Traditional face-to-face versus distance learning of local anesthesia injection technique by novice learners

Abstract

Background

Local anesthesia is an essential skill of pain control for most dental procedures, commonly taught through face-to-face learning (FFL). Distant learning (DL) has emerged as an alternative teaching method for many techniques in medicine.

Aim

To evaluate the performance scores of DL compared with FFL in teaching maxillary infiltrative local anesthesia to novice learners.

Methods

A prospective randomized trial included 93 students randomized into two groups for applying infiltrative local anesthesia of the maxillary arch: FFL (n = 47) and DL (n = 46). The evaluation was conducted by two examiners using a performance checklist and a global rating tool. Agreement between the examiners was calculated, and performance scores of the participants on 11 well defined tasks in the process of infiltration were compared. Participants’ satisfaction was assessed via a questionnaire.

Results

Levels of completion of each infiltration step were not statistically significantly different between the learning groups (p > 0.05). Group differences in the duration of the total infiltration procedure (76.06 ± 20.36, and 83.39 ± 24.05 s, for the FFL and DL groups, respectively) also were not statistically significantly different (p = 0.116). Both methods were reported as efficient by participants. While nearly all students enjoyed the learning process in both groups, all FFL participants felt confident performing the infiltration and 11% less confident in the DL group.

Conclusion

The results suggest that distant learning of administering infiltration local anesthesia was as effective as in-person learning by novice learners. Students appreciated the respective method of learning, with more reservations to perform the procedure by those in the DL group.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12909-026-08962-w.

Introduction

The administration of local anesthesia is a fundamental aspect of dental education, and an essential prerequisite step for pain management prior to most procedures in daily general dental practice. It is among the most frequently performed pre-procedures in dentistry with an estimated 300 million cartridges consumed annually in the US and over 2 million injections given daily on a global scale [1, 2] Moreover, patients are reported to select their dentist based on the dentist’s ability to deliver pain-free therapy that facilitates treatment [3, 4].

Local anesthesia training integrates theoretical knowledge with practical application of peripheral nerve block techniques conducted on fellow students or through specialized simulation models involving direct face-to-face supervision by part-task trainers to enable learners achieve technical competency. Dental schools increasingly incorporate model training into anesthesia courses to prepare students before initial in-vivo injections [5]. Local anesthesia is also a core competency for special certification of dental hygienists and therapists across Europe and the US.

A global trend to utilize distance learning in various disciplines is supported by advances in web-based technologies to provide more reliable, equitable, efficient and cost-effective education [6]. Remote education reportedly enhances individual accessibility particularly in rural or lower socioeconomic areas, eases faculty workloads, and improves costs for educational institutions [7, 8].These advantages were magnified during the unprecedented disruption to education systems by the COVID-19 pandemic (2020) [9]. The integration of online education in the medical curriculum eventually complemented or supplemented the traditional face-to-face education [10, 11]. This development led to increased research on the effectiveness of distance learning compared to traditional learning in health education.

Most studies are survey-based and focus on the perceptions and attitudes of learners and students rather than objective outcome measures [12]. Previous comparisons on the administration of anesthesia were based on questionnaires targeting the participants’ ease of manipulation and comfort during the procedure [13, 14]. However, this intervention includes various steps that should be gauged separately in a more encompassing study. Accordingly, we aimed to investigate differences in face-to-face and distance learning methods spanning these procedural steps in a novice student cohort. We hypothesized that through a-step-by-step instruction of the method, DL and FFL should not yield different instructional outcomes.

Materials and methods

This study is a prospective randomized trial for teaching the infiltration of local anesthetic injection technique in the maxillary arch. A total of 93 participants were enrolled, equally divided between a group receiving traditional face-to-face learning (FFL; n = 47, 50.53%) and another taught through distance learning (DL; n = 46, 49.46%) (Table 1). Sample size was calculated with a power of 90% at a permissible (α) error of 0.05 based on previously published studies. Accordingly, 92 participants were required. Of a total pool of around 500 students invited to participate in the study, 93 volunteers were recruited.

Table 1.

Participant baseline characteristics

Total Number of Participants N = 93
	Face to Face Learning n  = 47 (50.53%)	Distance Learning n  = 46 (49.46%)	p-value
Age	19.77 ± 1.735	19.17 ± 1.305	0.066
Gender
Male	12(25.5%)	18(39.1%)	0.161
Females	35(74.5%)	28(60.9%)
Category
Pre-Med	28(59.6%)	26(56.5%)	0.505
Med I	4(8.5%)	1(2.2%)
Med II	3(6.4%)	4(8.7%)
Nursing	12(25.5%)	15(32.6%)
Hand Dominance
Left	6(12.8%)	7(15.2%)	0.733
Right	41(87.2%)	39(84.8%)
Plays a musical instrument
Yes	12(25.5%)	9(19.6%)	0.491
Musical Instrument
Piano	6(12.8%)	5(10.9%)	0.755
Guitar	2(4.3%)	2(4.3%)
Flute	0	1(2.2%)
Violin	1(2.1%)	0(0%)
I have enrolled in a distance-learning course before enrolling in this study
Yes	25(53.2%)	33(71.7%)	0.065
No	22(46.8%)	13(28.3%)

The participants were students in pre-medical senior biology, medical laboratory, and nutrition students; first- and second-year medical students from a four-year Doctor of Medicine graduate-entry program; and nursing students. Most participants were pre-medical students (Table 1). The mean ages were 19.77 ± 1.735 years and 19.17 ± 1.305 years (p = 0.066) in the FFL and DL groups, respectively, with higher proportion of females in both groups (74.5% and 60.9%; p = 0.161). Excluded were students who had previous experience in administering local anesthesia and those who had local anesthesia in their scholarly curriculum.

The research was approved by the institutional review board (SBS-2022-0117); equal opportunity was provided to all volunteers who then signed the pertinent consent. Randomization was computer-generated. Participants were notified by email about the date of their session. Their identification number was provided on the day of the session.

Study design

Learning method

The local anesthetic was administered in the maxillary first premolar region of a typodont mounted within a phantom head, targeting the area of the middle superior alveolar nerve. The simulated injection was performed into silicone layers designed to simulate mucosa. A full-time faculty member in the department of Dentofacial Medicine with more than ten years of experience in clinical teaching of dental trainees conducted all teaching sessions in both groups over a period of nearly 6 months. The instructional steps differed between groups:

FFL group: traditional face-to-face hands-on teaching of local anesthesia administration

This instruction included viewing a 12-minute video with real-time instructor commentary. After a replay of the video the method was demonstrated in-person on a typodont. The students practiced the injection under direct supervision, receiving immediate feedback until satisfactory performance was achieved.

DL group: distance learning technique in teaching local anesthesia administration

The instruction was delivered via a web-based virtual classroom (Webex/Zoom) without face-to-face interaction. Students viewed the same 12-minute video with live instructor commentary, then a replay, followed by live online demonstration of the injection technique by the instructor with the camera turned on. Students practiced independently and periodically activated their cameras to receive instructor feedback until satisfactory performance was achieved.

The video’s content had been thoroughly reviewed and validated by our research team to ensure reliability. The participants in both groups were not given the link of the instructional video prior to attending the sessions. Each learning session included an average of five students and one instructor. To avoid poor internet connectivity issues, the remote sessions were run on our reliable university hospital premises; the participants used personal headsets and their own computers/smartphones. The students were provided with the following materials: syringe, needle tip (27 gauge), anesthesia cartridge (2% Lidocaine, 1:100,000 epinephrine), typodont with silicone layer incorporated within a phantom head.

Data collection and outcome measurement

Participant demographics were obtained using a questionnaire on age, gender, dominant hand, and prior experience of playing musical instruments. The questionnaire utilized was specifically developed for the purposes of this research (provided as supplementary file). Immediately following the instructional session, students were instructed to administer the local anesthetic. The duration of the procedure was limited to a maximum of 10 min. Each student’s performance was videotaped. Video recordings were muted and deidentified; only the typodont and the student’s gloved hands were included in the video frame. The time interval between the educational sessions and the application of the video-taped procedure was standardized within 5 to 10 min.

Two independent dentists with extensive teaching and practice experience who did not contribute to teaching and video recording evaluated the video-recordings assessed each video using two validated checklists corresponding to different sets of variables. To eliminate any potential bias, the examiners were blinded to the participants’ instructional groups.

The examiners scored 11 procedural steps according to a detailed checklist (Table 2). They also scored a specially designed Objective Structured Assessment of Technical Skills (OSATS) scoring system (range 1, low to 5, high) sheet to determine the effectiveness of distant learning compared to traditional face to face learning methods (Table 3). A grading system was used to evaluate the adequate handling of instruments and the correct injection of the anesthetic in the tissues (Appendix 1). Student performance was evaluated via an additional checklist for assessing the injection method among medical students (Appendix 2). The checklist scores were calculated based on a formula used by the same authors [15]: “cutoff time (seconds) – completion time (seconds) – (10 x sum of errors). For each assessment by both examiners, the average rating per each graded checklist item, OSATS total score, and the checklist formula was used in the statistical analysis.

Table 2.

Performance in procedural steps by participants in the face-to-face (FFL) versus distance (DL) learning groups

	Checklist item	FFL N = 47	DL N = 46	p-value
1	Properly inserts the anesthesia cartridge in the syringe	42 (89.4%)	44 (95.7%)	0.226
2	Properly mount the needle on the syringe	46 (97.9%)	43 (93.5%)	0.175
3	Properly hold the syringe	43 (91.5%)	43 (93.5%)	1.000
4	Uncap the needle	46 (97.9%)	46 (100%)	1.000
5	Test the syringe for air bubbles before injection	38 (80.9%)	29 (63%)	0.146
6	Properly orients the needle upon insertion (bevel faces bone)	42 (89.4%)	42 ( 91.3%)	1.000
7	Properly inserts the needle in the apical region of teeth	42 (89.4%)	32 (69.6%)	0.060
8	Aspirates before the administration of anesthesia	28 (59.6%)	25 (54.3%)	0.388
9	Slowly inject the anesthetic solution	44 (93.6%)	38 (82.6%)	0.069
10	Slowly withdraw the syringe	46 (97.9%)	43 (93.5%)	0.361
11	Recap the needle safely	40 (85.1%)	36 (78.3%)	0.101

Chi square test of independence

Table 3.

Checklist formula score and OSATS total score (mean ± SD) in face-to face (FFL) and distance (DL) learning groups

	FFL	DL	p-value
Checklist formula score	514.26 ± 22.031	502.80 ± 28.113	0.031
OSATS total score per student	28.66 ± 3.480	27.66 ± 4.203	0.216

t-test

The students were asked, on a voluntary basis, to complete a questionnaire structured with clear self-explanatory language, avoiding negatively phrased items. The questions addressed demographics (age and sex), past DL learning experience and future interest in surgical specialty (Yes and No answers), and course enjoyment and confidence performing the procedure on a 7-point Likert-scale. In addition, three open-ended questions were included for more comprehensive understanding of the students’ perceptions (Appendix 3).

The OSATS global rating scoring sheet and the performance checklist are validated tools published in previous studies [15–17]. The questionnaire was tailored to provide information from the study’s participants and did not require independent validation.

Differences between groups (DL vs. FFL) and variables (check-list time) were evaluated with independent t-test. Chi square tests were employed to determine differences between examiners 1 and 2 (OSATS) and the performance in procedural steps by participants in the learning groups. Cohen’s kappa coefficient was calculated to assess inter-rater reliability, factoring in the prevalence of raters’ agreement.

Results

Most participants were right-handed, with no statistically significant difference between the groups (p = 0.733, Table 1). Fewer students played musical instruments (25.5% and 19.6% in the FFL and DL groups; p = 0.491), most commonly the piano (12.8% and 15.2%). Previous experience with distance learning was reported by a higher percentage in the DL group (71.7%) than in the FFL group (53.2%) but the difference was not statistically significant (p = 0.065) (Table 1). Time duration to complete the procedure was nearly equal in both groups (FFL: 76.06 ± 20.358 s, DL: 83.39 ± 24.048 s and the difference not statistically significant (p = 0.116).

High performance (over 80%) was observed in most tasks across both groups, and the differences were not statistically significant (Table 2). Notable exceptions were the lower scores (less than 60%) in both groups for aspiration before anesthetic administration. The participants in the FFL group slightly surpassed the DL learners on the checklist formula scores (514.26 ± 22.031 and 502.80 ± 28.113, respectively; p = 0.031) (Table 3). The OSATS total scores between the two groups were nearly equal and the differences not statistically significant.

The success rates varied among the 11 steps of the injection procedure and were judged similarly between examiners 1 and 2 with no statistically significant differences except for properly orienting the needle upon insertion with the bevel facing the alveolar bone (90.3% by examiner 1, 98.9% by examiner 2; p = 0.023; Fig. 1). The lowest grading (< 80%) related to aspiration before the administration of anesthesia and testing the syringe for bubbles before injection. The overall procedural skill score was higher by Examiner I (9.98 ± 1.61) compared to Examiner II (9.53 ± 1.364, p = 0.016); the sum of errors was lower for Examiner I (1.02 + 1.161) than Examiner 2 (1.32 + 1.295; p = 0.048). The minimum and maximum scores were 0 and 6, respectively, for both examiners.

Fig. 1.

Comparison of satisfactory grading (percentage of total participants n = 93) by examiners 1 and 2 of the 11 steps of the administration of local anesthesia. All comparisons were not statistically significant except for #6* (“properly orients the needle upon insertion”) (p = 0.023), indicating close correspondence between the examiners

Most OSATS assessments by the two examiners were high, with scores of 4 and 5 and were not statistically significantly different, including the total scores per student, except for the “safety” assessment (p < 0.0001). Accordingly, the OSATS assessments were grouped as low (scores 1 and 2), average (3), and high (4 and 5) and the data on differences between examiners and agreement computed accordingly (Table 4). Inter-rater reliability was highest for direct injection steps (0.677 < 0.796: aspiration, injection, air bubble testing, and needle recapping) except for needle insertion in the designated anatomical region (K = 0.411) and lower for the other steps (-0.0016 < K < 0.389), mainly cartridge insertion and speed of syringe withdrawal. Uncapping the needle had the highest perfect correspondence (K = 1) (Table 5).

Table 4.

Comparison of OSATS ratings between examiners*

		Examiner I N = 93	Examiner II N = 93	P value
Respect for tissues	1–2	1(1.1%)	3(3.2%)	0.283
	3	8(8.6%)	13(14%)
	4–5	84(90.3%)	77(82.8%)
Time and Motion	1–2	2(2.2%)	3(3.2%)	0.224
	3	17(18.3%)	22(23.7)
	4–5	74(79.6%)	68(73.1%)
Instrument Handling	1–2	6(6.5%)	6(6.5%)	0.186
	3	23(24.7%)	26(28.0%)
	4–5	64(68.8%)	61(65.6%)
Injection Technique	1–2	5(5.4%)	3	0.448
	3	12(12.9%)	22(23.7)
	4–5	76(81.7%)	68(73.1%)
Safety	1–2	7(7.5%)	5(5.4%)	0.646
	3	15(16.1%)	14(15.1%)
	4–5	71(76.3%)	74(79.6%)
Flow of Operation	1–2	2(2.2%)	8(8.6%)	0.296
	3	20(21.5%)	19(20.4%)
	4–5	71(76.3%)	66(71%)
Knowledge of Procedure	1–2	1(1.1%)	0	0.266
	3	21(22.6%)	30(32.3%)
	4–5	71(76.3%)	63(67.7%)
Total Score per student**		27.94 ± 4.056	28.40 ± 4.709	0.476

*chi square test of independence

**t-test

Table 5.

Inter-rater Reliability – Procedural Checklist

Item	Cohen’s κ	95% CI
Properly insert the anesthetic cartridge in syringe	−0.038	−0.067 to − 0.009
Properly mount the needle on the syringe	0.389	−0.150 to 0.928
Properly hold the syringe	0.225	−0.171 to 0.621
Test the syringe for air bubbles before injection	0.693	0.517 to 0.869
Properly orients the needle upon insertion	0.184	−0.128 to 0.496
Properly inserts the needle in the apical region of teeth	0.411	0.158 to 0.664
Aspirates before administration of anesthesia	0.773	0.642 to 0.904
Slowly inject the anesthetic solution	0.677	0.414 to 0.940
Slowly withdraw the syringe	−0.016	−0.041 to 0.009
Recap the needle safely	0.796	0.624 to 0.968

Uncap the Needle correspondence = 1

Most participants expressed confidence in their performance, slightly more in the FFL group (22%) than the DL group (19%) (Fig. 2). Over 40% reported strong overall interest in pursuing oral surgery in both learning modalities (Fig. 3). Nearly all students related enjoyment in the course, also with slightly greater rate in the FFL group (Fig. 4). Participants greatly appreciated the practical hands-on approach of the course, the opportunity for repeated practice, the interactive teaching format, and the clarity of procedural instruction. A frequently mentioned strength was the early exposure to a clinical skill. In contrast, some students found the remote or online format of the session limiting. Several respondents expressed strong preference for face-to-face demonstrations, suggesting that certain practical details, mainly the needle manipulation and angulation and needle handling were harder to grasp virtually.

Fig. 2.

Responses of participants to the question: “I feel comfortable performing local anesthesia”

Fig. 3.

Responses of participants to the question “I am interested in oral surgery as a potential specialty in the future.”

Fig. 4.

Responses of participants to the question “I found this course enjoyable.”

Discussion

The results of this study provide valuable insights into procedural skill acquisition and evaluation. Performance across all eleven levels of anesthetic infiltration, along with the duration of the total procedure were not statistically significantly different between the FFL and DL groups. These findings suggest that both distance and face-to-face learning are effective in instructing novice learners the clinical process of local anesthesia administration. However, responses to the post-instruction questionnaire and the accompanying individual narrative tend to favor face-to-face instructions. While most students enjoyed the learning process in both groups, confidence levels performing the infiltration differed: all FFL participants felt confident and 11% in the DL group felt less confident.

Performance in both FFL and DL groups on the checklist items exceeded 80% on most items except in the needle aspiration task before injection (less than 60% - Table 2). This finding suggests that the students in both groups did not properly learn the procedure and possibly that the instructors did not adequately emphasize this step.

Examiners’ evaluations were greatly concordant except on properly orienting the needle upon insertion with the bevel facing the alveolar bone (Fig. 1). However, both examiners had ratings greater than 90% on this item (90.3% by examiner 1, 98.9% by examiner 2), despite the clinical significance. Clinically more relevant, though not statistically significant, were the examiners’ grading of testing the syringe for air bubbles before injection (79.6% by examiner 1, 75.3% by examiner 2), and aspiration before the administration of anesthesia (66.7% by examiner 1 and 58.1% by examiner 2). Both steps relate to needle control independent of the injection act that were omitted or improperly performed by the students. One examiner consistently assigned higher scores than the other for 10 of the 11 steps. Both examiners rated performances at high levels, with a prevailing score of 4 and 5, respectively. These findings underscore the potential for distance learning to achieve comparable outcomes with proper implementation and evaluation standards. This tenet is further reinforced by the finding that both modalities required nearly the same time duration to complete the procedure with a slight average outperformance in the FFL group. However, findings of no statistically significant differences may not be equated with equal effectiveness, particularly considering written statements by many participants favoring in-person instruction, and the research limitations detailed below.

The results of this study align with existing research findings on the efficacy of online video-based teaching, on basic and advanced surgical skills (including laparoscopic and robotic skills) [10, 11, 17]. As such, local anesthesia administration may be considered a basic surgical act. Specifically, online teaching was found to result in significant knowledge gain [6, 12, 18–20], rapid skill progression [21], and high student satisfaction [12]. Moreover, distance learning approaches of practical skills, incorporating video technology and virtual animations, was found feasible and acceptable by undergraduate dental students [22], effective in acquiring endoscopic sinus surgical skills in novices [23] and double-handed knot tying, and comparable to traditional face-to-face methods [24]. However, shortcomings of these studies included limited sample sizes [23, 25], lack of control group [23], the use of non-validated tools for measuring outcomes [23, 25], and lack of baseline assessment. Accordingly, distance learning should be considered as a complement to direct clinical supervision and not as a standalone replacement.

Performance assessment was conducted immediately following the instructional session, capturing only short-term skill acquisition rather than long-term retention for clinical applicability. A person usually retains 10% to 15% of read content, 10% to 20% of heard content, 20% to 30% of what is seen [26], and 40% to 50% of combined audio and visual presentations. Research on various practical applications is needed.

Although the use of typodonts and silicone layers provided a controlled simulation environment, the findings might not be generalized as they do not necessarily apply to real-life dental work with variable procedural complexity. Additionally, despite efforts to ensure consistency, the distance learning group may have been affected by certain technical differences including device limitations such as sound and camera clarity. Finally, from a research perspective, further study should focus on whether repetitive sessions in both modalities would narrow the reported gaps. Also, the research addressed a dental procedure, but the participants were not dental students, thus not as exposed to oral anatomy and tactile practice, and the results might differ with a strict dental cohort in whom presumably more educational information would be sought. However, if included, dental students would have been fresh in school, equally labeled as novice participants. Nevertheless, the participants were students in health domains with a familiar medical-dental background.

Considering the normalization of online education stemming from the covid-19 era, the DL method remains a helpful adjunct to medical and dental curricula that serves the student when deemed applicable by curricular decision makers. Validated online delivery may vary depending on institutional standards and applicability, class size, teacher to student ratios, and remote campuses. Hybrid methods are common taking into consideration these variables. The results of DL could be enhanced in different ways, such as adding in the initial trial voiced instructions at each step, or having in the DL group, after the instructions, one or more students perform the procedure with all other participants attending and submitting criticism of the performance and means to correct deviations.

Conclusion

The findings of this study validate distance learning as an educational tool. Overall procedural competence, as assessed by OSATS, did not differ significantly between learning modalities. However, face-to-face learning was more advantageous in nearly half of checklist-based procedural skills for individual items and was favored in individual testimonies by participants as providing higher confidence with direct supervision. Considering that local anesthesia injection is a basic surgical act preceding dental and surgical procedures that require supervision on real patients, the online experience should be regarded as an adjunct to in person learning.

Authors’ contributions

Conceptualization: A.Z, K.ZMethodology: A.Z, K.Z, J.HData Collection: J.H, F.N, E.BStudy analysis and investigation: J.H, K.Z, F.N, E.H, M.A, E.BWriting, review and editing the manuscript: All authors. All authors approved the final version of the manuscript.

Funding

The current study did not receive any funding to the conceptualization, design, data collection, analysis, decision to publish, or preparation of this manuscript.

Data availability

All data generated or analyzed during this study are included in this published article.

Declarations

Ethics approval and consent to participate

This study was conducted in accordance with the ethical principles of the Declaration of Helsinki (World Medical Association) and was reviewed and approved by the AUBMC Institutional Review Board – AUBMC IRB - SBS-2022-0117. All participants provided written informed consent prior to participation.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.