Evaluation of dental treatments under nitrous oxide-oxygen inhalation sedation in pediatric patients with dental anxiety: a 10-Year retrospective study

Abstract

Background

This study assessed the use of nitrous oxide-oxygen (N₂O-O₂) inhalation sedation in pediatric dental treatments, focusing on patient demographics, general health status, and the types of procedures performed.

Methods

This retrospective study analyzed clinical records of 96 pediatric patients (aged 4–12 years) treated at the Pediatric Dentistry Clinic, Ege University, School of Dentistry, under N₂O-O₂ inhalation sedation between 2010 and 2020. The study statistically examined archival data to analyze patient demographics, health status, adverse effects. success rates, and dental procedures performed.

Results

In 96 pediatric patients (33 girls, 63 boys) with dental anxiety, 128 sedation applications were performed to conduct 162 dental treatments. The participants were categorized as ASA I and ASA II based on their overall health condition, and their ages spanned from 4 to 12 years. The patients treated under N₂O-O₂ inhalation sedation underwent 52 restorative fillings, 1 vital pulp treatment, 4 endodontic treatments, 103 tooth extractions, 1 impression for space maintainer, and 1 gingival surgery. None of the 128 sedation procedures resulted in reported adverse effects.

Conclusion

Dental treatments under N₂O-O₂ inhalation sedation in pediatric dentistry are a safe method used for patients with dental anxiety. These procedures can facilitate the provision of appropriate treatments for uncooperative patients, ultimately leading to improved quality of life.

Background

Fear can be characterized as a natural emotional response stemming from the perception of a genuine threat, whereas anxiety is linked to fearful reactions towards an anticipated, but unrealistic, threat situation. Dental anxiety refers to intense apprehension about dental procedures, even in the absence of a clear cause [1]. Dental fear and anxiety are complex phenomena affected by many variables [2]. The dental anxiety exhibited by children can arise from various factors, including socio-cultural elements originating from parents or the environment, the child’s negative experiences with dentists, and the dentist’s lack of expertise or inexperience in handling pediatric patients [3]. The noise of dental handpieces, the smell of dental materials, pain during treatment, or fear of local anesthesia may trigger dental anxiety [4].

Dental anxiety is a significant global concern, particularly among children [5]. While psychological behavior management techniques are often effective, some cases require pharmacological interventions [6]. Pharmacological treatments such as general anesthesia and sedation methods are the only solutions that can be applied if a dentist cannot manage the child’s anxiety with behavioral management. Sedation, a pharmacological behavioral guidance technique, can be a treatment option for young children [7].

In sedation, pharmacological agents are administered in various ways and combinations, including oral, intravenous, inhalation (transmucosal), rectal, and intramuscular routes. According to the patient’s needs and indications, different doses of pharmacological agents can be used, and it is possible to obtain anesthesia ranging from minimal sedation to general anesthesia [8]. Sedation facilitates the management of dental treatment and minimizes the level of dental fear in children. Therefore, the occurrence of dental fear and anxiety can be prevented by eliminating unfavorable dental treatment history [8]. In addition, sedation simplifies the accomplishment of dental procedures for the dentist and helps to decrease the tension of patient. The child should respond to verbal and physical stimulations under conscious sedation [9]. Consciousness depressed minimally, open airways, and protective reflexes should be maintained. N₂O-O₂ inhalation conscious sedation should be preferred as a priority as a pharmacological behavior management method for dental treatment of American Society of Anesthesiologists (ASA) Physical Status I and II children with anxiety [9]. According to the ASA Physical Status Classification System, ASA I defined as normal healthy patient with normal body mass index percentile for age, ASA II is defined as patient with mild systemic disease (e.g., mild obstructive sleep apnea or mild asthma), ASA III, patients with severe systemic disease(e.g. Renal failure, muscular dystrophia), ASA IV is defined to a patient with severe systemic disease that is a constant threat to life (e.g. Symptomatic congenital cardiac abnormality, congestive heart failure), ASA V is defined to a moribund patient who is not expected to survive without the operation (e.g. Massive trauma, intracranial hemorrhage with mass effect, patient requiring ECMO) and at the end ASA VI is defined a declared brain-dead patient whose organs are being removed for donor purposes.

Nitrous oxide is a sedative gas with analgesic and muscle relaxant properties. It is non-irritant to the respiratory tract and has low solubility, allowing for rapid onset and recovery compared to general anesthetic agents [10]. Recent evidence from studies published refined dental sedation techniques to improve patient comfort and procedural success. Systematic reviews have consistently demonstrated that moderate sedation using agents such as midazolam—often in combination with nitrous oxide—effectively reduces dental anxiety while maintaining a favorable safety profile [11]. For example, a 2017 meta-analysis highlighted midazolam as the most commonly used sedative in dental procedures, with its predictable pharmacokinetics contributing to both rapid onset and smooth recovery [11]. Additionally, evolving protocols in conscious sedation now emphasize personalized dosing and careful patient monitoring, which are essential for tailoring sedation depth to individual needs and minimizing complications [12]. More recent meta-analyses have expanded on these findings by comparing different sedative regimens and routes of administration. A 2020 meta-analysis on third molar extractions found that conscious sedation not only alleviates anxiety but also enhances overall patient and operator satisfaction, despite some variability in outcome measures [12]. Complementary evidence from a 2021 review further confirmed that oral sedation using benzodiazepines reliably reduces perioperative anxiety during dental procedures and stressed the need for standardized outcome assessments to optimize sedation protocols [13]. Together, these studies underscore the importance of evidence-based sedation practices in modern dentistry to ensure safe, effective, and patient-centered care. Although multiple studies [7, 14, 15] have compared the effectiveness of drug combinations, there are very few studies reporting outcomes of N₂O-O₂ inhalation sedation alone in pediatric dentistry [16]. This study aims to evaluate the demographic characteristics, dental procedure types, sedation durations, adverse effects and success rate of pediatric dental treatments performed under N₂O-O₂ inhalation sedation over a ten-year period.

Methods

This study was conducted through a retrospective examination of the clinical records of 96 pediatric patients, who were examined and treated at the Pediatric Dentistry Clinic of Ege University, Faculty of Dentistry, and whose treatments were completed under the N₂O-O₂ inhalation sedation with titration method. During the examination, the patients were evaluated intraorally, extraoral, physically, systemically, and mentally, and the decision was made to perform their treatments under sedation. The present retrospective study was conducted in full accordance with the World Medical Association Declaration of Helsinki. Before data collection, ethical approval was obtained from Ege University, Faculty of Medicine Non-intervention Clinical Research Ethical Committee (dated February 24, 2022 protocol number: 22-2.1T/36). As part of the inclusion criteria, only patients classified as ASA I or ASA II were included. All eligible records were included. The study patients who exhibited uncooperative behavior and could not be managed through basic behavior guidance techniques during examination or treatment due to dental anxiety were excluded from the list. Informed consent for the publication was obtained through face-to-face or telephone interviews with patients’ legal representatives. Archival data were accessed only after approval. All personal identifiers were removed and data were anonymized before analysis to ensure confidentiality and compliance with the Declaration of Helsinki.

Collected data listed in categories of demographic (age and gender), general health condition (ASA score), sedation data (time, success status, and adverse effect), and data of dental treatment (extraction, restorative and/or endodontic procedure). Success was defined as completing the planned procedure under N₂O-O₂ inhalation sedation alone, without the need for any additional sedative or anxiolytic agent. Cases in which treatment was aborted or supplementary sedation was required were classified as failures.

Dental treatments performed under N₂O-O₂ inhalation sedation are grouped as follows:

1. Restorative treatment

2. Vital pulp treatment

3. Endodontic treatment

4. Tooth extraction

5. Space maintainer

6. Gingival surgery

The N₂O-O₂ inhalation sedation procedure was uniformly applied with Quantiflex MDM (USA, Ohio, Fraser Sweatman) to all patients and was conducted as follows. As the pre-sedation preparation, the process begins with a thorough patient evaluation that includes reviewing medical and dental histories, assessing baseline vital signs (blood pressure, heart rate, oxygen saturation), and confirming that no contraindications exist. The dentist explains the procedure to the patient and obtains informed consent. Meanwhile, the sedation unit is checked for proper function, ensuring the oxygen and nitrous oxide cylinders are secure and that the scavenging system is operational. The patient is then seated comfortably in the dental chair, and a well‐fitting nasal mask is placed to ensure an effective seal.

As a process of administration, maintenance, and recovery, initially, 100% oxygen is administered, at the beginning for 3 min to pre-oxygenate the patient. Subsequently, N₂O–O₂ concentration was initially set at 30% N₂O for all patients, and while continuously monitoring patient’s responses and vital signs, was gradually titrated upward by 5–10% points every five minutes to achieve the desired level of sedation, typically ranging from 30 to 50% nitrous oxide. During the dental procedure, the sedation level is adjusted as needed to keep the patient relaxed yet responsive. Upon completion of the treatment, the administration of nitrous oxide is discontinued, and 100% oxygen is delivered for 5 min to eliminate any residual nitrous oxide, facilitating a smooth recovery. The patient is then monitored until full alertness is regained, and post-procedural instructions are provided before discharge. For the statistical analysis, Descriptive statistics (mean and percentage) were presented in this study. When the sample size assumptions were not met, the Fisher’s Exact test was employed to investigate the relationships between categorical variables. The analyses were conducted using the IBM SPSS 25 software program (IBM SPSS Statistics for Windows, Version 25.0. Armonk, NY, USA).

Results

Between 2010 and 2020, 96 pediatric patients (63 boys and 33 girls, aged 4–12 years) underwent dental treatment under N₂O-O₂ inhalation sedation. Archival records were reviewed, evaluating 162 dental procedures performed across 128 sedation sessions. Patients received dental procedures under N₂O-O₂ inhalation sedation, with varying frequencies: 79 patients received it once, 12 patients received it twice, 2 patients received it three times, and 3 patients received it four times, for a total of 128 sedations. A total of 128 sedation procedures were performed with no reported adverse effects, representing a 100% success rate, since success was defined in our study as completing the planned procedure using only N₂O–O₂ inhalation sedation without the need for any additional sedative or anxiolytic agent. 34.37% of the procedures were performed on girls, while the remaining 65.63% were conducted on boys as illustrated in Fig. 1.

Fig. 1.

Distribution of sedation years among pediatric patients based on gender

The frequency of N₂O-O₂ inhalation sedation used for dental procedures that cannot be performed in a conventional clinical setting due to dental anxiety varies over time, as illustrated in Fig. 2.

Fig. 2.

Annual distribution of N₂O-O₂ inhalation sedation procedures

Additionally, the participants in this study ranged from 4 to 12 years of age. The study examined the relationship between patient ages and the distribution of sedation years using the Fisher’s Exact test. No side effects were observed in this study. The analysis revealed a statistically significant association between age and sedation year. In 2019, the majority of individuals were observed to be in the 7–8 age range, while in 2013, the majority were in the 4–6 age range (p < 0.05) as shown in Table 1.

Table 1.

The distribution and relationships of sedation years among pediatric patients based on their ages

Age	2010		2011		2013		2014		2016		2017		2018		2019		2020		Test Statistics	p
	n	%	n	%	n	%	n	%	n	%	n	%	n	%	n	%	n	%
4–6	0	0.0	9	42.9	5	83.3	2	50.0	5	33.3	16	34.8	3	15.0	3	25.0	0	0.0	39.296	0.004*
7–8	2	100.0	3	14.3	1	16.7	1	25.0	8	53.3	19	41.3	11	55.0	9	75.0	2	100.0
9–10	0	0.0	5	23.8	0	0.0	1	25.0	0	0.0	11	23.9	5	25.0	0	0.0	0	0.0
11–12	0	0.0	4	19.0	0	0.0	0	0.0	2	13.3	0	0.0	1	5.0	0	0.0	0	0.0

The minimum duration of sedation was 15 min, and the maximum was 50 min, with a median of 30.14 min. In this study, a total of 162 dental procedures were performed during 128 sedation sessions. The majority of these procedures were tooth extractions (66.08%) and restorative treatments (32.09%). Out of the 162 dental procedures, only 4 were endodontic treatments (2.46%), 1 was a vital pulp therapy (0.61%), 1 was a gingival surgery (0.61%) and 1 was an impression taking for a space maintainer (0.61%). The study found that the majority of dental procedures were performed on posterior teeth rather than anterior teeth in both primary and permanent dentition.

The distribution of dental procedures performed on pediatric patients according to sedation years is presented in Table 2, and no statistically significant relationship was found between the performed dental procedures and the year of sedation. (p > 0.05)

Table 2.

The distribution and relationships of sedation years based on the dental procedures performed

Dental Procedures	Years																		Test Statistics	p
	2010		2011		2013		2014		2016		2017		2018		2019		2020
	n	%	n	%	n	%	n	%	n	%	n	%	n	%	n	%	n	%
Restorative treatment	1	12.5	14	16.7	2	8.3	2	12.5	1	1.7	22	12.0	4	5.0	4	8.3	2	25.0	40.391	0.774
Vital pulp treatment	0	0.0	1	1.2	0	0.0	0	0,0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0
Endodontic treatment	0	0.0	1	1.2	0	0.0	0	0.0	0	0.0	2	1.1	1	1.3	0	0.0	0	0.0
Tooth extraction	2	25.0	6	7.1	5	20.8	2	12.5	17	28.3	38	20.7	22	27.5	10	20.8	1	12.5
Space maintainer	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	1	0.5	0	0.0	0	0.0	0	0.0
Gingival surgery	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	1	0.5	0	0.0	0	0.0	0	0.0

Discussion

Dental anxiety in pediatric patients is a multifactorial condition influenced by psychological, developmental, and social factors, often requiring a tailored approach to behavior management [17–19]. While non-pharmacological techniques are preferred as first-line strategies, pharmacological methods such as nitrous oxide–oxygen (N₂O–O₂) inhalation sedation have become increasingly important, especially when behavioral interventions prove inadequate [6, 7]. This retrospective study demonstrated the clinical efficacy and safety of N₂O–O₂ sedation in a pediatric population, with no reported adverse events during or after the 128 sedation sessions—a finding that aligns with prior research emphasizing its favorable safety profile [9, 10, 20, 21].

In the study by McDonald et al. [22], nitrous oxide was emphasized as a well-established sedative agent offering anxiolysis and mild analgesia, with minimal risk of overdose due to its titrability and rapid elimination. Consistent with this, our findings showed successful completion of various dental procedures—including restorations, extractions, and limited endodontic treatments—without any intraoperative complications. Moreover, our results further corroborate the clinical guidance of the American Academy of Pediatric Dentistry [23], which supports the use of N₂O–O₂ inhalation sedation for ASA I and II children, as was the case with all patients in our sample. Individuals classified as Physical Status I or II by the American Society of Anesthesiologists are considered suitable candidates for N₂O-O₂-based analgesia and anxiolysis [24], and in the present study, pediatric patients meeting these criteria were sedated.

The distribution of treatments observed in our study notably resembled that reported in Hill et al. [25], where nitrous oxide sedation facilitated routine care in patients with complex medical needs, such as sickle cell disease. Although our study excluded children with severe systemic conditions, the absence of complications across diverse treatment types reinforces the reliability of this technique even in extended procedural settings. Furthermore, the sedation duration in our study ranged from 15 to 50 min, primarily depending on the invasiveness of the dental procedure. This is in agreement with the findings of Holroyd [10], who emphasized the short onset and recovery times of nitrous oxide, enabling flexible use even in clinics with limited sedation infrastructure.

According to the European Academy of Pediatric Dentistry (EAPD) policy document, reported adverse effects of N₂O–O₂ inhalation sedation include hiccups, nausea, respiratory depression, interactions with other medications, paradoxical reactions, over-sedation, and hallucinations [20]. The most common adverse effects are nausea and vomiting, seen in 0.5-2.5% of patients [26, 27]. Some studies also note rare occurrences of mild oropharyngeal numbness or ear pressure with administration duration exceeding 45–60 min with higher N₂O concentrations [28, 29]. While N₂O-O₂ inhalation sedation may have some potential side effects, the data from this study indicate that none of these side effects were observed in our patients. In this retrospective study examining the application of N₂O-O₂ inhalation sedation for dental treatments in the pediatric patient population, the most notable finding was the complete absence of any life-threatening adverse effects or complications during the intraoperative and postoperative periods.

Interestingly, while prior meta-analyses by Sivaramakrishnan and Sridharan [11] and Melini et al. [12] have compared various sedation regimens (including midazolam, ketamine, and their combinations), our study focused solely on inhalational sedation using N₂O–O₂. Nevertheless, our data echo their conclusions regarding high patient tolerance and procedural success. Unlike oral sedatives—which often carry the risk of delayed recovery and variable pharmacokinetics—nitrous oxide offers more predictable outcomes, particularly advantageous in pediatric settings.

Hennequin et al. [30] reported a 93.7% success rate for sedation and treatment using a 50% N₂O-O₂ premix, with no serious adverse events and only about 10% of patients experiencing mild behavioral, vagal, or gastrointestinal effects. Similarly, a large prospective survey of 35,828 N₂O-O₂ administrations found adverse events in just 4.4%—mostly minor gastrointestinal or neuropsychiatric symptoms—and a serious-event rate of only 0.03% [31]. Our study’s high sedation success and low complication rate closely mirror these results, further supporting the safety and efficacy of a 50% N₂O-O protocol in comparable clinical settings.

Mourad’s six-year retrospective analysis of pediatric patients [16] treated with N₂O–O₂ inhalation sedation demonstrated an 84% success rate for complete oral rehabilitation. The study also noted that the patient cohort comprised predominantly younger children who had been referred due to cooperation-related difficulties and were classified as semi-cooperative. This finding is particularly important, as nitrous oxide–oxygen sedation entails a lower morbidity risk compared to treatment under general anesthesia. Therefore, even in semi-cooperative pediatric patients, N₂O–O₂ inhalation sedation should be considered as an intermediate approach before electing general anesthesia.

Another study from Galeotti et al. [32] demonstrates that while N₂O–O₂ inhalation sedation can be an effective alternative to general anesthesia in precooperative, fearful, and disabled pediatric dental patients, success rates differ significantly depending on patient cooperation and health status. In their large survey of 688 sedation sessions, the failure rate was notably higher among disabled children compared to healthy counterparts, indicating that underlying disabilities and lack of cooperative behavior substantially increase the likelihood of sedation failure. In contrast, healthy children with dental anxiety, though fearful, tend to be more potentially cooperative once properly prepared, which aligns with our inclusion of ASA I–II patients who were anxious but otherwise healthy. These findings underscore the critical role of careful case selection in achieving optimal outcomes with N₂O–O₂ sedation.

By reviewing ten years of patient records, this retrospective study provides a detailed and extensive picture of nitrous oxide-oxygen sedation practices in pediatric dentistry. However, as also discussed by Araújo et al. [13], the lack of standardized outcome assessments across sedation studies hinders direct comparison. We echo this concern and recognize that future studies would benefit from the use of validated sedation success and patient anxiety scales, such as the Venham scale or the Modified Child Dental Anxiety Scale.

Nonetheless, our study is not without limitations. The retrospective and single-center design constrains the generalizability of the findings. Additionally, the absence of long-term follow-up restricts insight into delayed adverse events and the longitudinal behavioral effects of sedation. Similar to the observations made by Becker and Kuperberg [33], future studies should consider incorporating follow-up appointments to evaluate whether N₂O–O₂ inhalation sedation reduces anxiety in subsequent dental visits or affects future dental attendance patterns.

Considering that our dataset only goes up to 2020, our observations of sedation case numbers largely reflect pre-pandemic dynamics. The COVID-19 pandemic curtailed healthcare access, leading to a sharp decline in pediatric dental service utilization in all over the world, including Türkiye [34]. Since COVID-19 began affecting Türkiye in the first quarter of 2020, the decrease seen that year should be viewed separately from the gradual decline that occurred beforehand; after all, our study only captured cases from the very beginning of 2020. In other words, because the pandemic’s restrictions and patient-flow changes had not yet fully materialized during the period included in our analysis, the drop in sedation numbers is driven more by earlier shifts, such as revisions to the university hospital’s patient-referral strategies.

The Health Transformation Program (HTP), implemented in 2003, and the shift toward performance-based reimbursement fundamentally reshaped hospital financing and patient-management pathways in Türkiye over the years [35]. As a result, the case mix at our university clinic shifted: the overall number of sedation procedures dropped, while the number of patients treated in the outpatient clinic increased. Under these conditions, N₂O–O₂ inhalation sedation incurs additional costs for equipment, monitoring, and specialized personnel, yet does not yield proportional financial return, causing clinics to limit its use to cases of absolute necessity. Consequently, less profitable procedures—such as sedation-based treatments—are often deferred or avoided, especially in high-caseload settings, where resources must be allocated to services that align with the program’s efficiency-driven goals. This economic environment helps explain the low number of sedation cases recorded in our department, despite clinical indications, as both public clinics and academic centers face pressure to optimize revenue under HTP mandates.

Unlike other countries, Türkiye currently lacks clear legislative guidance on dentists’ authority for pharmacological behavior management, as Law No. 1219 does not define their role in sedation [36]. This gap has resulted in inconsistent accreditation and unclear postgraduate requirements for dental sedation. Furthermore, the Turkish Anesthesiology and Reanimation Society guidelines require that sedation and general anesthesia in dentistry be performed only in operating-room–standard facilities equipped for advanced respiratory and circulatory support, since patients may unexpectedly deepen their sedation level [37]. These provisions, together with Işık et al.’s conclusion that only anesthesiology specialists and adequately trained dentists may administer N₂O–O₂ inhalation sedation [37], help explain why most clinics and specialists defer nonessential sedation cases.

The year-to-year shift in age-group distribution is not merely a reflection of evolving clinical preferences; it represents the combined impact of policy-driven constraints. Once the possibility of requiring an anaesthesiologist for every dental sedation entered the agenda, regulatory uncertainty led many centres to trim their eligible patient pool, offering sedation almost exclusively to highly anxious younger children (4–6 years). After 2016, rules were not clarified but the case mix widened again, allowing more school-age children (especially 7–8 years) to receive inhalation sedation. However, the way these nation-wide regulatory swings translated into everyday practice was further conditioned by our department’s own resource limitations and teaching-driven priorities.

Moreover, within Ege University Faculty of Dentistry’s Department of Pediatric Dentistry, only a single N₂O–O₂ inhalation sedation unit was available, and—given its primary role as a teaching institution—routine patient treatment under sedation was not prioritized. In 2018–2019, our department admitted approximately 12,500 patients in a single year, all of whom were managed mostly by dental students, resident dentists, and faculty members [34]. Sedation-based procedures, however, were restricted to those faculty members with specific expertise in N₂O–O₂ inhalation techniques, as training priorities focused on undergraduate and postgraduate clinical education. Consequently, the combination of pandemic measures, regulatory delays, limited equipment resources, and the necessity to reserve sedation cases for experienced instructors largely explains the comparatively low number of sedated cases observed in our study.

In summary, our findings reinforce existing literature that supports the use of N₂O–O₂ inhalation sedation in pediatric dentistry as a safe, efficient, and well-tolerated option for managing dental anxiety. It enables successful completion of a broad range of procedures, minimizes adverse effects, and upholds patient cooperation—an outcome particularly valuable in uncooperative or phobic children.

Conclusion

In cases where basic behavioral guidance is insufficient for managing dental treatments in systemically healthy pediatric patients with dental anxiety, the application of N₂O-O₂ inhalation sedation, particularly for brief procedures such as tooth extraction and filling, can serve as a reliable alternative. N₂O-O₂ inhalation sedation effectively reduces dental anxiety and facilitates pediatric dental treatments with minimal reported adverse effects. Given its safety and efficacy, further studies should explore its long-term impact on patient behavior and treatment adherence.

Abbreviations

ASA

American Society of Anesthesiologists

N₂O-O₂

Nitrous oxide-oxygen

HTP

The Health Transformation Program

Author contributions

BG, SA, and AA contributed to the acquisition, analysis, interpretation of data, and drafting of the work. IU and ÖÖ contributed to the conception, design of the work and substantively revised the work. All the authors have approved the submitted version. All the authors have agreed both to be personally accountable for the author’s contributions and to ensure that questions related to the accuracy or integrity of any part of the work, even ones in which the author was not personally involved, are appropriately investigated, resolved, and the resolution documented in the literature.

Funding

This research has no funding.

Data availability

The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.

Declarations

Ethics approval and consent to participate

The present retrospective study was conducted in full accordance with the World Medical Association Declaration of Helsinki. Before data collection, ethical approval was obtained from Ege University, Faculty of Medicine Non-intervention Clinical Research Ethical Committee (protocol number: 22-2.1T/36, dated February 24, 2022). The dentist explains the procedure to the patient and obtains informed consent before starting the procedure. Informed consent for the publication was obtained through face-to-face or telephone interviews with patients’ legal representatives. Archival data was accessed only after approval. The clinical trial number is not applicable, as the study doesn’t include any interventions.

Consent for publication

Informed consent for the publication was obtained through face-to-face or telephone interviews with patients’ legal representatives.

Competing interests

The authors declare no competing interests.