A Comparison on Efficiency and Aerosol Generation between "Modified and Conventional Technique of Bracket Bonding".

Introduction: The novel COVID-19 which spread's primarily through oral and nasal passage poses a major threat of spread during dental treatments. It is important for dental practitioners to use minimal aerosol techniques. The aim of this study is to compare the time taken, efficiency and aerosol generated between modified and conventional technique (CT) of bracket bonding.
Methods: This study includes 40 patients who required complete orthodontic treatment. In all 40 patients, one of the arches was bonded with modified technique (MT) and the opposing with CT. The time taken to prepare tooth in both the techniques were accessed. The efficiency of bond was seen over a period of 6 months. The amount of aerosol particulate matter generated during CT and MT was observed using a laser air quality monitor.
Conclusion: There is no significant difference in the bond failure and time taken between both the techniques. The aerosol generated in MT was minimal or almost negligible when compared to the use of CT. Copyright:

INTRODUCTION

During the pandemic, people affected with COVID-19 exhibited symptoms such as fever, sore throat, cough, joint pains, headache, diarrhea, loss of taste, anosmia, and in severe cases breathlessness.[12]

The salivary gland of human being is rich in angiotensin-converting enzyme 2 receptors to which the SARS-CoV-2 binds. This increases the risk of transmission of COVID-19 through respiratory droplets in the air, to nearly 6 feet.[3]

The oral-nasal pathway can channel the particles which are more than 10 μ in size. The particles which are 2.5 μ in size and lesser can carry organisms, such as SARS-COV-2 and enter the alveoli.[4]

Our dental and orthodontic practice came to a halt on January 2020 by the World Health Organization due to the widespread of COVID-19. During this time, only emergency situations such as trauma, Road traffic accident (RTA), and infections were undertaken with a meticulous amount of precautions and preparations.

In orthodontic practice, bonding of bracket creates aerosol and it was required to come up with alternative methods. The aim of this study is to compare the time taken, efficiency, and aerosol generation between modified and conventional technique (CT) of bracket bonding.

METHODS

A total of 40 patients (800 teeth) who required full moth orthodontic treatment were selected for this study. In all the selected patients, one of the arch was bonded with CT and the opposing with modified technique (MT). All 40 had a full complement of teeth, good oral hygiene. Patients with fixed partial dentures, veneers, syndrome and missing teeth were excluded from this study.

The patients and the treating doctor followed the COVID precaution's such as checking of temperature, distance of 6 feet, use of 0.2% povidone iodine mouthwash mixed with 1% hydrogen peroxide prior to treatment, N95, face shield and surgical gown.[56]

In the MT the teeth were first etched with 37% phosphoric acid for 20 seconds and washed with plain water using a 10 ml syringe with its needle removed instead of three-in-one-air-water syringe as in CT. A high volume suction was used throughout the treatment. Isolation was achieved using cotton rolls and the teeth was dried by dabbing a sterile gauze pack on the tooth surface [Figures 1 and 2].

Figure 1

Armamentarium

Figure 2

Steps in modified technique

The time taken for the tooth was recorded from the start of etching process of white frosty appearance. The efficiency of both the technique was observed over a time period of 6 months. A deboned bracket was considered as bond failure. The aerosol generated was measured using a Kaiterra laser egg [Figure 3]. This monitored was placed half a meter away from the patient and the particulate matter 2.5 micron was recorded prior and during the procedure. This laser egg categorizes the particulate matter in categories such as good (0–12) moderate (13–35) and unhealthy (35 and above).

Figure 3

Laser egg quality monitor

RESULTS

In the clinical evaluation of 800 teeth (40 people), 400 teeth were bonded using CT and 400 with MT chemically modified tetracycline. The time taken from the start of procedure T1 to appearance of frosty white T2 was recorded using a stop watch.

The time taken from the start of procedure to the white frosty appearance and the bracket failure between the two methods were calculated using the Chi-square test. The P 0.0663 and 0.0833 indicates no significant difference between the two techniques for time taken and bracket failure, respectively [Tables 1 and 2]. The test of significance used to find the difference in aerosol generation was calculated using the independent t test. The P 0.001 shows a significant difference between the techniques. More amount of aerosol was generated in CT with the use of three-in-one-air-water syringe compared to the MT [Table 3].

Table 1

The time taken from the start of procedure to the white frosty appearance

Variable	n	Mean	SD	P25	Median	P75	Minimum-Maximum	P
CT T1-T2	40	4.49	0.35	4.23	4.40	4.64	4.00-5.20	0.0663
MT T1-T2	40	4.67	0.36	4.48	4.56	4.86	4.13-5.40

CT: Conventional technique, MT: Modified technique

Table 2

Bracket failure

COVID status	Failure rate	Total bracket bonded	Percentage of failure (95%-CI)	Failure P
CT	8	400	2	0.0833
MT	2	400	0.5

CT: Conventional technique, MT: Modified technique, CI: Confidence interval

Table 3

Aerosol generation

Technique	n	Pretreatment PM2.5 mean	During procedure PM2.5 mean	SD	P
MT	40	7.35	6.45	0.876	0.001
CT	40	6.95	14.33	0.944

CT: Conventional technique, MT: Modified technique, SD: Standard deviation

DISCUSSION

The novel COVID-19 which spread's primarily through oral and nasal passage poses a major threat in the dental treatments. During March and early April 2020 due to the tremendous spread of COVID-19, all the dental procedures were put on hold except for emergencies like poking wire and broken appliances. Then, in late April and May, nonaerosol procedures were started with great precaution. Most of the patients undergoing treatments were youngsters and a halt to their treatment led to increase in appliance breakage, gingival swelling and distress. In order to advance, it was important for a dentist/orthodontist to protect both themselves and the patient by the use of appropriate personal protective equipment and to innovate a minimal or a nonaerosol techniques. The steps in conventional bonding technique for bonding brackets require the use of aerosol (three-one-air-water syringe.) to ensure that the tooth surface is dry. The easiest and clinically proven and approved method is to use a self-etching primer (SEP). During the COVID pandemic, the SEP could not be purchased due to temporary stop in courier service which led to a modified bracket bonding technique.[7]

In this study, the bonding of bracket was modified in such a way that aerosol was reduced to minimum and also at a very low cost. Meticulous precautions were followed in the hospital to avoid the spread of COVID-19.

Some studies investigated the influence of different etching times on bracket bond failure rate, and the results indicated no significant difference in bond failure rate between groups using 37% phosphoric acid etching for 15 s versus either 30 s or 60 s.[8910] In this study, the tooth was etched for 20 s after which it was washed and dried. In this study, there was no difference in the time taken for the appearance of white frosty enamel to appear in CT and MT technique was statistically not significant.

Previous studies have shown that most bond failures occur within the first 3 or 6 months of bracket placement.[1112] It was elaborated that it could be due to any deficiencies in the bond strength of any individual bracket/adhesive combination that would become evident within this initial period of treatment. Second, the initial period of treatment is also a time during which acclimatization and experimentation by the recipients in regard to the type of food that the orthodontic appliances can tolerate is noted. Finally, the initial phase of treatment may involve a period of depression in overbite from heavy occlusal forces. Henceforth, this study focused on the failure rates within the first 6 months and the patients were evaluated on a monthly basis.

In this study, bond failure was found to be nonsignificant in case of MT when compared to CT. The bond failure in CT was 2% and MT was 0.5%. The four failed bracket in the CT included two premolars, a canine and an incisor. The one failed bracket in the MT was in associated with premolar teeth. The increased bond failure in the CT might be due to lack of proper follow-up during the lockdown period. The bond failure rate was found to be lower for incisors and canines compared with premolars which was similar to the findings of Kinch, Newman GV and Zachrisson BJ.[131415] The reasons for this phenomenon were mentioned as a result of moisture contamination and trouble in accessing the posterior tooth for bonding during clinical procedures. In addition, Lovius et al. also suggested that the micromechanical bond properties of premolars might have been adversely affected because of a larger amount of prismatic enamel on these teeth.[15]

This modified nonaerosol technique (MT) has a very less bracket failure [Table 2]. The time taken for the tooth to be prepared for bonding brackets also is the same as the CT [Table 1].

Feng et al. found that there was a positive correlation relationship between PM2.5 particulate count and viral transmission.[16]

Wang and Du have found that aerosol may plays a major role in the spread off SARS-CoV-2 virus.[15] Moreover, smaller aerosol particles have greater potential to cause alveolar tissue infection of the lower respiratory tract when inhaled. The evaluation of aerosol generation with laser air pollution monitor showed that the use of syringe to prepare tooth for bonding produced less aerosol when compared to three-one-air-water syringe [Table 3]. This is a very simple and effective method which can be followed when the aerosol needs to be reduced during bracket bonding.

CONCLUSION

The bond failure and the time for tooth preparation taken in MT was statistically not significant when compared to that of the CT

The use of this MT can effectively reduce aerosol and provide a safe environment during bonding for both the treating doctor and patient.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.