Are units of analysis properly considered in orthodontic meta-analyses?

BACKGROUND

Assessment of unit of analysis (UoA) in meta-analysis with cluster, split-mouth, repeated measures designs, and multiple intervention groups is a fundamental step in the analysis. The objective of this study was to evaluate the UoAs in orthodontic meta-analysis and determine the error of the analysis.

METHODS

An electronic search was conducted in the Cochrane Library and PubMed to identify orthodontic systematic reviews (SRs) with meta-analyses published in Cochrane and in the highest impact orthodontic journals between 1 January 2013 and 31 December 2022. SRs with meta-analysis assessing at least one of the following UoAs; cluster trials, crossover trials, multiple observations, or multiple intervention groups were included. Screening and data extraction were undertaken by two investigators independently. Descriptive statistics for the study characteristics were provided. The associations between avoiding the unit analysis error (yes, no) and the study characteristics were examined using Fisher's exact test and chi-square test. Logistic regression was undertaken for the significant predictors.

RESULTS

Eighty SRs were deemed eligible for inclusion. Only 30 per cent of the included SRs avoided UoA errors. Compared to the split-mouth design, repeated measures designs had higher odds of avoiding UoA error (odds ratio: 9.6, 95% confidence interval: 2.8-32.3, P < 0.001). In contrast, fewer odds of avoiding the UoA error were found in the cluster design (OR: 0.2, 95% CI: 0.4-1.3, P = 0.09). Though multiple intervention groups have higher odds of avoiding UoA error than split-mouth studies, this was not statistically significant (OR: 2.1, 95% CI: 0.5-8, P = 0.28). None of the SRs characteristics have influenced the appropriate handling of the unit analysis except the type of the journal; the odds of avoiding the UoA error were higher in Cochrane reviews than the non-Cochrane reviews (OR: 3.3, 95% CI: 1.2-8.7, P = 0.02), and the number of authors (P < 0.05).

CONCLUSIONS

UoA errors are common in orthodontic meta-analyses and were only partially avoided in split-mouth design, repeated measures design, and multiple intervention groups.

Is clustering accounted for in studies published in periodontology and oral implantology specialty journals?

BACKGROUND

Clustering effects can be encountered in periodontology and implant dentistry research. The aim of this study was to identify studies with clustering effects published in periodontology and oral implantology specialty journals and to assess the frequency by which clustered designs are correctly accounted for in the statistical analysis.

METHODS

Ten periodontology and oral implantology journals were searched to identify studies with clustering effects published between January 1, 2019 and July 31, 2021. Descriptive statistics and frequency distributions were calculated. Associations between the correct statistical handling of clustering effects and study characteristics were explored.

RESULTS

A total of 695 studies were included of which 45.0% correctly accounted for clustering effects in the statistical analysis. Certain journals (p < 0.01) and animal studies (p < 0.01) had lower odds of correctly accounting for clustering effects in the statistical analysis, whereas per unit increase in impact factor (p < 0.001), involvement of statistician (p < 0.001) and when the study design included either repeated measures only (p < 0.01) or both clustering and repeated measures (p < 0.001) had higher odds. The most commonly used tests were the mixed models or generalized estimating equations (64.2%).

CONCLUSIONS

Greater awareness of the importance of accounting for clustering effects is required to prevent incorrect inferences being drawn. Incorrect inferences are related to lack of data independence and the artificial inflation of the sample size which can result in statistically significant results which are not genuine. This issue can be further exaggerated in combination with publication bias.

Accounting for clustering is still not routinely undertaken in orthodontic studies

BACKGROUND

The aim of this study was to identify studies with clustering effects published in orthodontic journals and to assess the frequency by which clustered designs are correctly accounted for in the statistical analysis. Factors associated with appropriate management of clustering effects during the statistical analysis were explored.

MATERIALS AND METHOD

A search of three leading orthodontic journals was undertaken to identify studies with clustering effects published between 1 January 2019 and 31 December 2021. Descriptive statistics and frequency distributions were calculated. Associations between the correct statistical handling of clustering effects and study characteristics were explored via univariable and multivariable analyses.

RESULTS

Three hundred and sixty-two studies were considered to have clustering effects. Only 22.4 per cent of studies correctly accounted for clustering effects in the statistical analysis with no improvement compared to a previous study in 2012 using the same journals. An association between the use of the correct analysis to account for clustering and the following study characteristics was detected: involvement of statistician, study type, significance of the results, and accounting for clustering in the sample size calculations. In the univariable analysis, interventional studies, non-significant results, and the involvement of a statistician were associated with higher odds of the use of the correct analysis. Of the studies correctly accounting for clustering, the most used tests were repeated measures ANOVA (43.3 per cent) and mixed models (40.7 per cent).

CONCLUSIONS

Compared to previous research, there appears to be no improvement in accounting for clustering effects in studies published in orthodontic journals. To prevent incorrect inferences being drawn, clustering effects need to be recognised and accounted for in orthodontic studies. Recommendations to improve the accounting of clustering effects, at both the study level and during the statistical analysis are suggested.

Are longitudinal randomised controlled oral health trials properly analysed? A meta-epidemiological study

INTRODUCTION

Longitudinal designs with multiple outcome measurements are commonly encountered in oral health randomised controlled trials (RCTs). The aim of this meta epidemiological study was to assess whether optimal statistical analysis approaches have been used in longitudinal oral health RCTs.

DATA SOURCES

PubMed search was undertaken in September 2021 for longitudinal oral health RCTs with at least 3 repeated outcome measurements which have been published between 2016- 2020 in the highest impact general and specialty dental journals.

STUDY SELECTION

Study selection and data extraction were accomplished independently and in duplicate. The statistical methods undertaken in the selected articles were tabulated, and the association between study characteristics and use of optimal analyses were assessed using X² or Fisher's exact test and logistic regression.

RESULTS

Five hundred and five oral health RCTs were deemed eligible for inclusion. Of these, only 28.3% RCTs used optimal statistical analyses for a longitudinal trial design. For the trials with an optimal statistical approach, the most frequent test used was repeated measures analysis of variance (RM-ANOVA) followed by mixed effect models (MEM). The use of optimal statistical tests was predicated by the involvement of a statistician (OR: 2, 95% CI:1.27 - 3.18, p<0.01), the journal impact factor (OR:1.19, 95% CI;1.1 - 1.29), continent of first author (likelihood ratio test p=0.01), number of the authors (OR:1.22, 95% CI;1.12-1.3, p<0.001), protocol registration (OR: 1.48, 95%CI; 1 to 2.2, p=0.05), funding(OR:2.4, 95%CI; 1.6 - 3.7, p<0.001), and dental specialty (likelihood ratio test p<0.001).

CONCLUSIONS

Most longitudinal oral health RCTs did not use optimal statistical analyses. Greater awareness of optimal analyses used to assess longitudinal data reported in oral health trials is required to circumvent the reporting of suboptimal inferences, selective reporting and research waste.

CLINICAL SIGNIFICANCE

Further progress is required to avoid suboptimal statistical analyses and fully utilise the benefits of the repeated measurements over time in oral health RCTs.

Do longitudinal orthodontic trials use appropriate statistical analyses? A meta-epidemiological study

BACKGROUND

In orthodontic trials, longitudinal designs with multiple outcome measurements over time are common. The aim of this epidemiological study was to examine whether optimal statistical analysis approaches have been used in longitudinal orthodontic trials.

METHODS

Pubmed was searched in August 2021 for longitudinal orthodontic trials with at least three time points of outcome assessment published in the 2017-20 period. Study selection and data extraction were done independently and in duplicate. The analysis approaches undertaken were tabulated and associations between study characteristics and the use of optimal analysis or not were assessed using Fisher's exact test and logistic regression.

RESULTS

One hundred forty-seven out of 563 unique records were deemed eligible for inclusion. Only 26.50% of these trials used an optimal statistical analysis for longitudinal data where the data structure is accounted for. None of the study characteristics except the statistical significance of the results were associated with the appropriateness of the statistical analysis. The odds of significant results in studies with suboptimal analyses were higher than that in studies with optimal longitudinal analyses (odds ratio: 3.48, 95% confidence interval: 1.62, 7.46, P = 0.001). For the studies with optimal analysis, the most frequent test was repeated-measure analysis of variance (RM-ANOVA). The reporting of the statistical analysis section was suboptimal in the majority of the trials.

CONCLUSION

Most longitudinal orthodontic trials are not analysed using optimal statistical approaches. Inferences and interpretation of their results are likely to be compromised.

The reporting quality of split-mouth trials in orthodontics according to CONSORT guidelines: 2015-19

OBJECTIVES

To assess the reporting quality of split-mouth trials (SMTs) in orthodontic journals, and to identify factors associated with better reporting.

MATERIALS AND METHODS

Seven leading orthodontic journals were hand searched for SMTs published during 2015-19. The CONSORT 2010 guideline and CONSORT for within-person trial (WPT) extension were used to assess the trial reporting quality (TRQ) and WPT-specific reporting quality (WRQ) of included SMTs, respectively. A binary score (0 or 1) was given to each item of the guidelines, and total scores were calculated for TRQ (score range, 0-32) and WRQ (score range, 0-15). Univariable and multivariable linear regression analyses were performed to identify factors associated with TRQ and WRQ.

RESULTS

A total of 42 SMTs were included. The mean overall scores for TRQ and WRQ were 16.8 [standard deviation (SD) 7.1] and 5.6 (SD 2.3), respectively. Only 11 SMTs (26.2%) presented the rationale for using a split-mouth design. Key methodological items including random sequence generation (22/42, 52.4%), allocation concealment (9/42, 21.4%), and blinding (20/42, 47.6%) were poorly reported. Only six SMTs (14.3%) used a paired method for sample size calculation, and half (21/42, 50.0%) considered the dependent nature of data in statistical analysis. In multivariable analyses, higher TRQ and WRQ were both significantly associated with journal, reported use of CONSORT and funding status.

CONCLUSIONS

The reporting quality of SMTs in orthodontics has much room for improvement. Joint efforts from relevant stakeholders are needed to improve the reporting quality of SMTs and reduce relevant avoidable research waste.

Dental Research Waste in Design, Analysis, and Reporting: A Scoping Review

Research waste is highly prevalent across biomedical investigations. We aimed to assess the evidence on the extent of research waste in dental research. We performed a scoping review of empirical evaluations of dental studies assessing the prevalence and impact of limitations in design, conduct, analysis, and reporting of research. PubMed was searched using specific terms to retrieve studies dealing with design, conduct, analysis, and reporting of studies in dentistry, with no year or language restrictions. Of the 1,807 publications identified from the search and from manual searches, 71 were included in this review. The topic and article selection was based on the expert opinion of the authors. The existing evidence suggests that, although there are improvements over time, substantial deficiencies in all areas (design, conduct, analysis, reporting) were prevalent in dental research publications. Waste in research is a multifaceted problem without a simple solution. However, an appreciation of optimal research design and execution is a prerequisite and should be underpinned by policies that include appropriate training in research methods and properly aligned incentives.

Outcome of periodontal–orthodontic treatment in subjects with periodontal disease. Part II: a CBCT study of alveolar bone level changes

Aim

To examine alveolar bone level (ABL) changes before (T1) and after (T2) orthodontic treatment (OT) in subjects with periodontal disease.

Methods

The study included 50 subjects with periodontal disease. All patients received subgingival debridement following baseline examination. Control group patients received final periodontal treatment before the start of OT. For the test group patients final periodontal treatment was performed simultaneous to OT. OT was performed with a straight-wire appliance. Micro-implants or temporary crowns on implants were used for posterior anchorage when needed. ABL measurements of 3821 tooth surfaces were performed on cone beam computed tomography images.

Results

No difference was observed between mean ABL at T1 and T2. ABL remained unchanged on 69 per cent of surfaces. A mean of 15.6 (SD 7.4) per cent of surfaces experienced ABL gain, and a mean of 15.1 (SD 7.5) per cent was found with ABL loss. Small significant median ABL difference was observed on mesial and distal surfaces (P < 0.001). A significant difference was found between median ABL changes on mesial/distal in comparison to buccal/lingual surfaces (P < 0.01). Significantly more buccal (17.9 %) and lingual (18.5 %) surfaces experienced ABL loss when compared with mesial (11.3 %) and distal (12.0 %) surfaces (P < 0.001). Significant difference was found in the median ABL change of intruded (0.5 (IQR 0.94) mm) and non-intruded (−0.4 (IQR 1.07) mm) maxillary incisors (P = 0.04). Significant median ABL gain was found on the lingual surface of maxillary incisors, which were retroclined more than 8.6 degree and intruded more than 1.6 mm.

Conclusions

ABL changes after periodontal–orthodontic treatment in patients with periodontal disease were small. ABL gain was more observed on mesial and distal surfaces and ABL loss on buccal and lingual surfaces. Larger orthodontic movements of maxillary incisors influenced ABL gain.

Registered trials report less beneficial treatment effects than unregistered ones: a meta-epidemiological study in orthodontics

OBJECTIVES

Clinical trial registration is widely recommended because it allows tracking of trials that helps ensure full and unbiased reporting of their results. The aim of the present overview was to provide empirical evidence on bias associated with trial registration via a meta-epidemiological approach.

STUDY DESIGN AND SETTINGS

Six databases were searched in September 2017 for randomized clinical trials and systematic reviews thereof assessing the effects of orthodontic clinical interventions. After duplicate study selection and data extraction, statistical analysis included a two-step meta-epidemiological approach within- and across-included meta-analyses with a Paule-Mandel random-effects model to calculate differences in standardized mean differences (ΔSMD) between registered and unregistered trials and their 95% confidence intervals (CI), followed by subgroup and sensitivity analyses.

RESULTS

A total of 16 meta-analyses with 83 trials and 4,988 patients collectively were finally included, which indicated that registered trials reported less beneficial treatment effects than unregistered trials (ΔSMD = -0.36; 95% CI = -0.60, -0.12). Although some small-study effects were identified, sensitivity analyses according to precision and risk of bias indicated robustness.

CONCLUSION

Signs of bias from lack of trial protocol registration were found with nonregistered trials reporting more beneficial intervention effects than registered ones. Caution is warranted by the interpretation of nonregistered randomized trials or systematic reviews thereof.

Interventions for orthodontically induced white spot lesions: a systematic review and meta-analysis

Background

Although orthodontic white spot lesions (WSLs) are one of the most often and most evident adverse effects of comprehensive fixed appliance treatment, the efficacy of interventions for WSLs has not yet been adequately assessed in an evidence-based manner.

Objective

Aim of this systematic review was to assess the therapeutic and adverse effects of interventions to treat post-orthodontic WSLs from randomized trials in human patients.

Search methods

An unrestricted electronic search of eight databases from inception to May 2016.

Selection criteria

Randomized controlled trials assessing any interventions for post-orthodontic WSLs on human patients.

Data collection and analysis

After duplicate study selection, data extraction, and risk of bias assessment according to the Cochrane guidelines, random-effects meta-analyses of mean differences (MDs), standardized mean differences (SMDs), and odds ratios (ORs), including their 95% confidence intervals (CIs) were performed, followed by subgroup and sensitivity analyses.

Results

A total of 20 unique studies and a total of 942 (42 per cent male and 58% per cent female) patients were included, with an average age of 16.2 years and a mean number of 8.2 WSLs (range 2.2 to 45.4) per patient. These were allocated to adjunct treatment with casein phosphopeptide-stabilized amorphous calcium phosphate creams, external tooth bleaching, low- or high-concentration fluoride films, gels, mouthrinses or varnishes, resin infiltration, miswak chewing sticks, bioactive glass toothpastse, or to no adjunct treatment (i.e. conventional oral hygiene). The monthly use of fluoride varnish was the best supplement to improve WSLs in terms of lesion area (1 trial; MD = -0.80 mm2; 95% CI = -1.10, -0.50 mm2; P < 0.05; high quality) and enamel fluorescence (3 trials; SMD = -0.92; 95% CI = -1.32, -0.52; P < 0.05; high quality), followed by the use of fluoride film. WSL treatment did not provide a considerable improvement in their clinical evaluation (3 trials; OR = 0.97; 95% CI = 0.60, 1.56; P > 0.05; moderate quality), with imprecision due to small sample size being the main limitation of existing evidence.

Conclusions

Based on the existing trials, interventions for post-orthodontic WSLs, mainly fluoride varnish, seem to be effective, but further research is needed to elucidate their clinical relevance.

Registration

PROSPERO (CRD42016037538).

The Quality of the Evidence According to GRADE Is Predominantly Low or Very Low in Oral Health Systematic Reviews

Objectives

The main objective was to assess the credibility of the evidence using Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) in oral health systematic reviews on the Cochrane Database of Systematic Reviews (CDSR) and elsewhere.

Study Design and Setting

Systematic Reviews or meta-analyses (January 2008-December 2013) from 14 high impact general dental and specialty dental journals and the Cochrane Database of Systematic Reviews were screened for meta-analyses. Data was collected at the systematic review, meta-analysis and trial level. Two reviewers applied and agreed on the GRADE rating for the selected meta-analyses.

Results

From the 510 systematic reviews initially identified 91 reviews (41 Cochrane and 50 non-Cochrane) were eligible for inclusion. The quality of evidence was high in 2% and moderate in 18% of the included meta-analyses with no difference between Cochrane and non-Cochrane reviews, journal impact factor or year of publication. The most common domains prompting downgrading of the evidence were study limitations (risk of bias) and imprecision (risk of play of chance).

Conclusion

The quality of the evidence in oral health assessed using GRADE is predominantly low or very low suggesting a pressing need for more randomised clinical trials and other studies of higher quality in order to inform clinical decisions thereby reducing the risk of instituting potentially ineffective and/or harmful therapies.

The CONSORT Statement: Application within and adaptations for orthodontic trials

High-quality randomized controlled trials (RCTs) are an integral part of evidence-based medicine. RCTs are the bricks and mortar of high-quality systematic reviews, which are important determinants of health care policy and clinical practice. For published research to be used most effectively, investigators and authors should follow the guidelines for accurate and transparent reporting of RCTs. The consolidated standards of reporting trials (CONSORT) statement and its extensions are among the most widely used reporting guidelines in biomedical research. CONSORT was adopted by the American Journal of Orthodontics and Dentofacial Orthopedics in 2004. Since 2011, this Journal has been actively implementing compliance with the CONSORT reporting guidelines. The objective of this explanatory article is to highlight the relevance and implications of the various CONSORT items to help authors to achieve CONSORT compliance in their research submissions of RCTs to this and other orthodontic journals.

Do we need primer for orthodontic bonding? A randomized controlled trial

OBJECTIVE

To evaluate the clinical performance of APC™II Victory Series™ (3M Unitek) brackets in direct orthodontic bonding with and without the use of primer.

DESIGN

A single-operator, two-centre prospective, non-inferiority randomized controlled clinical trial.

SETTING

The Orthodontic departments at the Leeds Dental Institute and St Luke's Hospital, Bradford, UK.

ETHICAL APPROVAL

Ethical approval was granted by Leeds (East) Research Ethics Committee on 18th of December 2009 (Reference 09/H1306/102).

PROTOCOL

The protocol was not published prior to trial commencement.

SUBJECTS AND METHODS

Ninety-two patients requiring orthodontic treatment with fixed appliances were randomly allocated to the control (bonded with primer) or test groups (bonded without primer). Patients were randomly allocated to either the control or experimental group. This was performed by preparing opaque numbered sealed envelopes in advance using a random numbers table generated by a computer by an independent third party . Once the envelopes were opened, blinding of the operator and the patient was no longer possible due to the nature of the intervention. Patients were approached for inclusion in the trial if they qualified for NHS orthodontic treatment requiring fixed appliances and had no previous orthodontic treatment.

MAIN OUTCOME MEASURES

Number of bracket failures, time to bond-up appliances, and the adhesive remnant index (ARI) when bracket failure occurred, over a 12-month period

RESULTS

Failure rate with primer was 11.1 per cent and without primer was 15.8 per cent. Bonding without primer was shown statistically to be non-inferior to bonding with primer odds ratio 0.95-2.25 (P = 0.08). Mean difference in bond-up time per bracket was 0.068 minutes (4 seconds), which was not statistically significant (P = 0.402). There was a statistically significant difference in the Adhesive Remnant Index - ARI 0 with primer 49.4 per cent, no primer 76.5 per cent, (P < 0.0001).

LIMITATIONS

As the study was only performed by one operator, the results can therefore only be truly be applied to their practice. Also this study was powered to ascertain if there was no difference between the 2 groups up to 5%, however orthodontists may consider a change in the bracket failure rate of 2% to be clinically significant.

CONCLUSION

When bonding with APC™II Victory Series™ brackets without primer was shown statistically to be non-inferior to bonding with primer (P =0.08). There was no significant difference in bond-up times. Bond failure was more likely to happen at the composite-enamel interface when bonded without a primer.

CONFLICT OF INTEREST

No conflict of interest for all authors.

FUNDING

No funding sources were used.

REGISTRATION

Study was not registered on external databases.

Methodological characteristics and treatment effect sizes in oral health randomised controlled trials: Is there a relationship? Protocol for a meta-epidemiological study

INTRODUCTION

It is fundamental that randomised controlled trials (RCTs) are properly conducted in order to reach well-supported conclusions. However, there is emerging evidence that RCTs are subject to biases which can overestimate or underestimate the true treatment effect, due to flaws in the study design characteristics of such trials. The extent to which this holds true in oral health RCTs, which have some unique design characteristics compared to RCTs in other health fields, is unclear. As such, we aim to examine the empirical evidence quantifying the extent of bias associated with methodological and non-methodological characteristics in oral health RCTs.

METHODS AND ANALYSIS

We plan to perform a meta-epidemiological study, where a sample size of 60 meta-analyses (MAs) including approximately 600 RCTs will be selected. The MAs will be randomly obtained from the Oral Health Database of Systematic Reviews using a random number table; and will be considered for inclusion if they include a minimum of five RCTs, and examine a therapeutic intervention related to one of the recognised dental specialties. RCTs identified in selected MAs will be subsequently included if their study design includes a comparison between an intervention group and a placebo group or another intervention group. Data will be extracted from selected trials included in MAs based on a number of methodological and non-methodological characteristics. Moreover, the risk of bias will be assessed using the Cochrane Risk of Bias tool. Effect size estimates and measures of variability for the main outcome will be extracted from each RCT included in selected MAs, and a two-level analysis will be conducted using a meta-meta-analytic approach with a random effects model to allow for intra-MA and inter-MA heterogeneity.

ETHICS AND DISSEMINATION

The intended audiences of the findings will include dental clinicians, oral health researchers, policymakers and graduate students. The aforementioned will be introduced to the findings through workshops, seminars, round table discussions and targeted individual meetings. Other opportunities for knowledge transfer will be pursued such as key dental conferences. Finally, the results will be published as a scientific report in a dental peer-reviewed journal.

Cluster randomized clinical trials in orthodontics: design, analysis and reporting issues

Cluster randomized trials (CRTs) use as the unit of randomization clusters, which are usually defined as a collection of individuals sharing some common characteristics. Common examples of clusters include entire dental practices, hospitals, schools, school classes, villages, and towns. Additionally, several measurements (repeated measurements) taken on the same individual at different time points are also considered to be clusters. In dentistry, CRTs are applicable as patients may be treated as clusters containing several individual teeth. CRTs require certain methodological procedures during sample calculation, randomization, data analysis, and reporting, which are often ignored in dental research publications. In general, due to similarity of the observations within clusters, each individual within a cluster provides less information compared with an individual in a non-clustered trial. Therefore, clustered designs require larger sample sizes compared with non-clustered randomized designs, and special statistical analyses that account for the fact that observations within clusters are correlated. It is the purpose of this article to highlight with relevant examples the important methodological characteristics of cluster randomized designs as they may be applied in orthodontics and to explain the problems that may arise if clustered observations are erroneously treated and analysed as independent (non-clustered).

Twelve-month bracket failure rate with amorphous calcium phosphate bonding system

The aim of the study was to compare the survival rate of orthodontic brackets over a 12-month period using amorphous calcium phosphate (ACP) bonding system with a conventional adhesive (CA). In 30 patients with a mean age of 15 years 7 months, one operator bonded 138 brackets with a split-mouth design, using a resin-based CA and ACP-containing adhesive. The survival rate of the brackets was estimated by Kaplan-Meier analysis. Bracket survival distributions with respect to bonding procedure, dental arch, type of tooth (incisor, canine, and premolar), and patients' gender were compared using the log-rank test. The bond failure interface was determined using the Adhesive Remnant Index (ARI). The bond failure rates of the CA and ACP-containing adhesive were 2.67 and 3.8 per cent, respectively. There was no significant difference between the failure rates of ACP and CA-bonded systems (P > 0.05). Survival rates did not show significant differences between the upper and lower dental arches (P > 0.05). Lower survival rates were found for canine and premolar teeth than incisors (P < 0.05). Bond failure rates were higher for males than females (P < 0.05). There was a significant difference for ARI scores between the adhesive materials (P = 0.028); more of the ACP-based adhesive was left on the tooth at debond. ACP-containing adhesive can be effectively used to bond orthodontic brackets and can serve as a practicable alternative to the conventional bonding adhesives.