Comparative Evaluation of Efficiency and Efficacy of Caries Excavation Burs in Pediatric Patients: A Randomized Clinical Trial

Abstract

Aims and background

To investigate and compare the cutting efficiency (time taken) and efficacy based on visual criteria, tactile criteria, and assessment by caries detecting dye of smart bur and diamond point in primary molars of children between 3 and 9 years. Dental caries is a progressive breakdown of tooth structure, often due to poor dietary habits in children. Traditional treatments like high-speed drilling can remove healthy tissue. Innovations like polymer burs made from polyether ketone ketone (PEKK) selectively remove decayed dentin based on hardness, reducing discomfort and preserving tooth integrity.

Materials and methods

This in vivo double-blinded, parallel randomized clinical trial compared the cutting efficiency and efficacy of smart bur and diamond point in primary molar caries removal. Participants were randomly assigned into two groups using a computerized generated sequence. Efficiency was timed; efficacy was assessed visually, tactually, and with caries detector dye.

Setting

Department of Pediatric and Preventive Dentistry, Government College of Dentistry.

Participants

A total of 60 patients following inclusion criteria.

Intervention

Occlusal caries in dentin was removed with two different caries excavation burs, followed by restoration with Type II glass ionomer cement.

Results (main outcome)

The diamond point was more efficient, with a mean time of 112.93 ± 27.56 seconds, compared to 128.40 ± 19.98 seconds for the smart bur. The diamond point revealed caries completely in 76.7% of cases, higher than 43.3% with the smart bur.

Conclusion

The smart bur serves as an effective aid in minimally invasive dentistry by preserving healthy tooth structure, but it does not surpass the conventional diamond point.

Trial registration number

REF/2025/06/107330.

Clinical significance

Smart burs, as a part of minimally invasive dentistry, preserve healthy tooth structure during caries removal. They may serve as an alternative to conventional caries excavation methods in pediatric dentistry.

Introduction

Dental caries is a prevalent condition primarily resulting from poor dietary habits, leading to the demineralization and breakdown of tooth structure. Traditionally, the management of caries involves the use of slow-speed handpieces and carbide burs, which often inadvertently remove healthy tooth tissue along with the decayed portions. This limitation has highlighted the need for more precise and conservative treatment approaches.

Minimally invasive dentistry (MID) is a patient-centered approach that focuses on preserving oral health through early detection, risk assessment, and conservative treatment strategies. It promotes collaboration between the dental team and the patient, emphasizing preventive care, minimal intervention, and regular follow-up. An essential component of MID involves guiding and encouraging patients to actively participate in caring for their own oral health and hygiene.¹ In MID, dental caries is understood as a dynamic infectious disease process, rather than being viewed solely as the end-stage manifestation of decay. This modern perspective replaces the traditional philosophy of “extension for prevention” with a more conservative and evidence-based approach, often summarized as “constriction with conviction.”²

Historically, dental burs were developed >3 centuries ago and remain widely used in modern dental practice. They can be employed at rotational speeds reaching up to 5,00,000 revolutions per minute.³ Ancient civilizations like the Maya, Greeks, and Romans used basic tools such as bow drills and trephines for dental procedures.⁴ In 1728, Pierre Fauchard described some of the earliest dental techniques, including the use of bow drills equipped with cutting tools. The 19th century saw hand drills with steel burs manually rotated by fingers. Though James Nasmyth created a flexible shaft in 1829, its dental value was unrecognized.⁵ Silicon carbide tools replaced ineffective carbon steel burs. The invention of the foot-pedal drill in 1871 and a ceiling-mounted version in 1883 improved usability. Steel burs produced by machines were introduced in 1891, followed by the invention of the diamond bur in 1897 and the development of high-speed rotary instruments in 1942.

In 2003, a notable development emerged from Boston with the introduction of a potential alternative to traditional dentinal caries removal methods. This innovation involved a new polymer prototype bur, which exhibited slightly lower mechanical properties compared to sound dentin.⁶ This marked a step towards more innovative and specialized approaches to dental care.

The development of smart bur II introduced notable improvements in both design and materials, enabling the bur to maintain its structural integrity and perform effectively at speeds of up to 5,000 rpm.

The current research aimed to examine and compare the cutting efficiency and efficacy of carious dentin removal when employing smart bur in contrast to the conventional diamond point method. This investigation was carried out within the primary molars of children between the age range of 3–9 years. The study sought to shed light on the performance of these two approaches in terms of their ability to remove caries effectively in primary molars (Fig. 1).

Fig. 1:

Diamond point and smart bur

Materials and Methods

Design

Double-blinded parallel randomized clinical trial registration number: REF/2025/06/107330 (Flowchart 1).

Flowchart 1:

CONSORT flowchart for randomized controlled trial

Procedure

This study was conducted over a period from 01/06/2023 to 30/11/2024 in the Department of Pediatric and Preventive Dentistry, following approval 168/IEC/SS/202 from the institutional ethical committee. A total of 60 children visiting the outpatient department were randomly selected and divided into two groups (30 each) based on the type of bur used for caries removal. Group allocation followed a 1:1 ratio, generated using www.randomizer.org. An independent person, not involved in the study, created the randomization sequence and used the sequentially numbered, opaque, sealed envelopes (SNOSE) method to maintain allocation concealment. Participants selected envelopes from boxes labeled A and B to ensure unbiased group assignment. The study followed CONSORT guidelines for planning and reporting of clinical trials.

Participants

Inclusion Criteria

• Children aged 3–9 years with good general health.

• Parent/guardian of the child provided informed and written consent.

• Children classified under Frankel behaviour rating scale 3 or 4.

• Right and/or left, maxillary and/or mandibular primary molars with occlusal caries extending up to dentin.

• Caries lesions diagnosed as ICDAS 2 Code 5: distinct cavity with visible dentin.

Exclusion Criteria

• Grossly decayed primary molars.

• Detection of clinical and/or radiographic findings or symptoms.

• Fractured/trauma to primary molars.

• Presence of developmental defects in primary molar.

• Children with underlying systemic disease.

Source

Data was obtained from the outpatient department at the Department of Pediatric and Preventive Dentistry.

Data Measurement

The study involved the excavation of demineralized dentin from primary molars using two different types of burs. The participants were categorized into two groups according to the type of bur utilized (Figs 2 and 3).

Figs 2A to F:

Procedural steps for group I: (A) Diagnosis of ICDAS Code 5 with WHO probe; (B) Dentin caries removal using diamond point; (C) Efficacy criteria 1: visual assessment; (D) Efficacy criteria 2: tactile assessment; (E) Efficacy criteria 3: assessment of stained dentin; (F) Postoperative

Figs 3A to F:

Procedural steps for group II: (A) Diagnosis of ICDAS Code 5 with WHO probe; (B) Dentin caries removal using smart bur; (C) Efficacy criteria 1: visual assessment; (D) Efficacy criteria 2: tactile assessment; (E) Efficacy criteria 3: assessment of stained dentin; (F) Postoperative

Group I—Pivo Diamond Point No. 08 (1.4 mm head diameter).

Group II—Smart Burs® II RA #4 (1.4 mm head diameter).

Following a preoperative clinical evaluation, teeth were isolated using a rubber dam after applying topical anesthetic. Lesions classified as ICDAS Code 5 were confirmed using a WHO single-end screening probe under adequate illumination. The cavity outline was prepared using a high-speed airotor handpiece with a nonend-cutting safety bur, enhancing visibility and removing unsupported enamel. Caries excavation was then performed with a slow-speed micromotor and contra-angle handpiece at 5,000 RPM, under continuous saline irrigation to protect the pulp. Caries removal was carried out until only firm dentin remained and the bur no longer penetrated the underlying healthy dentin. The excavation time for each sample was recorded using a digital stopwatch by a trained assistant (Table 1).

Table 1:

Master chart showing distribution of all the parameters for both the groups

		Males			Females			All subjects
Variable		Group I	Group II	p-value	Group I	Group II	p-value	Group I	Group II	p-value
Visual criteria	Presence of dentin discoloration	5	8	0.269	4	11	0.011*	9	19	0.010*
Visual criteria	Absence of dentin discoloration	10	7		11	4		21	11
Tactile criteria	Catch present over affected dentin	4	3	0.666	1	8	0.005*	5	11	0.08
Tactile criteria	Smooth passage of explorer	11	12		14	17		25	19
Dye score	Score 0	11	8	0.18	12	5	0.065	23	13	0.037*
Dye score	Score 1	1	4		1	5		2	9
Dye score	Score 2	2	0		2	4		4	4
Dye score	Score 3	0	2		0	1		0	3
Dye score	Score 4	1	1		0	0		1	1
Dye score	Score 5	0	0		0	0		0	0
Time required (seconds)	Mean ± SD	112.33 ± 30.532	126.20 ± 21.557	0.162	113.53 ± 25.306	130.60 ± 18.749	0.045*	112.93 ± 27.560	128.40 ± 19.976	0.016*

*p-value p < 0.05 statistically significant

Following the removal of caries, the efficacy of dentin excavation was assessed through both visual inspection and tactile examination. Visual inspection focused on the presence or absence of discoloration, while tactile assessment was performed using a dental explorer to detect a smooth base or any “catch” sensation within the cavity. To confirm complete removal of infected dentin, a caries detector dye was applied using a micro-applicator. After 10 seconds, the dye was rinsed off with water, and assessment was conducted by a blinded coinvestigator. Any stained areas were further excavated using a sharp spoon excavator. Upon completion of excavation, the cavity was restored with type II glass ionomer cement. Following restoration, occlusion was checked with articulating paper, and any high points were corrected using a GIC polishing kit (Fig. 4).

Figs 4A to D:

Assessment of both groups: (A) Assessment in terms of visual criteria; (B) Assessment in terms of caries detecting dye score; (C) Assessment in terms of tactile criteria; (D) Assessment in terms of time required

Bias

All clinical procedures were performed by a single operator to mitigate any potential procedural biases. Assessment of clinical parameters was done by another investigator.

Study Size

Sample size estimation was conducted using G*Power software (version 3.1.9.7), indicating that a minimum of 52 samples was required.

Thus, it was proposed to include 60 participants in the study.

Statistical Methods

Data were entered into an Excel sheet and analyzed using Statistical Package for the Social Sciences (SPSS) version 25.0.

The Kolmogorov–Smirnov test was used to evaluate the probability distribution of the data.

Age was found to be nonnormally distributed, while time followed a normal distribution.

Intergroup comparisons of continuous variables were conducted using the independent t-test for time and the Mann–Whitney U test for age.

In order to compare categorical variables, the Chi-square test was employed. A p-value of <0.05 was considered statistically significant.

Results

In group I, 30.0% of the children exhibited dentin discoloration, while 70.0% showed no discoloration. In group II, the prevalence of dentin discoloration was notably higher, with 63.3% of children showing discoloration, and 36.7% having no discoloration. The presence of dentin discoloration was significantly greater in group II compared to group I.

Among all the subjects, 16.7% of the children in group I and 36.7% of those in group II exhibited a catch over the affected dentin when examined using tactile criteria. However, the difference between the groups in terms of the presence of catch was statistically nonsignificant (p = 0.080).

Among all subjects, the majority had a dye score of 0 (60.0%). In group I, 76.7% of the subjects had a score of 0, while in group II, only 43.3% had this score. Conversely, group II had a significantly greater number of subjects with a dye score of 1 (30.0%), compared to 6.7% in group I. The difference in dye scores between the two groups was statistically significant (p = 0.037).

Among all subjects, the mean time required to perform the procedure was 112.93 ± 27.560 seconds in group I and 128.40 ± 19.976 seconds in group II. The time taken was significantly greater in group II compared to group I, with a p-value of 0.016, indicating a statistically significant difference between the two groups.

Discussion

Dental caries is one of the most prevalent diseases in the pediatric population, significantly affecting the oral health and well-being of children. In primary teeth, the spread of dental caries within the dentin follows the unique tubular structure of this tissue. Dentin tubules are more numerous and have a larger diameter near the dental pulp, becoming progressively narrower toward the dentinoenamel junction (DEJ). This structural arrangement plays a key role in the progression of carious lesions.

Traditionally, tungsten carbide burs were commonly used for caries removal due to their efficiency, but they are associated with higher pain scores during the procedure.⁷ Diamond points are particularly effective in removing soft, decayed tissue while leaving behind harder, unaffected tooth structure. This characteristic makes them ideal for selective caries excavation. However, they are often slower compared to traditional burs, as their cutting action is less aggressive. Diamond points can generate heat during the excavation process, which may cause discomfort for the patient if not properly managed. The need for frequent cooling and the slower cutting speed are factors to consider when selecting diamond points for caries excavation.⁸

Banerjee et al.⁹ reported that conventional burs were the fastest caries removal method (57.1 seconds), while the present study showed a longer time of 112.93 seconds with diamond points. Gunjal et al.¹⁰ reported that polymer burs were faster when compared to enzymatic gel, taking an average of 3.8 minutes per tooth. Several studies have evaluated the efficiency and effectiveness of polymer burs in caries removal, with varying outcomes. Celiberti et al.¹¹ reported a mean removal time of 2 minutes ± 20 seconds in primary teeth, which is comparable with the present findings. Dammaschke et al.¹² and Meller et al.¹³ also found no statistically significant difference in excavation times between polymer and carbide burs (p > 0.05). In contrast, the present study demonstrated a statistically significant difference (p < 0.05), with polymer burs requiring a longer mean time (15.47 seconds) compared to diamond points.

According to the findings of Allen et al.,¹⁴ caries removal using polymer burs took 14.7 minutes, contrasting with the current study, in which less time was required by the polymer bur (2.14 ± 0.33 minutes). According to Vijay et al. and Shakya et al., the average time required for caries removal was 133.50 seconds when using a polymer bur, compared to 111.0 seconds with a diamond point.^15,16 Goyal et al.¹⁷ reported that the minimum time taken to remove carious dentin by Smart Bur was 260 seconds, while by diamond point it was 250 seconds. Faiek et al.¹⁸ reported that the mean time required for caries removal using SmartPrep burs was 2.8 ± 0.4 minutes. Thomas et al.¹⁹ mentioned that SmartPrep burs required the longest time for caries excavation, with a mean duration of 4.86 ± 0.31 minutes.

Prabhakar et al.²⁰ found that 65% of lesions treated with polymer burs achieved complete caries removal, compared to 100% with carbon steel burs (p < 0.001). In the present study, only 43.3% of lesions treated with polymer burs showed complete caries removal. According to a study by Soni et al., the mean value of efficacy of caries removal using caries detector dye in the Smart Bur group was 0.47 ± 50. There was a statistically significant difference (p < 0.05).21 Consistent with the aforementioned findings, 36.6% of cases showed complete caries removal by Wahba et al., while 43.3% of cases showed incomplete caries removal.²² Aswathi et al.²³ revealed that 92% of lesions showed complete removal of caries by Smart Bur after the application of caries detector dye. In the current study, 43.3% of subjects showed complete removal of caries in the Smart Bur group.

According to a study by Thomas et al.,¹⁹ polymer burs had the least efficiency, with only 6.7% reaching a score of 2 and none achieving a score of 0. Maarouf et al.²⁴ showed significantly higher scores for caries detector dye for the polymer bur group (p = 0.016). In the present study, score 4 was found in 3.3% of cases, score 3 in 10%, score 2 in 13.3%, and score 1 in 30% of cases.

Limitations

The present study did not evaluate parameters such as postoperative sensitivity, long-term outcomes, patient comfort, and microbiological efficacy, which could provide a more comprehensive assessment of the excavation techniques. Additionally, advanced diagnostic tools such as Diagnodent, Quantitative Light-Induced Fluorescence (QLF), Near-Infrared Transillumination (NIRT), Fiber-Optic Transillumination (FOTI), and Dye-Enhanced Laser Fluorescence (DELF) were not used for cavity assessment. Future studies with larger sample sizes, longer follow-up periods, and advanced diagnostic methods are recommended to obtain more precise and clinically relevant outcomes..

Conclusion

The Smart Bur serves as an effective aid in minimally invasive dentistry by preserving healthy tooth structure, but it does not surpass the conventional diamond point.

Clinical Significance

Smart burs, due to their polymer composition, generate less heat during caries removal—potentially reducing thermal damage and patient discomfort. Diamond points demonstrated superior efficiency and efficacy in caries removal. Clinically, Smart burs may be preferable in situations where patient comfort is a priority, such as in minimally invasive procedures or the treatment of anxious pediatric patients.

Author Contributions

All authors contributed significantly to the conception, drafting, and revision of the manuscript. Clinical management, data collection, literature review, and final approval of the manuscript were carried out collectively by the authors.

Acknowledgment

The authors would like to acknowledge the support and cooperation of the patient and guardians for providing consent for treatment and related clinical images.

AI Disclosure

Artificial intelligence–based language assistance (QuillBot Version 3.19.0) was used only for grammatical refinement and language editing during manuscript preparation. No AI tool was involved in clinical decision-making, data interpretation, or generation of scientific conclusions.

Orcid

Riya A Pursnani https://orcid.org/0009-0007-2743-5521

Ashish Saxena https://orcid.org/0000-0001-9846-7095

Shikhar P Chauhan https://orcid.org/0009-0002-4381-287X

Data Availability

The data supporting the findings of this study are available within the article. No additional datasets were generated or analyzed during the current study.