Abstract
Background
In pediatric patients, it is of utmost importance to deal with pain during invasive and noninvasive dental procedures. In this study, two different local anesthesia delivery systems—Star Pen and Buzzy—were compared to the traditional syringe in reducing pain and apprehension in children aged between 5 and 10 years.
Aim
To evaluate and compare the pain levels and anxiety levels while local anesthesia is being delivered using Star Pen and Buzzy system in children between the ages of 5 and 10 years.
Materials and methods
Children between the aged 5 and 10 years were recruited, who were randomly split into three different groups—group I: Star Pen, group II: Buzzy, and group III: Conventional syringe. Local anesthesia was administered, followed by standard extraction procedures. Anxiety and pain measurements were recorded using Venham's Picture Test (VPT), face, leg, activity, cry, consolability (FLACC) scale, Animated Visual Pain Rating Scale, and pulse oximeter to measure pulse rate and oxygen saturation.
Results
Star Pen and Buzzy group showed lower pain and anxiety scores; lower post-treatment pulse rates were found in the Buzzy group, whereas Star Pen group showed lower VPT and FLACC scores.
Conclusion
Star Pen and Buzzy systems can be used as effective adjuncts in pediatric dentistry to reduce pain and apprehension.
How to cite this article
Prerana M, Shivanna V, Setty JV, et al. Comparison of Pain and Anxiety Levels with Two Different Local Anesthesia Delivery Systems in Children: A Randomized Clinical Trial. Int J Clin Pediatr Dent 2026;19(4):492–498.
Keywords: Anxiety, Buzzy, FLACC, Pain, Star Pen
Introduction
Pain is elucidated as a displeasing sensory or emotional feeling in association with true or possible tissue injury or described in terms of such injury.1 Local anesthetic administration is a procedure to reduce dental related pain. However, children have a deep-seated dread of sharp and pointed objects; hence, administering local anesthetic is itself a challenge in these patients.1
Walsh and Hmud described the “4S factors” for a child's dental apprehension, which comprise sights (sight of injection), sounds (sound of dental drill), sensations (high frequency vibration), and smells (bonding agents and eugenol).1 For majority of youngsters, dental fear and anxiety (DFA)—the anxiety related to dental procedures and fear of dental visits are serious concerns. In addition to this, DFA can lead to occupational stress for dentists and commonly leads to conflict among dental clinicians and outpatients or parents.1
In recent times, precooling injection area is a method devised to reduce pain during injection. Applying a cold stimulus at the injection location before the deposition of local anesthesia is a simple, economic, and physiologically efficient process.1 The premise that pain depends on child's attentiveness and awareness as an intellectual component is the sole criteria for the employment of both cooling (temperature) and vibration (stimulation). A “masking effect of pain” is made possible by including vibration, which additionally muddles the signal reception of the pain pathway along with cold stimulus.1
The Buzzy is a device of a kind that employs vibration and cold to lessen needle-related discomfort. Buzzy comprises of a body that vibrates and wings that are cooled and applied to the cheek. Melzack and Wall's gate control hypothesis of pain and descending inhibitory mechanism serve as the sole basis for this particular device.2
Dentistry saw the emergence of the first computer-controlled local anesthetic delivery (CCLAD) device system in the year 1997.3 With this device, a dentist can accurately and precisely supervise the positioning of needle and injection rate. These devices are designed to decrease the drawbacks of conventional Local anesthesia (LA) syringes, such as faster injection rates.
The Woodpecker Star Pen, a new wireless portable local anesthetic delivery device delivers local anesthesia at a controlled speed. Features, such as audio analgesia, auto-aspiration, and three delivery speeds—high, low, and hybrid mode, makes it a modern and innovative method to deliver LA. Being wireless, it allows for freedom of movement, removing and lessening the drawbacks imposed by traditional computer-controlled systems.
Until now, no research has been done to determine the success of Star Pen and Buzzy systems in decreasing pain and apprehension. Therefore, the main purpose of this research was to assess how well Buzzy and Star Pen work to lessen dental apprehension and pain perception in children aged 5–10 while local anesthetic is being deposited.
Materials and Methods
The study was approved by Institutional Ethical Committee (SSDCHIEC/2023/52).
Patient Selection
The main source of samples was children who visited the OPD of Sri Siddhartha Dental College and Hospital's Pedodontics and Preventive Dentistry Department in Tumkur.
The sample of 129 participants who aligned with the inclusion criteria and obtaining consent from parents were selected for the research. The participants were randomly divided into three groups: Group A (n = 43)—conventional needle, group B (n = 43)—Star Pen (Woodpecker), and group C (n = 43) Buzzy (MMJ Labs, Atlanta, Georgia) (Fig. 1).
Fig. 1:
Consort flow diagram
Inclusion Criteria
Participants aged 5–10 years, children who were free of systemic diseases, scored between two and three on Frankl's behavior rating scale, and participants requiring extraction of any primary molar under LA infiltration were included in our study.
Exclusion Criteria
Participants with known allergies to local anesthetic drugs or those with established systemic disease, children who got a definite negative on the Frankl's behavior rating scale, and youngsters below 5 years were excluded from our study.
Randomization
This research study was a randomized controlled trial which uses a simple random sampling technique. Participants were randomly assigned into two groups using a computer-generated table of random numbers. Allocation concealment was performed using the sequencing number opaque sealed envelope technique.
Clinical Procedure and Evaluation Criteria
The patient received a thorough explanation of the process in straightforward language prior to its commencement, with the primary requirement being the administration of local anesthesia.
Following the patient's placement in the dentist chair, a pulse oximeter was positioned on the index finger, and the Animated Visual Pain Rating Scale and Venham's Picture Test (VPT) to gauge the child's limit of anxiety was done in all three groups. In the control group, a standard 2-mL syringe was employed to provide the local anesthetic (Fig. 2). In the Star Pen group, local anesthesia administration was done using the Star Pen at target area (Fig. 3). In the Buzzy group, Buzzy was first placed extraorally above the region or cheek before local anesthesia deposition, following which a standard 2-mL syringe was employed to provide the local anesthetic (Fig. 4). The face, leg, activity, cry, consolability (FLACC) scale was calculated during the procedure in all three groups. Following the procedure, the child's pulse oximeter measurements, Animated Visual Pain Rating Scale, and VPT were implemented to record child's apprehension once more in all three groups.
Fig. 2:
Local anesthesia deposition using conventional needle
Fig. 3:
Local anesthesia deposition using Star Pen
Fig. 4:
Local anesthesia deposition using Buzzy
Following the administration of local anesthesia to each group, standard extraction techniques were carried out.
Results
The mean age of the subjects in the conventional needle, Star Pen, and Buzzy groups was 6.98, 7.54, and 7.07 years, respectively (Table 1). In gender distribution, there were 24 females and 19 males in the conventional needle group; 21 females and 22 males in the Star Pen group; and 20 females and 23 males in the Buzzy group (Table 2).
Table 1:
Age distribution
| Group | Mean | SD | Min–Max |
|---|---|---|---|
| Conventional needle | 6.98 | 1.60 | 5–10 |
| Star Pen | 7.54 | 1.62 | 5–10 |
| Buzzy | 7.07 | 1.50 | 5–10 |
Table 2:
Gender distribution
| Group | Female | Male | |
|---|---|---|---|
| Conventional needle | n | 24 | 19 |
| % | 55.80% | 44.20% | |
| Star Pen | n | 21 | 22 |
| % | 48.80% | 51.20% | |
| Buzzy | n | 20 | 23 |
| % | 46.50% | 53.50% | |
On comparison of pre- and post-VPT score within each group, it was found that in the conventional needle group, the mean post-treatment VPT score was significantly greater than that of the mean pretreatment VPT score (Figs 5 and 6).
Fig. 5:
Animated Visual Pain Rating Scale
Fig. 6:
Comparison of pre- and post-VPT
On comparison of change in pre- and post-Animated Visual Pain Rating Scale within each group, it was found that in the conventional needle group, the mean post-treatment Animated Visual Pain Rating Scale score was significantly greater than that of the mean pretreatment Animated Visual Pain Rating Scale; whereas, in the other two groups (Star Pen and Buzzy), the mean post-treatment Animated Visual Pain Rating Scale score was significantly lower than that of the mean pretreatment Animated Visual Pain Rating Scale score (Fig. 7).
Fig. 7:
Comparison of change in pre- and post-animated Visual Pain Rating Scale
On comparison of change in pre- and postpulse rate within each group, it was found that in the conventional needle group, the mean post-treatment pulse rate was significantly greater than that of the mean pretreatment pulse rate, whereas, in the other two groups (Star Pen and Buzzy), the mean post-treatment pulse rate was significantly lower than that of the mean pretreatment pulse rate (Fig. 8).
Fig. 8:
Comparison of change in pre- and postpulse rate
On comparison of change in pre- and postoxygen saturation, it was found that the mean post-treatment oxygen saturation was significantly lower than that of the mean pretreatment oxygen saturation in conventional group (Fig. 9).
Fig. 9:
Comparison of change in pre- and postoxygen saturation
On intergroup comparison of VPT score, the post-treatment VPT score in the Star Pen group and Buzzy group was significantly lower than that in the conventional needle group (Table 3).
Table 3:
Intergroup comparison of VPT
| Interval | Conventional needle | Star Pen | Buzzy | p-value | |||
|---|---|---|---|---|---|---|---|
| Mean | SD | Mean | SD | Mean | SD | ||
| Pre | 5.30 | 1.26 | 5.42 | 1.24 | 5.61 | 1.05 | 0.386 |
| Post | 6.05a | 0.97 | 3.61b | 1.07 | 3.91b | 1.02 | <0.001* |
*Refers to statistically significant p-value; a,bif there are two different letters between the groups, then it means that the difference between the groups is statistically significant. If two same letters are present between the groups, it means that the difference between the groups is statistically non-significant
On intergroup comparison of pulse rate, the post-treatment pulse rate in the Buzzy group was significantly lower than that in the other two groups (Fig. 10).
Fig. 10:
Intergroup comparison of pulse rate
On intergroup comparison of oxygen saturation, the post-treatment oxygen saturation in the Star Pen and Buzzy groups was significantly lower than that in the conventional needle group (Table 4).
Table 4:
Intergroup comparison of oxygen saturation
| Interval | Conventional needle | Star Pen | Buzzy | p-value | |||
|---|---|---|---|---|---|---|---|
| Mean | SD | Mean | SD | Mean | SD | ||
| Pre | 93.00 | 5.47 | 93.26 | 5.45 | 90.91 | 13.81 | 0.605 |
| Post | 90.21a | 4.22 | 96.37b | 2.87 | 95.26b | 2.97 | <0.001* |
*Refers to statistically significant p-value; a,bif there are two different letters between the groups, then it means that the difference between the groups is statistically significant. If two same letters are present between the groups, it means that the difference between the groups is statistically non-significant
On intergroup comparison of FLACC score between the three groups, it was found that the FLACC score in the Star Pen group was significantly lower than that in the other two groups (Fig. 11).
Fig. 11:
Intergroup comparison of FLACC scale between three groups
Discussion
In pediatric dentistry, administering a local anesthetic that is painless, anxiety free, and comfortable is of prime importance while treating children in a dental clinic. When the treatment is painless, the child becomes cooperative and develops a favorable outlook on dental treatment.4
It is an actuality that pain is a varied, intricate feeling that is affected by a number of psychological or physical elements as a response to unpleasant stimuli. The majority of people experience discomfort and anxiety when local anesthetic is being delivered before dental procedures. This has made dentists to search for more painless methods to deliver local anesthesia and to decrease anxiety levels.
Local anesthesia is the backbone of dentistry, which aims at reducing patient's discomfort and apprehension prior to dental treatment.5 The relationship between a child patient and the clinician may be enhanced by painless LA delivery methods, which could then set the stage for further dental treatments.6
In this research, we used two different methods—Star Pen and Buzzy—to evaluate patient's perceptions of pain and anxiety levels during LA administration. The Woodpecker Star Pen is a cutting-edge wireless portable device which aims to completely transform the way local anesthetic is delivered during pediatric dental procedures. The Star Pen is ergonomic which makes it easier to handle and maneuver during dental procedures since it fits pleasantly in the hand.
With nine changeable injection speeds in the device's three different modes, dentists can customize the injection procedure to cater to the unique requirements of each patient. This level of personalization guarantees the best possible comfort and anesthetic effectiveness, enabling the patient's experience to be more pleasant. In spite of changes in tissue resistance, the Star Pen enables the local anesthetic to be delivered at a precise pressure: volume ratio.7 The related discomfort is decreased since the anesthetic solution is delivered at a measured flow than when contrasted to the traditional syringe. Also, its appearance is more pleasing than the conventional syringe. As a result, the patient receives an injection that is relatively painless and highly efficacious. Even in highly tough tissues, such as the periodontal ligament and palate, it is very safe, pleasing, and controlled injection.
A total of 2% lidocaine hydrochloride and 1:80,000 epinephrine were used in our study's Star Pen device, with a 27G needle and operated in high-speed mode for 45–150 seconds in auto-aspiration mode. As children's cooperation reduces during the longer LA delivery period, the high-speed mode was most suitable for the children. Because of this, the pain and anxiety are lessened, patient behavior is improved, which in turn improves their attitude toward dental care. An evaluation of computer-controlled local anesthetic delivery devices and other alternative CCLAD devices discovered that they are ordinarily more expensive than other methods, which seems to contradict the device's effectiveness.
Melzack and Wall's gate control concept of pain (1965)2 and descending inhibitory mechanism serve as the basis for the functioning of the Buzzy device. According to the gate control theory, a modulating center in the spinal cord's dorsal horn is responsible for sending pain signals from the peripheral nervous system (PNS) to the central nervous system (CNS). Pain perception can be brought down by innervating nerves that pass on non-noxious stimuli. Unmyelinated A-delta and C fibers transmit pain at a rate of 0.5–2 m/seconds and 6–30 m/seconds, respectively, while myelinated A-beta fibers transmit vibration stimuli at a rate of 30–70 m/seconds.8,9 In addition to this, vibrating stimuli activate mechanoreceptors in the skin, underlying bone, and subcutaneous tissue which include Pacinian and Meissner's corpuscles.10
Vasoconstrictors, which are present in local anesthetics, are employed to narrow blood vessels, to counter the anesthetic's vasodilatory effects, extend its duration, lessen toxicity and systemic absorption, and provide a bloodless operating field. Children are advised not to take more than 4.4 mg/kg body weight of lidocaine and mepivacaine in the absence of vasoconstrictors, and 7 mg/kg body weight of lidocaine in the existence of vasoconstrictors. In the current clinical trial, the local anesthetic was used in proper dosages and as an essential part of the treatment for child's oral health.5
The VPT and animated visual pain assessment scale were employed to assess the extent of discomfort perceived during the deposition of LA. VPTs were compared between the groups, and it was found that Buzzy and Star Pen had significantly lesser post treatment VPT scores than the standard needle group. On intergroup comparison of Animated Visual Pain Rating scale, the conventional needle group's post-treatment animated emoji scores were significantly increased than the other two groups, while Star Pen group's score was significantly lower.
The Buzzy group had comparatively lower post-treatment pulse rates, while Star Pen had lower FLACC scores. All the three group's O2 saturation extent failed to vary significantly; however, the Star Pen and Buzzy groups had higher levels after treatment. The harm to tissue that results from actual mucosal perforation and the pressure created by infiltration are the potential causes as to the cause people experience pain when a local anesthetic is delivered. Hence, a useful alternative for conventional injection systems would be to discover methods for providing anesthetic for dental treatments so as to provide a painless dental treatment and cause less anxiety.
The drawbacks of using Star Pen and Buzzy systems are related to their high costs and the longer duration necessary to inject the local anesthetic solution on an average of 60–120 seconds.
Sinnarkar et al. conducted a research, where they explored and evaluated the advantage of cooling, extraoral and intraoral vibrations in decreasing discomfort experienced during inferior alveolar nerve block (IANB) administration. On comparing with vibratory stimuli alone, a high vibratory device with coolant was a potent technique in pedodontics and a promising substitute for lowering affliction and anxiousness in kids undergoing IANB.7
The Buzzy device, a potential behavior-guiding tool for minimizing dental apprehension and pain, aids in distracting children undergoing LA treatments. The Buzzy device may be employed as supplementary in pediatric dentistry, which is more accessible, optimized, and economical than recently implemented LA devices.11
Aligning with our research, in an investigation by Fatma et al., who exhibited a randomized clinical trial to assess the potency of topical anesthetic, precooling and Buzzy devices in reducing discomfort during needle related dental procedures.12 Anxiety levels pre- and postinjection were evaluated using the Wong–Baker Faces Pain Rating Scale (WBFPRS). Heart rates and oxygen saturation were noted prior to, during, and after the needle injection using a pulse oximeter. Sound-eye-motor value was evaluated throughout the process. It was deduced that implementation of external cold and vibration are useful methods to reduce discomfort during buccal infiltration anesthesia.
Based on research on other CCLAD devices, youngsters who underwent local anesthesia procedure using Star Pen device were less likely to be restless, show disruptive body movements, or required physical restraint.
In a randomized control trial by Patel et al.,3 they attempted to examine how well the Star Pen device assessed pain perception and found that it was highly efficient in lowering children's dental anxiety.
One unique feature of Star Pen is its smaller head, which aids in the accurate application of the local anesthetic solution, and its comfortable pen grasp. However, while administering buccal infiltration to children, the Wand computerized system and traditional syringe did not vary in terms of administering of LA in line to a research exhibited by Kandiah and Tahmassebi. This may be attributed to the fact that youngsters who took part in the clinical study may have been unable to accurately and conclusively determine their anxiety levels.13
Theoretically, computer-assisted local anesthesia delivery methods reduce pain during the needle injection process by introducing a local anesthetic solution in front of the needle course by the use of continuous positive pressure.7 It is possible that this prepuncture method added to the perceived decrease in discomfort.12 For youngsters who may have the need of dental care, the Star Pen technology has the ability to generate a positive, pain-free, and stress-free dental experience.13 However, more thorough investigation of pulp therapy treatments using this device is required to completely estimate the device's best uses and capabilities.
The limitations of the present study are, that the effectiveness of the Star Pen in anesthetizing teeth that require pulp therapy was not assessed in this study since it only examined teeth that needed anesthesia for extractions utilizing the Buzzy and Star Pen system. Furthermore, because the operator in this trial was constantly aware of the LA administration strategy, blinding was not achievable.
Conclusion
It is well recognized that fear is a primary factor in youngsters delaying and avoiding dental care. This phobia is more frequently linked to needle and injection-related anxiety. The appearance of needles and the loss of control over speed when administering local anesthesia are problems with traditional injection procedures.
Within the limitations of our investigation, it can be inferred that Star Pen and Buzzy systems can be used as effective local anesthesia delivery methods to alleviate needle associated pain and anxiety in children aged between 5 and 10 years.
Both the methods can be used as valuable adjuncts in pediatric dentistry and can be used as novel devices to deliver local anesthesia when compared to conventional needle. They can be used to improve behavior management and improve patient compliance.
Orcid
Jyothsna V Setty https://orcid.org/0000-0001-7346-7849
Nikhitha Elsa Shaji https://orcid.org/0009-0001-4022-3407
Rajashekar Reddy Vundela https://orcid.org/0000-0002-0209-6646
Mahesh Kumar Karuppiah https://orcid.org/0000-0003-1326-8121
Footnotes
Source of support: Nil
Conflict of interest: None
References
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