Introduction

The high worldwide prevalence of malocclusions has generated a considerable utilization of fixed orthodontic appliances. This led to an evaluation of bonding and debonding processes to assess not only benefits, but also risk of enamel integrity [1-3]. Debonding of brackets can cause damage to enamel surface, and discarding the remaining adhesive can result in up to 55.6 µm of tissue removal. In fact, tooth enamel cannot regenerate, so any injury or loss of the substance is permanent [3, 4].

Although the objective of adhesive bonding between orthodontic appliances and tooth enamel is to achieve an inseparable bond for the duration of orthodontic treatment, debonding of brackets is an inevitable and necessary final step [5]. Regardless of the instruments, equipment, and technique used, the objective of this final step is to achieve complete removal of adhesive material from the tooth surface to restore enamel’s initial characteristics [4, 6].

There are many factors influencing bracket debonding, of which, the most important are type of bracket and adhesive used, instrument used for bracket removal, and technique for resin discarding [7]. For example, metal brackets are the most widely used fixed appliances in modern orthodontics, but ceramic brackets are increasingly applied due to aesthetics [8, 9]. Although ceramic brackets are more fragile than metal brackets in terms of fracture possibility, their bonding to enamel requires greater adhesive strength [6]. This makes debonding ceramic brackets a challenge if integrity of enamel is to be preserved, considering that majority of American orthodontists in a study reported using pliers for their removal [8].

Once the brackets are removed, discarding of adhesive material and how it is done is another point to consider in possible loss of enamel [4]. The literature is extensive regarding methods available for removing these remains, which include manual removal using pliers, low- or high-speed carbide or diamond burs, stones, lasers, and ultrasounds, among others [5]. Although biotechnology has advanced, previous studies indicate that Italian, Iraqi,  and Brazilian orthodontists prefer to continue using rotary methods, despite the imminent risk of enamel wear [7, 9, 10].

Most of the available research on procedures used in bracket debonding and removal of remaining adhesive material are in vitro or laboratory studies [11-17]. Only few clinical studies exist due to difficulty in evaluating these variables in the mouth [18-21]. At the same time, there is a constant growth in the market of materials, instruments, equipment, and technology, many of which without sufficient scientific evidence for safe application [4, 5]. Therefore, the professional who performs a fixed orthodontic treatment is in a position to choose a clinical practice according to possibilities, knowledge, specialization, training, experience, preferences, trends, and ethics.

Objectives

The aim of the study was to evaluate the knowledge and clinical practices of bracket debonding among orthodontists and general dentists.

Material and methods

This cross-sectional study was approved by a research ethics committee with resolution No. 236-2024-USAT- FMED. Population included 4,567 orthodontists and 56,705 general dentists registered with the Peruvian Dental College.

Study sample was acceptable for 107 orthodontists and 107 general dentists, and was calculated using formula for difference of proportions in two groups, obtained from a pilot study; sampling was non-probabilistic according to snowball sampling method. Orthodontists and general dentists of either sex, who perform fixed orthodontic treatment at least once a week within their clinical practice were included. Orthodontists who were not registered with the Peruvian Dental College, orthodontists or general dentists who could not be identified or contacted through social networks, those who did not agree to participate in study, or who did not respond to invitation to participate up to three times, were excluded. An elimination criterion was established for professionals who agreed to participate and received the survey link but did not sent the required responses.

Identification and recruitment of professionals was carried out through social networks. Survey Monkey® software was used to generate an electronic version of instrument and generate a link to access survey. Depending on participants’ preference, a message was sent via WhatsApp or e-mail for a same-day response. In case of delayed response, first reminder was made after
five days, and two more attempts every seven days. Consequently, an adherence rate of 80.6% was obtained from professionals with respect to a total number of survey links sent.

A documentary instrument was developed for data collection: a 12-question multiple-choice questionnaire to assess knowledge and an inventory of five closed questions was employed to record clinical practices. First part of the instrument included purpose of the study, informed consent, personal data, and professional experience in fixed orthodontics; second part consisted of questions on knowledge of bracket debonding and available techniques; third part had questions about the most frequent practices in bracket debonding techniques and removal of remaining adhesive mate­rial. The questions and answers were developed based on previous studies, as shown in Table 1 [7-10].

The instrument was validated by a team of five experts. A confirmatory factor analysis was performed on 17 items corresponding to knowledge and practices, using comparative fit index (CFI). A value of 0.929 was obtained, confirming high content validity of the instrument. Internal consistency was evaluated using Cohen’s k coefficient, with knowledge dimension = 0.932
and practices dimension = 0.846. Regarding temporal stability, test-retest technique was used with Pearson’s correlation coefficient, obtaining knowledge dimension = 0.984 and practices dimension = 0.887.

Statistical analysis

Categorical responses were converted to numbers, saved in Microsoft Excel v. 2019 spreadsheets (Microsoft, Redmond, WA, USA), and entered into statistical software SPSS v. 25.0 (IBM Corporation, Armonk, NY, USA). A descriptive analysis used means and standard devia­tions for quantitative data, while absolute frequencies
and percentages were applied for categorical data. Spearman’s correlation coefficient was used for correlation analyses, and chi-square or Fisher’s exact test was utilized for association statistics. In addition, Tukey’s test was employed for multiple comparisons in three or more groups, with a significance level of 5%.

Results

Orthodontists participating in the survey were 43.73 ± 7.172 years old, while general dentists were 38.68 ± 7.771 years old. In terms of professional experience in fixed orthodontics, orthodontists reported  an experience of 12.45 ± 1.602 years, while general dentists had less experience, with 10.24 ± 0.836 years. In the orthodontists group, 71% were males and 29% females, while among general dentists, 77.6% were males and 22.4% females.

In case of orthodontists, majority showed a high  level of knowledge of bracket debonding, while minority had a low level, followed closely by intermediate level, as seen in Table 2. In the group of general dentists, a similar distribution of percentages was observed, with majority also having a high level of knowledge. For this reason, both types of professionals had a similar knowledge level (p = 0.628).

Table 3 presents that variables, i.e., age and sex, were not significantly related to knowledge of orthodontists. This was different for years of specialists’ experience, and were significantly and inversely related to knowledge of bracket debonding (p = 0.005). This result demonstrated that there was a tendency for orthodontists with fewer years of experience to achieve better knowledge scores. However, for general dentists, significant diffe­rences in knowledge were observed only between male and female participants (p = 0.038).

Table 4 shows multiple comparisons of orthodontists’ knowledge across age groups. Significant differences were found comparing the 25-37 years group with 38-49 years (p = 0.018) and 50-63 years (p = 0.002); however, there were no differences between older age groups (p = 0.256). Also, no differences were found in knowledge of general dentists when comparing different age groups (p > 0.05).

Table 5 presents the variation in orthodontists’ knowledge according to professional experience in a multiple comparison analysis. Significant differences were found when comparing the 20-28 years group with 3-10 years (p = 0.001) and 11-19 years (p = 0.001) of professional experience; however, there were no differences between two groups with less professional experience (p = 0.956). Knowledge of general dentists was also not different when comparing different groups of professional experience (p > 0.05).

Regarding practices on bracket debonding, similar and different response distributions were obtained between groups, as illustrated in Table 6. For both orthodontic specialists and general dentists, mechanical pressure technique with pliers was the most commonly used option for debonding brackets. Ultrasonic tips were the second most commonly used technique by general dentists, while laser technology was the second most commonly used method by orthodontists. However, these reported percentages were not sufficient to find significant differences between groups (p = 0.901). It was also shown that ceramic brackets, according to the practice of orthodontists and general dentists, were most frequently associated with damage to enamel during debonding. For orthodontists, metal brackets were less frequently associated with enamel damage, while general dentists indicated resin brackets with respect to lowest frequency of damage to enamel tissue. This allowed to confirm that there were differences between groups in terms of damage to enamel after debonding with type of bracket (p = 0.002). However, both orthodontists and general dentists reported a change in enamel color and shine as the most frequent damage observed after bracket debonding; the same proportion of response was observed in other alternatives, thus it was established as a non-significant difference (p = 0.450).

Table 6 shows that both orthodontists and general dentists most frequently reported using Arkansas’ stone as their main polishing material. Orthodontists selected a diamond bur as the least frequent choice, but general dentists chose a diamond bur as the second most frequent choice. These variations were reflected in a significant difference between groups regarding main material used for polishing after bracket debonding (p = 0.050). In the third place of frequency of response, orthodontists indicated not using any complementary material, while general dentists indicated using polishing brushes or not using any material. Consequently, differences were found with respect to the choice of complementary polishing material (p = 0.043).

Discussion

The majority of professionals in both groups demonstrated less frequently low knowledge level. However, knowledge of both orthodontists and general dentists varied differently with age, gender, and professional experience in fixed orthodontics. Among orthodontists, knowledge was inversely related to their experience, with differences mainly observed between specialists with less and more years of professional experience, which was consistent with differences in knowledge levels observed between younger and older specialists. This may be because less experienced and younger orthodontists are recent graduates, with fresh knowledge and practical details of various debonding techniques learned in training, whereas orthodontists with more experience may remember details of a protocol they have been using over the years [22]. This difference in professional experience or age does not seem to affect general dentists’ knowledge. In contrast, knowledge of general dentists appears to differ between men and women. This gender effect on general dentists’ knowledge may be associated with a shift from a predominantly male to a greater female participation in dentistry, which progressively influence knowledge, practices, and trends [23]. In general, high knowledge was expected in majority of specialists, similar to that reported by Ngan et al. [8] on knowledge of orthodontists in debonding. However, it was pleasing to find that general dentists had similar knowledge to specialists, considering few existing precedents. For example, Arunachalam et al. [22] also stated that general dentists may have good knowledge in procedures involving cementing/debonding, although Alshammari et al. [24] indicated important differences between specialists and general dentists.

In both groups of professionals, in terms of debonding techniques, the most frequently reported answer was the use of orthodontic pliers, regardless of bracket’s design. Orthodontists’ preference was followed by lasers and ultrasounds, while the order was reversed for general dentists. Despite disadvantages of orthodontic pliers regarding perceived patient pain, time spent, adhesive resi­due, and microfractures in enamel [6, 20, 21], it is still the preferred alternative because of its variety of designs, low cost, and some control of cutting and traction forces [9, 10, 15]. This preference for using pliers to debond metal brackets was also reported by Mahmood et al. [10]. According to Ngan et al. [8], it was the most commonly used technique by orthodontists for debonding ceramic brackets. However, studies such as Khalil et al. [17] showed that the use of lasers in debonding could decrease the risk of enamel damage, in addition to representing less procedure time, as stated in Bora et al. [6]. Although ultrasound was the second most frequently used option among general dentists, this technique did not demonstrate to have superior qualities to laser, as reported by Dalaie et al. [15] and Khalil et al. [25].

Brackets exhibit high resistance to shear forces, hence their removal represents an unavoidable risk of producing cracks or permanent damage to tooth enamel, which depends on etching protocol, resin used, tooth substrate, and debonding technique [13, 14]. It seems that the above is acknowledged by both types of professionals, who agree on the risk of enamel damage associated with ceramic bracket debonding, with consistency among ortho­dontists in identifying metal brackets as the option with the lowest risk of enamel damage. This may be because in debonding of ceramic brackets, the fracture line is located between enamel and adhesive material, while in metal brackets, it is situated between bracket base and adhesive [5]. Conversely, in this context, general dentists indicated resin brackets with the lowest risk of enamel damage. Nakada et al. [19] reported that resin brackets have a less compact base than that in ceramic brackets, thus produce less painful sensation during debonding; this could be of higher value for a professional, for whom reducing patient’s discomfort is more important than deciding for aesthetic brackets [18, 21].

Among alterations frequently observed after brackets  removal are changes in optical characteristics of enamel, which occur in 50% of patients with fixed appliances [14, 20]. In this regard, both professionals reported changes in color and shine of enamel as mostly observed. This suggests a greater frequency of slight damage or perhaps, no damage at all, which may coincide with Sfondrini et al. [9], who stated that majority of orthodontists did not detect any damage after bracket debonding. However, force applied through mechanical procedures to achieve debonding may cause fracture lines and/or cracks in enamel, especially when ceramic brackets are removed [3, 5]. Although minor lesions characterized by optical changes can be detected more frequently, both specialists and general dentists mentioned that increased use of debonding pliers may additionally be causing lesions and increase structural damage during removal of fixed appliances [4, 14].

Although debonding procedure has a significant impact, removal of adhesive material is a phase that produces the greatest amount of enamel loss [26]. In the present study, both groups of professionals agreed on using Arkansas’ stone more frequently for the remo­val of remnant material. However, orthodontists reported using diamond burs as last option, while general dentists apply the same rotary instrument as the second option. In this regard, it should be remembered that abrasion produced by any rotary instrument is operator-dependent, based on size, composition of particle, rotation speed, and pressure exerted [4, 5]. This choice can be justified by studies that indicate Arkansas’ stone as rotary instrument that produces less damage to enamel surface because of its lower abrasive capacity [27] as well as producing less temperature variation in pulp chamber [28]. However, there is also evidence that Arkansas’ stones and diamond burs produce greater enamel loss and temperature increase compared to multi-laminated tungsten carbide burs due to the number and smoothness of their blades [4]. In fact, some studies found that ortho­dontists prefer tungsten carbide burs at low or high speed [7, 9, 10], which contrasts with findings of the present study, where this tool was relegated to the third option of preference in both groups of professionals. This could be explained by the fact that despite knowing about the abrasion produced by high-speed rotating instruments [11, 12, 16], there might be a lack of knowledge about other techniques linked to the concept of minimal intervention, resistance to paradigm change, costs, familiarity of use, attitudinal barriers, perceptions, beliefs, etc., which could play a role in not adopting a more appropriate clinical protocol [29, 30]. For example, Barreto et al. [7] found that most orthodontists participating in their study used mainly high-speed rotary instruments, possibly due to shorter clinical time required for application, despite uncontrolled wear it may cause on enamel [4, 5]. The iatrogenic removal of enamel surface during the elimination of remaining adhesive, results in the exposure of enamel prism ends, and a significant increase in the number, length, and width of enamel cracks [5, 15]. These changes generate conditions for demineralization, weakening of the enamel, and exposure of dentin tubules to the external environment – conditions strongly associated with the formation of carious lesions and hypersensitivity following orthodontic treatment [31].

Both professional groups agreed on using rubber discs and SofLex discs as first and second choices when considering a complementary material for enamel surface polishing. However, it was striking that general dentists chose no complementary polishing option. This would not be advisable because of imperfections occurring on enamel during utilization of abrasive rotary instruments to remove remaining material. Regardless of agent type or instrument used, research indicate that supplemental polishing is highly necessary [4, 11, 32]. For example, Ghaleb et al. [12] found less enamel surface roughness when using tungsten carbide burs for primary polishing and rubber discs for supplementary polishing. This can explain preferences found among orthodontists and general dentists, similar to those reported by Mahmood et al. [10], although the second preference choice in both groups for the use of SofLex discs can also be justified [32].

Limitations of the study include the diversity of cli­nical debonding protocols available, which are not represented in this survey. The impossibility of random sampling limits the representativeness of respondents’ answers as well as cultural or national differences, which may limit generalizability beyond the target population. It should be noted that, as a self-administered survey, there was no objective clinical observation or triangulation with clinical records, which could lead to a risk of social desirability bias and recall bias. Future studies should include prospective observational cohorts with clinical verification of debonding techniques and enamel damage outcomes, randomized comparisons of in vivo removal methods, or qualitative interviews to further explore the rationale for decision-making.

Conclusions

Both orthodontists and general dentists who frequently perform fixed orthodontic treatment had similar knowledge of bracket debonding. For orthodontists, knowledge was inversely correlated with years of professional experience of performing fixed orthodontics, with significant differences in knowledge between specialists with greater and lesser experience, and similarly related to age. In general dentistry, knowledge appears to be related differently between males and females. In the responses regarding clinical practice, there were no differences in bracket debonding technique frequently used by both types of professionals as well as type of enamel damage they frequently observe after debonding; however, there were differences between orthodontists and dentists in choosing the type of brackets, which represented a greater risk of damage to enamel during debonding. Differences were also found with respect to polishing material frequently used by both types of professionals immediately after debonding as well as supplementary polishing material they chose to apply.

Disclosures

Author contributions: Conceptualization: J.R.N., M.O.P.; Methodology: M.O.P.;    Questionnaire adaptation: J.R.N., M.O.P.; Investigation and data collection:    J.R.N.; Formal analysis: M.O.P.; Data curation: M.O.P.; Writing of ori­ginal draft: J.R.N., M.O.P.; Writing – review and editing: J.R.N., M.O.P.; Supervision: M.O.P.; Project administration: J.R.N., M.O.P. All authors have read and agreed to the published version of the manuscript.

Funding: This research received no external funding.

Institutional Review Board statement: The study was approved by the Santo Toribio de Mogrovejo Catho­lic University, Peru (approval number: 236-2024-USAT-
FMED issued on 10 May 2024).

Informed consent statement: Not applicable.

Data availability statement: Not applicable.

Acknowledgments: None.

Conflicts of interest: The authors declare no conflicts of interest.

AI use statement: No artificial intelligence tools were used in the preparation of this manuscript.

References