio, 3.14; 95% confidence interval, 1.68-5.87; P < 0.001).

LIMITATIONS

Direct comparison was only done between two high-intensity LED lights rather than against conventionally used halogen lights.

CONCLUSION

Similar bonding failures were recorded using both LED devices (3200 and 5000 mW/cm2). Significantly more bonding failures occurred in premolar teeth than in anterior teeth.

A Clinical Comparison of Failure Rates of Metallic and Ceramic Brackets: A Twelve-Month Study

Objective

Clinical comparison of the survival rates between stainless steel and ceramic brackets over a 12-month period.

Materials and Methods

The study involved 20 consecutive patients with diagnosed malocclusion that required two-arch fixed appliance treatment. The participants were randomly divided into two 10-member groups. Group 1 was treated with Abzil Agile (3M Unitek) stainless steel brackets; group 2 was treated with Radiance (American Orthodontics) monocrystalline ceramic brackets. All the brackets were bonded by the same operator. Over the next 12 months, all bracket failures were recorded with each appointment. The received data were processed statistically using the Mantel–Cox test, Kaplan–Meier method, and Cox hazard model.

Results

A total of 381 brackets were bonded, 195 of which were metallic brackets and 186 were ceramic ones. In the 12-month observation period, there were 14 metal (7.2%) and 2 ceramic bracket (1.1%) failures. The overall failure rate was 4.2% (n = 16). The majority of failures (14 brackets; 87.5%) occurred during the first 6 months of the experiment, 12 (83%) of which were metal brackets and 2 (100%) were ceramic brackets. The statistical analysis revealed significant differences between the groups (p < 0.05).

Conclusions

Metal brackets demonstrated significantly higher failure rates than ceramic brackets for both 6- and 12-month observation periods (p < 0.05). The 6% difference between the brackets is clinically significant as it corresponds to one additional failure within 12 months.

Predicting the bracket bond failure rate in orthodontic patients: A retrospective cohort study

The aim of this study was to determine the risk factors associated with orthodontic bracket bond failure and to develop a prediction equation for orthodontic bracket bond failure rate using the risk factors. This was a retrospective cohort study conducted on a sample of 690 brackets in orthodontic patients aged 10 to 28 years old (mean age 17.97±5.11 years old) visiting a dental hospital. The effect of various parameters of orthodontic bond strength was assessed on bracket failure rate using survival analysis. Parametric (exponential) regression analysis was used to determine the risk factors associated with bracket failure and a prediction equation was formulated to predict the bracket failure rate. The overall mean survival time for the brackets was 3.04 (2.9-3.17) years. The univariate analysis showed a statistically significant (P<0.05) association of bracket material, site, overjet, overbite, incisor and molar classification and age. The multivariate analysis showed a significant interaction between site and side along with bracket material, jaw, overjet and overbite in the model. The risk of bracket failure on the right posterior region is 7.7 times that in the right anterior region when adjusted for all other variables in the model (HR: 7.7; 95% CI: 4.3-13.6). The model including bracket material, jaw, overjet, overbite and interaction between site and side can be used as a predictor of hazard rate for orthodontic bracket failure. Care should be taken in bonding brackets in the posterior region, as their debonding rate is higher as compared to anterior region.

Clinical performance of uncoated and precoated polymer mesh base ceramic brackets

Background

To evaluate the clinical performance of the two types of InVu ceramic brackets. The clinical performance of these brackets was measured by determining failure as well as survival rates and tie-wing fractures. Enamel surface evaluation following bracket and remnant removal was performed.

Subjects and methods

Forty non-extraction patients (31 females, 9 males) with a mean chronological age of 16 years 4 months composed this study. Bonding was performed with a split-mouth design using operator-coated and Readi-Base eXact InVu brackets. During the treatment period (45.89 ± 2.0 weeks), the failed brackets were recorded as well as the brackets with tie-wing fractures. Debracketing was undertaken with a ligature cutter (delamination technique) as recommended by the manufacturer. A modified remnant index (MRI) was used to visually evaluate the amount of remnants remaining on the tooth surface. Horizontal crack evaluation was carried out via transillumination.

Results

Operator-coated InVu brackets demonstrated a bond failure rate of 2.6%. This value was 6.8% for the Readi-Base eXact InVu brackets. Failure rates as well as survival rates presented a statistically significant difference (P = 0.006). A higher bond failure for the premolar teeth when compared to incisor teeth, as well as a higher bond failure in the lower arch when compared to the upper arch was found. These findings were statistically significant (P = 0.000 and P = 0.007, respectively). The effect of gender on bond failure rate (P = 0.508) and survival rate (P = 0.503) was not statistically significant. Both bracket types showed comparable results for tie-wing fractures (P = 0.174). A statistically significant difference was obtained for the MRI scores (P = 0.000). No horizontal enamel cracks were observed for both bracket types.

Conclusion

The operator-coated InVu brackets demonstrated a lower failure rate when compared to the Readi-Base eXact pre-applied adhesive InVu brackets. The debonding procedure was safe for both bracket types.

The association between patient's compliance and age with the bonding failure of orthodontic brackets: a cross-sectional study

Background

An efficient orthodontic treatment must aim the best occlusal result in the shortest possible time. One of the factors that can interfere in this goal is the bracket debonding during the treatment. This study aimed at assessing the different factors related to brackets failure, highlighting age and patient cooperation with treatment.

Methods

The sample comprised 199 orthodontic patients of both genders (103 women and 96 men); divided into two groups—adolescents (12 to 18 years old, 118 patients) and adults (19 to 59 years old, 81 patients). A questionnaire was applied regarding the motivation of patients to seek treatment and whether they had received information on appliance care; patients also filled out their level of cooperation with treatment in a visual analog scale (VAS). Additionally, other variables were assessed, such as the teeth with bracket debonding, the presence of deep overbite, and the use of bite plate. The Mann-Whitney test was used, and a 5% significance level was applied for analyses.

Results

It was observed that 20.1% of patients presented at least one tooth with bracket failure, and the lower arch was the most prevalent site (47.5%). Adolescents presented more debonding (25.4%) than adults (12.3%). Individuals with better VAS scores on cooperation sought treatment on their own (p = 0.042), were adults (p ≤ 0.001), and showed lower rate of failure of brackets (p ≤ 0.001). The factors related to malocclusion and treatment performed had no statistical significance.

Conclusion

Greater cooperation was expected from adult individuals who sought treatment on their own and presented low rate of bracket failure.

Incidence of orthodontic brackets detachment during orthodontic treatment: A systematic review

OBJECTIVES

To evaluate the incidence of orthodontic brackets detachment during orthodontic treatment.

METHODS

Using electronic databases; eligible studies up to January 2018 were retrieved, independently reviewed, and screened. The Coleman Methodology Scoring System (CMS) and Cochrane Collaboration's tool were used to assess quality and risk of bias in the included studies.

RESULTS

Of the seventeen studies included in the final synthesis, thirteen were categorized as randomized clinical trials (RCTs), one prospective cohort and retrospective survey each, whereas two studies could not be categorized. The number of patients in the selected studies ranged between 19 and 153; the mean age was between 10.5 to 38.7 years, and male to female ratio was 353:495. Almost all studies had a high risk of bias, and more than half of the studies had CMS score of 70 or above. The numbers of brackets examined in the studies ranged between 361 and 3336. The incidence of brackets detachment ranged from 0.6 to 28.3%.

CONCLUSIONS

The incidence of brackets detachment during orthodontic treatment is high.

Clinical long-term success of contemporary nano-filled resin composites in class I and II restorations cured by LED or halogen light

OBJECTIVES

The use of LED light-curing units (LED LCUs) for polymerising resin-based composite restorations has become widespread throughout dentistry. Unfortunately, there is a paucity of clinical longitudinal studies that evaluate the comparative efficacy of LED-based polymerisation in direct posterior composite restorations. The aim of the present study was to investigate the performance of class I and II resin composite restorations for two successful composite restorative materials cured with LED versus halogen LCUs.

METHODS

One hundred restorations were placed using the nano-filled composites Grandio® or Filtek™ Supremé. The following test groups were established: LED-Grandio® n = 23 (LG), LED-Filtek™ Supremé n = 21 (LS). As controls were used: Halogen-Grandio® n = 28 (HG), Halogen-Filtek™ Supremé n = 28 (HS). All restorations were evaluated according to the clinical criteria of the CPM index (C-criteria) at baseline and after 6, 12 and 36 months.

RESULTS

After 12 and 36 months, there were no significant differences between restorations polymerised with LED or halogen light. At the end of the study, 97% of the restorations showed sufficient results regardless of the employed LCU or composite. Globally, after 36 months, 56% of all restorations were assessed with code 0 (excellent) and 41% with code 1 (acceptable). In detail, excellent results (code 0) among the criteria surface quality; marginal integrity and marginal discoloration were assigned in 72, 70 and 69%.

CONCLUSIONS

For the current limitations in the clinical trial design, the results showed that LED-polymerisation is appropriate to ensure clinical success of direct posterior resin composite restorations in a range of 3 years.

CLINICAL SIGNIFICANCE

The choice of LCU has no significant influence on the clinical performance of posterior direct resin composite restorations within 3 years of wear.

Clinical effect of reducing curing times with high-intensity LED lights

OBJECTIVE

To evaluate the clinical performance of brackets cured with a high-intensity, light-emitting diode (LED) with a shorter curing time.

MATERIALS AND METHODS

Thirty-four patients and a total of 680 brackets were examined using a randomized split-mouth design. The maxillary right and mandibular left quadrants were cured for 6 seconds with a high-intensity LED light (3200 mW/cm(2)) and the maxillary left and mandibular right quadrants were cured for 20 seconds with a standard-intensity LED light (1200 mW/cm(2)). Alternating patients had the quadrants inverted for the curing protocol. The number and date of each first-time bracket failure was recorded from 199 to 585 days posttreatment.

RESULTS

The bracket failure rate was 1.18% for both curing methods. The proportion of bracket failure was not significantly different between curing methods (P  =  1.000), genders (P  =  1.000), jaws (P  =  .725), sides (P  =  .725), or quadrants (P  =  .547). Posterior teeth exhibited a greater proportion of failures (2.21%) relative to anterior teeth (0.49%), although the difference was not statistically significant (P  =  .065).

CONCLUSIONS

No difference was found in bond failure rates between the two curing methods. Both methods showed bond failure rates low enough to be considered clinically sufficient. The high-intensity LED light used with a shorter curing time may be considered an advantage due to the reduced chair time.

How and why of orthodontic bond failures: An in vivo study

Introduction:

The bonding of orthodontic brackets and their failure rates by both direct and in-direct procedures are well-documented in orthodontic literature. Over the years different adhesive materials and various indirect bonding transfer procedures have been compared and evaluated for bond failure rates. The aim of our study is to highlight the use of a simple, inexpensive and ease of manipulation of a single thermo-plastic transfer tray and the use the of a single light cure adhesive to evaluate the bond failure rates in clinical situations.

Materials and Methods:

A total of 30 patients were randomly divided into two groups (Group A and Group B). A split-mouth study design was used, for, both the groups so that they were distributed equally with-out bias. After initial prophylaxis, both the procedures were done as per manufactures instructions. All patients were initially motivated and reviewed for bond failures rates for 6 months.

Results:

Bond failure rates were assessed for over-all direct and indirect procedures, anterior and posterior arches, and for individual tooth. Z-test was used for statistically analyzing, the normal distribution of the sample in a spilt mouth study. The results of the two groups were compared and P value was calculated using Z-proportion test to assess the significance of the bond failure.

Conclusion:

Over-all bond failure was more for direct bonding. Anterior bracket failure was more in-direct bonding than indirect procedure, which showed more posterior bracket failures. In individual tooth bond failure, mandibular incisor, and premolar brackets showed more failure, followed by maxillary premolars and canines.

Effects of tooth bleaching on shear bond strength of brackets rebonded with a self-etching adhesive system

The purpose of this study was to ascertain the effects of tooth bleaching on the shear bond strength of orthodontic brackets rebonded with a self-etching adhesive system. A total of 39 premolars were collected and divided into three equal groups: in group 1 bracket bonding was performed without bleaching treatment; specimens in group 2 were bonded immediately after bleaching; and group 3 teeth were bleached, then immersed in artificial saliva and left for 7 days before bonding. The shear bond strength was measured, with the bonding/debonding procedures repeated once after the first debonding, and the bracket/adhesive failure modes were evaluated by the adhesive remnant index after each debonding. Excepting the mean shear bond strength for group 2 after the first debonding, the overall mean values reached the minimum clinical requirement of 6 MPa. The mean values at the first and second debondings were significantly higher in groups 1 and 3 than in group 2. Between groups 1 and 3, significant differences were noted at the first debonding, but not at the second debonding. Group 2 showed significant differences in mean shear bond strength between the first and second debondings. Bond failure at the enamel-adhesive interface occurred more frequently in group 2 than in groups 1 or 3 after the first debonding. The bracket-rebonding procedure can recover the reduced shear bond strength caused by immediate bonding after bleaching to a clinically acceptable level, but not to the prebleaching level.