The use of laser Doppler flowmetry in paediatric dentistry

Assessment of Pulpal Status in Primary Teeth Following Direct Pulp Capping in an Experimental Canine Model

(1) Background: This study aimed to assess the pulpal response of primary teeth by pulse-oximetry (PO) in a canine model, following direct pulp capping (DPC). (2) Methods: Forty-eight primary teeth from eight canine subjects were divided into three treatment groups, based on the DPC material—calcium hydroxide (CH), MTA, BiodentineTM)—and three corresponding control groups. Data from PO pulp testing were correlated with laser Doppler flowmetry (LDF) testing, computer tomographic (CT) densitometry and histological analysis; the experiment lasted 14 days. (3) Results: SpO₂ recordings revealed statistically significant differences (p = 0.002, <0.05) between the treatment and control groups, and no significant differences (p = 0.257, >0.05) were observed between treatment groups. LDF recordings showed significant differences (p = 0.002, <0.05) between the treatment and control groups and identified significant differences between materials (p = 0.001, <0.05). CT densitometry indicated vital pulps in all teeth, with pulpal inflammation detected in 6/8 CH-capped teeth and 2/8 MTA-capped teeth. Histologic evaluation confirmed vital pulp in all specimens, with different degrees of inflammation. (4) Conclusions: Within its limitations, the present study confirms the diagnostic value of PO evaluation of pulpal status in primary teeth with histologic means after pulp-capping procedures in a canine model. However, various degrees of pulpal inflammation elicited by different pulp-capping materials seem not to correlate with the obtained PO values.

Efficacy of Laser Doppler Flowmetry, as a Diagnostic Tool in Assessing Pulp Vitality of Traumatised Teeth: A Split Mouth Clinical Study

Aim: This study aimed to evaluate the efficacy of laser Doppler flowmetry (LDF) in determining the changes in the pulpal blood flow (PBF) during post-traumatic period of the traumatised permanent teeth. Methods: 88 teeth of 44 patients (mean age 10.30 ± 2.38) were recruited according to the eligibility criteria and divided into two groups: test group (44 traumatised teeth) and control group (44 sound and healthy teeth). The measurement of PBF was performed, using a LDF monitor. Results: The analysis of the LDF outcomes in function of diagnosis indicated that the measurements of the traumatised teeth were significantly higher than those of non-traumatised teeth (p ˂ 0.05). Conclusions: LDF application provides dentists with fundamental benefits in terms of an early and precise investigation of PBF. In addition, LDF is a useful monitoring tool for revascularization of traumatised teeth and reliable objective diagnostic indicator of pulp vitality. Trial registration: ClinicalTrials.gov (Registration number: NCT04967456).

Prognostic markers of post-traumatic dental external root resorption in children-a pilot study

BACKGROUND

External inflammatory root resorption (EIRR) is a frequent complication of traumatic dental injuries (TDI). The aim of this cohort study was to identify novel non-invasive markers of post-traumatic EIRR by assessing the changes in the pulp's blood flow and the composition of gingival sulcus fluid (GCF) in children after dental trauma.

MATERIAL AND METHODS

Thirty-two children were enrolled and assessed within 48 h of a TDI to their permanent incisors and during an additional three visits over a 6-months follow up period. During each visit, a radiograph and laser Doppler flow (LDF) measurements of the pulp blood flow were performed on the injured tooth, and the GCF was sampled. The permanent first molar tooth of the same subject served as a control for the LDF measurements and the GCF sampling. Concentrations of IL-1α in the GCF were measured using enzyme-linked immunosorbent assays. Radiographs were used to confirm EIRR.

RESULTS

EIRR occurred in fourteen (43.8%) teeth in 32 patients. The teeth with EIRR showed diminished LDF readings when compared with controls at all visits. The LDF readings of the injured teeth continued to decrease at follow up visits. In the EIRR group, levels of IL-1α in the GCF of teeth with EIRR were increased and significantly higher than those of the control teeth at the visit when EIRR was diagnosed. The IL-1α levels were significantly higher in the EIRR group when compared to the injured teeth of patients without EIRR at the last follow-up visit.

CONCLUSIONS

The occurrence of EIRR after mechanical trauma of permanent teeth with complete root development is accompanied by a significant reduction in the blood flow of the tooth's pulp. It is accompanied by an increase in concentrations of IL-1α in the GCF of EIRR affected teeth. The results of this pilot study identified the use of IL-1α in GCF and LDF as non-invasive markers of EIRR.

The correlation between preputial blood flow and microvessel density in distal hypospadias: a prospective clinical study

OBJECTIVE

A prospective clinical study was designed to investigate the correlation between preputial blood flow (BF) and microvessel density (MVD).

PATIENTS AND METHODS

A total of 44 children were included in the study. The hypospadias group consisted of 16 children undergoing distal hypospadias repair, and the control group consisted of 28 age-matched healthy children undergoing circumcision. BFs were measured using a laser Doppler flowmeter on the most distal part of the dorsal prepuces, and then the tissue samples were harvested from the same location. They were immunostained with an antibody against CD31 in order to assay MVD. The statistical analyses were carried out using Student's t test and Pearson's correlation analysis.

RESULTS

The preputial MVD was found to be significantly decreased in the patients with hypospadias compared with the healthy children (33.95 ± 9.79 vs. 48.25 ± 10.08; p < 0.05), whereas there was no difference in terms of the BF (40.58 ± 16.16 vs. 33.09 ± 19.65; p > 0.05).

CONCLUSIONS

We found no correlation between the preputial MVD and BF in the present study. This result suggests that reduced preputial MVD does not have any influence on BF in distal hypospadias.

Surfing the spectrum - what is on the horizon?

Diagnostic imaging techniques have evolved with technological advancements - but how far? The objective of this article was to explore the electromagnetic spectrum to find imaging techniques which may deliver diagnostic information of equal, or improved, standing to conventional radiographs and to explore any developments within radiography which may yield improved diagnostic data. A comprehensive literature search was performed using Medline, Web of Knowledge, Science Direct and PubMed Databases. Boolean Operators were used and key-terms included (not exclusively): terahertz, X-ray, ultraviolet, visible, infra-red, magnetic resonance, dental, diagnostic, caries and periodontal. Radiographic techniques are primarily used for diagnostic imaging in dentistry, and continued developments in X-ray imaging include: phase contrast, darkfield and spectral imaging. Other modalities have potential application, for example, terahertz, laser doppler and optical techniques, but require further development. In particular, infra-red imaging has regenerated interest with caries detection in vitro, due to improved quality and accessibility of cameras. Non-ionising imaging techniques, for example, infra-red, are becoming more commensurate with traditional radiographic techniques for caries detection. Nevertheless, X-rays continue to be the leading diagnostic image for dentists, with improved diagnostic potential for lower radiation dose becoming a reality.

Laser physics and a review of laser applications in dentistry for children

AIM

The aim of this introduction to this special laser issue is to describe some basic laser physics and to delineate the potential of laser-assisted dentistry in children.

REVIEW

A brief review of the available laser literature was performed within the scope of paediatric dentistry. Attention was paid to soft tissue surgery, caries prevention and diagnosis, cavity preparation, comfort of the patient, effect on bacteria, long term pulpal vitality, endodontics in primary teeth, dental traumatology and low level laser therapy. Although there is a lack of sufficient evidence taking into account the highest standards for evidence-based dentistry, it is clear that laser application in a number of different aetiologies for soft tissue surgery in children has proven to be successful. Lasers provide a refined diagnosis of caries combined with the appropriate preventive adhesive dentistry after cavity preparation. This will further lead to a new wave of micro-dentistry based on 'filling without drilling'.

CONCLUSION

It has become clear from a review of the literature that specific laser applications in paediatric dentistry have gained increasing importance. It can be concluded that children should be considered as amongst the first patients for receiving laser-assisted dentistry.