Comparative Evaluation of Effectiveness of Benzocaine Gel and Ice for Pain Management in Children during Local Anesthetic Administration by CCLAD: A Randomized Controlled Trial

Abstract

Aims and background

Managing dental pain in pediatric patients is crucial for successful treatment and reducing anxiety. Methods such as topical anesthetics, distraction techniques, and computerized systems such as the “WAND” help reduce discomfort during local anesthetic administration. However, cryotherapy for precooling injection sites is cost-effective and potentially more effective alternative to traditional topical medications. The aim of this study was to evaluate and compare the effectiveness of ice and benzocaine gel as topical agents for pain management during local anesthetic administration via a computer-controlled local anesthetic delivery (CCLAD) system.

Materials and methods

A split-mouth, single-blinded, randomized controlled clinical trial was conducted involving healthy children aged between 5 and 10 years who required maxillary bilateral local anesthesia for dental procedures. The objective pain was measured using the Modified Behavioral Pain Scale during the administration of local anesthetic via CCLAD, with the application of topical agent, ice, and benzocaine gel. Moreover, subjective pain was evaluated using the Wong–Baker Faces Pain Rating Scale.

Results

The topical ice group showed a lower Wong–Baker Facial Pain Scale score compared to the group using benzocaine gel; however, the observed difference was not statistically significant. Topical ice application showed a lower modified pain scale score compared to the benzocaine gel group; however, the observed difference was not statistically significant.

Conclusion

Topical ice shows better results when compared to benzocaine topical anesthetic gel. Topical ice application along with CCLAD is an almost zero-pain injection technique in pediatric dentistry.

Clinical significance

Pain management during local anesthesia injection is a critical step in gaining initial trust during dental treatment. Precooling the injection site with cryotherapy is beneficial in reducing pain before local anesthesia injection in pediatric patients.

How to cite this article

Ninawe N, Anija CK. Comparative Evaluation of Effectiveness of Benzocaine Gel and Ice for Pain Management in Children during Local Anesthetic Administration by CCLAD: A Randomized Controlled Trial. Int J Clin Pediatr Dent 2025;18(1):19–23.

Introduction

Managing dental pain in pediatric patients is of utmost importance when providing dental treatments and performing invasive interventions. The administration of local anesthesia through injection is typically a procedure that induces anxiety and has the potential to elicit behavioral issues in patients, particularly in young individuals.¹ Several strategies have been suggested to minimize the discomfort associated with the administration of local anesthetic agents. These include applying topical anesthetics, employing distraction methods, using counter-irritation techniques, warming the anesthetic solution, modifying the infiltration rate, buffering the anesthetic, and slowing down the injection process. Various studies have documented diverse efforts undertaken by researchers to attain local anesthesia procedures that are devoid of pain. The “WAND,” a computerized system for delivering local anesthesia, has emerged as a potential solution for significantly reducing or eliminating the discomfort associated with dental injections. This system ensures consistent, slow delivery of anesthesia at a controlled pressure, regardless of tissue resistance. According to the manufacturer, the device administers the anesthetic at a rate designed to remain below the threshold for pain.^2,3 While a computer-controlled local anesthetic delivery (CCLAD) system effectively manages pain, it is important to note that the discomfort related to needle insertion may still persist. The application of a local anesthetic agent remains crucial, even in the case of the WAND, to ensure effective pain management. Over the years, there has been consistent application of topical anesthetics in dentistry for the meticulous preparation of injection sites before needle penetration. While some research has demonstrated that topical anesthetics can effectively reduce discomfort during injections, it is noteworthy that other studies have found that their effectiveness is no more than that of a placebo. However, recently, the application of cryotherapy has gained recognition as a recommended strategy for diminishing pain perception in patients. This approach not only proves to be effective and efficient but also stands out as a cost-effective alternative and can potentially replace the use of topical medication. Notably, research studies have indicated that precooling the injection site is associated with a reduction in swelling, nerve signaling speed, cellular processes, and regional blood circulation. The application of ice not only offers physical advantages but also supports the psychological comfort of patients by potentially distracting them from focusing on discomfort. The utilization of ice not only provides physiological benefits but also contributes to the psychological well-being of patients by potentially diverting their attention from focusing on discomfort.⁴

Materials and Methods

Trial Design and Study Setting

This was a split-mouth, single-blinded, randomized controlled clinical trial performed in healthy children aged between 5 and 10 years who required maxillary bilateral local anesthesia for dental treatments.

The study population was selected from the outpatient department of Pediatric and Preventive Dentistry at Government Dental College and Hospital, Nagpur. Both parents and children were briefed about the study, and informed consent was obtained prior to participation. After assessing eligibility, 20 children were enrolled in this study. During the first visit, patient details were evaluated using a patient assessment form, and the children eligible as per the inclusion criteria were selected. Healthy children [American Society of Anesthesiologists (ASA) I] aged 5–10 years were selected if they required maxillary buccal infiltration anesthesia for dental procedures such as extractions, restorations, crown preparations, or pulp therapy in both quadrants.

Inclusion Criteria^{4 6}

• Healthy children (ASA I) aged 5–10 years.

• Children requiring maxillary buccal infiltration anesthesia for dental procedures (extractions, restorations, crown preparations, pulp therapy) in both the quadrants.

• Frankl's behavior rating scale grade III or IV.

• Children who were not using any analgesics or other medications that could affect their pain perception.

• Children whose parents provided informed consent to participate in the study.

Exclusion Criteria^{4 6}

• Medically compromised condition.

• Any history of allergic reactions to local anesthesia.

• Presence of active infection or pathology at the injection site.

• A history of previous dental treatments.

• Frankl's behavior rating grade I or II.

• Children with cold hypersensitivity.

The sample size for this study was estimated using data from a previous study by Mohiuddin et al.⁷ The predicted sample size per side was 20. They were randomly divided into two groups using computer-based randomization, and for the selection of the side and group of topical agents, allocation concealment using sequentially numbered opaque sealed envelopes was used. Because of the study design, neither the operator nor the patient was blinded, but the data analyst was blinded. Two groups were formed for the study: Group I received local anesthesia through the “CCLAD” method (Fig. 1) following the application of ice as a topical agent (intervention treatment), while group II underwent local anesthetic administration with the “CCLAD” after the application of benzocaine gel as a topical agent. At the first visit, half of the population according to randomization received local anesthetic administration with the “CCLAD” after the application of ice as a topical agent (intervention treatment). After 7 days, the same patients were recalled, and local anesthetic administration with the “CCLAD” after the application of benzocaine gel as a topical agent was done (control treatment) (Fig. 2). The other half of the population according to randomization received control treatment, and after 7 days the same patients were recalled and intervention treatment was given. An Eppendorf tube was chosen to prepare the ice pack, which was filled with saline and placed in the freezer. The temperature of the ice pack was maintained between −4°C and 0°C to prevent the risk of frostbite, and the temperature of the ice before application was confirmed using a thermocouple. A cotton roll was applied to dry the oral mucosa for 30 seconds, followed by the application of the ice pack to the buccal mucosa for 2 minutes.⁴ For the control group, where topical benzocaine gel was used, the mucosa was dried with a cotton roll for 30 seconds and topical anesthetic benzocaine (20%) was applied for 1 minute using a cotton applicator bud. After these procedures, local anesthetic administration was done using a CCLAD system. The objective pain was evaluated by another investigator, and the procedure was video recorded to minimize inter-examiner variability. Subjective pain was analyzed using the Wong–Baker Faces pain rating scale, and objective pain was measured using the Modified Behavioral Pain Scale (Table 1).

Fig. 1.

Computer-controlled local anesthetic delivery system

Figs 2A and B.

(A) Ice application before infiltration with CCLAD; (B) Infiltration with CCLAD after application of ice as topical agent

Table 1.

Modified Behavioral Pain Scale

Parameter	Finding	Points
	Definite positive expression (smiling)	0
	Neutral expression	1
Facial expression	Slightly negative expression (grimace)	2
	Definite negative expression (furrowed eyebrows; eyes closed tightly)	3
	Laughing or giggling	0
	Not crying	1
Cry	Moaning quietly; vocalizing gentle or whimpering cry	2
	Full crying or sobbing	3
	Full crying more than baseline cry (scored only if child was crying at baseline)	4
	Usual movements and activity	0
	Resting and relaxed	0
	Partial movement (squirming, arching limb; tensing, clenching)	2
Movements	Attempt to avoid pain by withdrawing the limb where the puncture is done	2
	Agitation with complex/generalized movements involving the head, torso or other limbs	3
	Rigidity	3

Modified Behavioral Pain Scale = SUM (points for all three parameters); 0, minimum score; 10, maximum score

Statistical Analysis

Data were analyzed using SPSS software. The level of significance was kept at 5%. Intergroup comparisons were done using the Mann–Whitney test.

Results

When comparing the Wong–Baker Facial pain scale scores between two groups, the mean scores were 1.00 ± 1.03 and 1.50 ± 1.27 for the topical ice and benzocaine gel groups, respectively (Fig. 3). Despite the topical ice application showing a lower Wong–Baker Facial pain scale score compared to the benzocaine gel group, the difference was not statistically significant (p = 0.220), as indicated in Table 2. Additionally, when comparing the modified pain scale scores between the two groups, the mean scores were 2.15 ± 0.37 and 2.35 ± 0.59 for the topical ice and benzocaine gel groups, respectively (Fig. 4). Although the topical ice group showed a slightly lower modified pain scale score compared to the benzocaine gel group, the observed difference was not statistically significant (p = 0.240), as outlined in Table 3.

Fig. 3.

Comparison of Wong–Baker Facial pain scale among two groups

Table 2.

Comparison of Wong–Baker Facial Pain Scale among two groups

Group	Mean ± SD	Mean rank	p-value
Topical ice	1.00 ± 1.03	18.50	0.220
Benzocaine gel	1.50 ± 1.27	22.50

Mann–Whitney test; p < 0.05 is statistically significant

Fig. 4.

Comparison of modified pain scale among two groups

Table 3.

Comparison of modified pain scale among two groups

Group	Mean ± SD	Mean rank	p-value
Topical ice	2.15 ± 0.37	18.93	0.240
Benzocaine gel	2.35 ± 0.59	22.08

Mann–Whitney test; p < 0.05 is statistically significant

Discussion

Local anesthesia plays a pivotal role in dentistry, facilitating effective treatment. In pediatric dentistry, alleviating emotional distress and fear during dental treatments is significantly improved by the administration of local anesthetic.⁸ Needle phobias, particularly the fear of pain from needle pricks, are frequently observed in children, compromising their dental health.⁹ To address this issue, various pharmacological and nonpharmacological techniques have emerged. Among these methods, topical anesthetics are widely recognized as the most prevalent and easily obtainable option.¹⁰ Moreover, the topical use of ice packs to alleviate pain is commonly employed in the treatment of sprains, injuries from burns, soft tissue bruising, insect bites, and musculoskeletal aches.¹¹ This study included the use of ice as one of the test groups, considering its established efficacy in pain reduction, ease of shaping to fit specific areas, and cost-effectiveness. Additionally, local anesthetic was applied using a computer-controlled local delivery (CCLAD) system after the application of ice or benzocaine gel. Although the computer-controlled local anesthetic system reduces pain perception, the needle insertion pain persists. Hence, this approach aimed to minimize pain perception and promote good behavior during the anesthetic injection process. Similarly, in a study performed by Anantharaj et al.,¹² the effectiveness of ice precooling, clove–papaya gel, and benzocaine gel as topical anesthetics in children was analyzed. The study results revealed that the benzocaine group exhibited the highest mean Wong–Baker Faces Pain Rating Scale (WBFPRS) score, followed by the clove–papaya group, and then the ice cone group. Conversely, the ice group displayed the lowest mean Sound Eye Motor (SEM) scale score, followed by the benzocaine group, and then the clove–papaya group.

Numerous facial rating scales have been specifically designed for use with young children. Among these, the Wong–Baker Faces Pain Rating Scale stands out for its simplicity, reliability, and demonstrated strong positive correlation. This scale has been widely employed to evaluate pain in both pediatric and adult populations across various studies.⁷ Therefore, the Wong–Baker Faces Pain Rating Scale was adopted in the present study for evaluating subjective pain, while objective pain levels were evaluated using the Modified Behavioral Pain Scale. Likewise, a study by Garret-Bernardin et al.¹³ evaluated pain experience and behavior during dental injections in children and adolescents. The researchers compared the CCLAD computerized delivery system with conventional local anesthesia. Moreover, the study concluded that the CCLAD system might offer a less painful injection experience and be better tolerated than conventional local anesthesia delivered through a traditional syringe.

In this study, maxillary buccal infiltration was considered, and it was found that the topical ice application showed a lower Wong–Baker Facial Pain Scale score compared to the benzocaine gel group; however, the difference was not statistically significant (p = 0.220). Additionally, when comparing the modified pain scale scores between the two groups, the topical ice group showed a slightly lower score compared to the benzocaine gel group.

In this study, CCLAD was used instead of normal injection technique as it is more comfortable in children. Furthermore, the penetration pain of needle during CCLAD was successfully managed by using topical ice application and showed it is better than benzocaine gel. Applying cold topically is thought to activate inhibitory pain pathways via myelinating A fibers, hence increasing the threshold for pain. It reduces metabolic rate, slows nerve conduction, induces transient constriction of superficial circulatory vessels and thus reduces the amount of blood needed by cells that were not initially engaged in the damage. All these effects work together to regulate the degree of inflammation and edema.^7,14 Lakshmanan and Ravindran⁴ showed that precooling the injection site with cryotherapy significantly lowers pain scores, assessed subjectively [Visual Analog Scale (VAS)] and objectively (SEM scale), compared to topical anesthetic gel in pediatric patients. A study conducted by Amrutha Varshini¹⁵ stated that cooling the injection site with ice prior to the injection offers comparable pain relief to topical anesthetic gel. In the present study, topical ice application was compared with 20% benzocaine gel. Moreover, the study was a split-mouth design, allowing to compare pain perception at two different times. The study revealed that subjective and objective pain scores were lower in ice group when compared with benzocaine gel; however, they were not statistically significant. The patient was more comfortable with the application of ice compared to benzocaine gel.

Conclusion

Topical ice shows better results compared to benzocaine topical anesthetic gel. When combined with CCLAD, topical ice application can be considered an almost zero-pain injection technique in pediatric dentistry. This approach simplifies patient management during injection time without the need for applying a medicament.

Clinical Significance

Effective pain control during local anesthetic injection plays a key role in establishing trust at the beginning of dental treatment. Cryotherapy before local anesthetic injection is helpful in alleviating pain at the injection site in pediatric patients.

Orcid

Nupur Ninawe https://orcid.org/0000-0003-1403-4634

Anija CK https://orcid.org/0009-0002-8153-2895