The effects of sandblasting on the bond strength of molar attachments--an in vitro study

Evaluation of failure rate of molar tubes with a modified bonding technique: a randomized clinical trial

BACKGROUND

During orthodontic therapy, bond failure of molar tubes may delay treatment. With the high failure rate of molar tubes, alternative bonding techniques were tested to improve bond strength.

OBJECTIVES

To compare the failure rates of molar tubes bonded with conventional and alternative bonding techniques by adding a layer of compomer adhesive at the molar/tube interface.

TRIAL DESIGN

Single-centre, single-blinded, split-mouth, randomized clinical trial.

METHODS

Patients aged 12 years or older, who required fixed appliance orthodontic treatment without extraction and with no occlusal interference were eligible to participate. They were allocated randomly using a simple non-stratified split-mouth design with a 1:1 allocation ratio. Blinding was only possible for the patients and data analysts. Molar tubes bonded with the modified bonding technique had an additional layer of compomer at the occlusal molar/tube interface. The patients were followed-up for nine months. Outcome measures included the survival time of molar tubes and the number of molar tubes debonded. The bond failure of molar tubes was analyzed using Kaplan-Meier and Cox regression analysis (P < 0.05).

RESULTS

Thirty patients were recruited, randomized, and analyzed (mean age 20.33 years). The failure rate of molar tubes bonded with the modified bonding technique was 4.2 per cent and that of molar tubes bonded with the conventional bonding technique was 6.7 per cent. This difference was not statistically significant (P > 0.05). The dental arch and molar type were found to be as significant predictors for molar tube failure rate. No harm was detected during treatment.

LIMITATIONS

The effect of compomer to reduce enamel demineralization was not tested.

CONCLUSIONS AND IMPLICATIONS

The modified bonding technique did not significantly reduce the failure rate of molar tubes. The molar tubes bonded on the upper arch and second molars are more susceptible to debond.

REGISTRATION

The trial was registered with ClinicalTrials.gov on 21 May 2022 (Registration number: NCT05391386).

FUNDING

This research did not receive any funding.

The effect of prior sandblasting of the wire on the shear bond strength of two different types of lingual retainers

PURPOSE

The aim of this study was to evaluate the effect of total surface sandblasting on the shear bond strength of two different retainer wires. The null hypothesis was that there is no difference in the bond strength of the two types of lingual retainer wires when they are sandblasted.

MATERIALS AND METHODS

One hundred and sixty human premolar teeth were equally divided into four groups (n=40). A pair of teeth was embedded in self-curing acrylic resin and polished. Retainer wires were applied on the etched and rinsed surfaces of the teeth. Four retainers were used: group 1: braided retainer (0.010×0.028″, Ortho Technology); group 2: sandblasted braided retainer (0.010×0.028″, Ortho Technology); group 3: coaxial retainer (0.0215″ Coaxial, 3M) and group 4: sandblasted coaxial retainer (0.0215″ Coaxial, 3M). The specimens were tested using a universal test machine in shear mode with a crosshead speed of one mm/min.

RESULTS

One-way analysis of variance (Anova) was used to determine the significant differences among the groups. There was no significant difference (P=0.117) among the groups according to this test.

CONCLUSIONS

The null hypothesis was accepted. There was no statistically significant difference among the shear bond strength values of the four groups.

Defining the location of the dental midline is critical for oral esthetics in camouflage orthodontic treatment of facial asymmetry

When considering camouflage orthodontic treatment of a malocclusion associated with significant facial asymmetry, it is important to define the location of the dental midline. The patient, a 19-year-old Japanese woman, had an anterior open bite and a dental midline discrepancy associated with facial asymmetry. A nonsurgical treatment plan was considered. The main treatment objective was to correct the anterior open bite and the dental midlines in both arches. The dental midline discrepancy was eliminated, and proper overjet and overbite were achieved. Although the facial asymmetry remained, oral esthetics dramatically improved and a favorable occlusion was obtained. The results suggest that appropriately defining the location of the dental midline is critical for successful camouflage treatment of facial asymmetry.

The relationship between base dimensions, force to failure, and shear bond strengths of bondable molar tubes

OBJECTIVES

To compare forces versus failure and shear bond strengths, and to explore their association with the base dimensions of four currently available bondable molar tubes.

MATERIALS AND METHODS

Tubes were bonded to hydroxyapatite discs using a conventional light-cured adhesive and were tested to shear failure with the Instron Universal testing machine. Results were analyzed using the Kruskal-Wallis test and regression and survival analyses.

RESULTS

No statistical difference was observed between the four groups globally in terms of force to failure (P  =  .059) and bond strength (P  =  .179). However, regression analysis showed that each 1 mm(2) increase in base surface area required an additional force of 3.11 N to debond the tube. Survival analysis showed that the tube with the greatest base dimensions had the best survival with increasing force to failure.

CONCLUSIONS

Although a relationship was demonstrated between force to failure and base surface area, it was not a simple one. No statistically significant relationship was found between bond strength and base surface area.

Estudo in vitro da resistência ao cisalhamento da colagem direta de tubos ortodônticos em molares

INTRODUÇÃO: apesar da colagem direta despender menor tempo clínico, com maior preservação da integridade gengival, ainda hoje se observa uma alta incidência de bandagem dos molares. Portanto, torna-se interessante a idealização de recursos para o aumento da eficiência desse procedimento para dentes submetidos a maiores impactos mastigatórios, como, por exemplo, os molares. OBJETIVO: esse estudo teve o propósito de avaliar se a resistência à adesão com a aplicação de uma camada de resina adicional na região oclusal da interface tubo/dente aumenta a qualidade do procedimento de colagem direta de tubos em molares. MÉTODOS: selecionou-se uma amostra composta por 40 terceiros molares inferiores, que foram aleatoriamente divididos em 2 grupos: Grupo 1 - colagem direta convencional, seguida pela aplicação de uma camada de resina na oclusal da interface tubo/dente; e Grupo 2 - colagem direta convencional. O teste de resistência ao cisalhamento foi realizado 24 horas após a colagem, utilizando-se uma máquina de ensaio universal, operando a uma velocidade de 0,5mm/min. Os resultados foram analisados por meio do teste t independente. RESULTADOS: os valores médios obtidos nos testes de cisalhamento foram: 17,08MPa para o Grupo 1 e 12,60MPa para o Grupo 2. O Grupo 1 apresentou uma resistência ao cisalhamento estatisticamente significativa mais alta do que o Grupo 2. CONCLUSÃO: a aplicação de uma camada adicional de resina na oclusal da interface tubo/dente aumenta a qualidade da adesão do procedimento de colagem direta de tubos ortodônticos em molares.

In vitro evaluation of an alternative method to bond molar tubes

Despite the advances in bonding materials, many clinicians today still prefer to place bands on molar teeth. Molar bonding procedures need improvement to be widely accepted clinically.

Effect of sandblasting on the retention of orthodontic brackets: a controlled clinical trial

OBJECTIVE

To study the effect of chairside sandblasting of the bases upon the retention of mesh backed orthodontic brackets.

DESIGN

Prospective controlled clinical trial.

METHODS

Brackets were bonded to 60 successive patients who were treated at an orthodontic practice in Amman, Jordan. Using a crossover system of allocation, quadrants were bonded using either sandblasted or non-sandblasted brackets respectively. Rely-A-Bond adhesive was used throughout. Bond failures were monitored over one year.

RESULTS

1112 brackets were assessed. The overall failure rate was 4.0% and the failure rates for non-sandblasted and sandblasted brackets were 4.7 and 3.4% respectively. The odds ratio for at least one bracket failure within the control quadrant compared with the experimental quadrant was 0.50 (95% CI 0.185 to 1.238), which was not statistically significant.

CONCLUSION

Sandblasting did not significantly improve the retention of mesh based orthodontic brackets in this study.

Bonded versus banded first molar attachments: a randomized controlled clinical trial

OBJECTIVE

To compare the clinical failure rates of bonded first molar tubes with those of cemented bands during fixed appliance therapy.

DESIGN

Prospective randomized controlled clinical trial.

SETTING

Two UK hospital orthodontic clinics, February 2001-December 2004.

PARTICIPANTS

Hospital waiting list patients needing fixed appliances (n = 110).

METHOD

Patients were randomly allocated to two groups. Experimental group patients (n = 55) received single first molar tubes (n = 181) bonded with a no-mix chemically cured composite (Rely-A-Bond) after a 30-second etch. Control group patients (n = 55) were treated with bands (n = 186) cemented with Intact glass ionomer cement (GIC). First-time failures were recorded together with the time of failure. All patients were followed to the end or discontinuation of treatment.

RESULTS

First-time failures: bands = 18.8%; bonds = 33.7 %. Bonded tubes were more likely to fail [RR 2.4; 95% CI (1.4, 4.1)] compared with bands. Experimental group patients also had more bracket failures (P = 0.009), when analysed at patient level.

CONCLUSION

First molar tubes bonded with Rely-A-Bond composite showed a significantly higher first-time failure rate than bands cemented with Intact GIC.