Effective Parameters for Orthodontic Tooth Movement Acceleration with Photobiomodulation: An Umbrella Review.

Objective: To answer this research question: What are the effective wavelength, power, and energy density parameters for achieving dental movement acceleration? Background Data: Photobiomodulation (PBM) has been clinically studied for its ability to accelerate dental movements in orthodontics. However, its effectiveness is dose dependent. Methods: The search was carried out in PubMed, SCOPUS, and ISI Web of Science. The quality of the included systematic reviews was performed using the AMSTAR 2 tool. The risk of bias was assessed using the ROBIS tool. Results: In total, 29 articles in PubMed, 75 in Scopus, and 61 in ISI Web of Science. Finally, only five systematic reviews were included. Conclusions: The results showed the range from 730 to 830 nm as the most effective range of wavelength to accelerate the orthodontic dental movement. A power range of 0.25-200 mW, with emphasis on the direct correlation between power, wavelength, and energy density. Energy density has not been adequately reported in the most randomized controlled clinical trials.

Substance P/calcitonin gene-related peptide and their receptors expression in human periodontal ligament after root canal preparation with five different systems.

AIM: The purpose of this study was to quantify the effect of five different root canal preparation instruments on Substance P (SP), Calcitonin gene-related peptide (CGRP) and their receptors expression in healthy human periodontal ligament. METHODOLOGY: STROBE guidelines were used to design a study using 60 periodontal ligament samples obtained from healthy lower premolars where extraction was indicated for orthodontic reasons. Prior to extraction 40 of these premolars were equally divided into four groups and root canals were prepared using different systems: Mtwo, Reciproc Blue, HyFlex EDM and Plex-V. Ten premolars were prepared with hand files and served as a positive control group. The remaining 10 premolars where extracted without treatment and served as a negative control group. All periodontal ligament samples were processed to measure the expression of SP, CGRP and their receptors by radioimmunoassay. Kruskal-Wallis and Duncan tests were performed to determine statistically significant differences between the groups for each variable. RESULTS: Greater expression of all the peptides measured were found in the hand-file preparation group, followed by the Reciproc Blue, Mtwo, HyFlex EDM and Plex-V groups. The lower SP, CGRP and their receptors values were for the intact teeth control group. Kruskal-Wallis test showed statistically significant differences amongst groups (p < .001). Dunn post-hoc tests showed statistically significant differences in SP, CGRP and their receptors expression between the intact teeth and the hand-file and Reciproc Blue groups. Hand-file group showed significant differences with the other groups, except with Reciproc Blue, where no differences were observed in any of the peptides measured. Finally, no differences were observed between Plex-V and HyFlex in any of the peptides measured. CONCLUSIONS: Root canal preparation with hand files and Reciproc Blue generates the highest expression of SP, CGRP, NK1 and CGRP1R in human periodontal ligament, whilst Plex-V and HyFlex maintain the basal expression of neuropeptides and their receptors. Mtwo showed intermediate results between Reciproc Blue and HyFlex.

Comparative outcomes of platelet concentrates and blood clot scaffolds for regenerative endodontic procedures: A systematic review of randomized controlled clinical trials.

Background: The main objective of this systematic review is to evaluate the effectiveness of platelet concentrates -Platelet-rich plasma (PRP) or Fibrin-rich plasma (PRF)- compared with blood clot (BC) as scaffolds for maturogenesis, in patients with immature permanent teeth with or without AP, in terms of the criteria for pulp revascularization success. Material and Methods: We reviewed randomized controlled clinical trials comparing regenerative endodontic therapies (maturogenesis) based on PRP or PRF versus the conventional BC approach, in necrotic teeth with or without apical periodontitis (AP) under clinical and radiographic criteria. We performed a strategic search in MEDLINE (PUBMED), EMBASE, and ISI Web of Science from inception to October 2022. This systematic review of the literature was developed following the Cochrane Collaboration and PRISMA statement recommendations. We used the Cochrane risk of bias tool v2 to assess the included studies' quality. We performed a qualitative synthesis of the evidence. Results: Ten randomized controlled clinical trials were included in this systematic review. Analyses of these studies suggest that maturogenesis is a successful therapy regardless of the method employed. However, further research should be conducted with more suitable research methodologies and more homogenous data for meta-analysis. Conclusions: Results from this systematic review suggest that BC maturogenesis approaches yield similar clinical and radiographic outcomes when compared to Platelet-concentrates based therapies (PRP and PRF). Key words:Maturogenesis, Revascularization, Platelet-rich plasma, Fibrin-rich plasma, blood clot, systematic review.

The effect of orthodontic forces on calcitonin gene-related peptide (CGRP) expression in the human periodontal ligament and its relationship with the human dental pulp.

Background: The purpose of this study was to quantify the effect of moderate and severe orthodontic forces on Calcitonin gene-related peptide (CGRP) expression in the healthy human periodontal ligament (PDL) and its possible relationship with the human dental pulp. Material and Methods: Ninety human periodontal ligament samples were obtained from healthy premolars where extraction was indicated for orthodontic reasons. Prior to extraction, teeth were divided in 3 groups of 30 samples each: I) Untreated teeth control group; II) Moderate force group: A 56 g force was applied to the premolars for 24 hours; and III) Severe force group: A 224 g force was applied to the premolars for 7 days. All periodontal ligament samples were processed and CGRP was measured by radioimmunoassay. Results: Greater CGRP expression was found in the severe force group, followed by the moderate force group. The lower CGRP values were for the untreated teeth. Kruskal-Wallis test showed statistically significant differences between groups (p<0.001). LSD post hoc tests showed statistically significant differences in CGRP expression between the untreated teeth and the severe forces group (p<0.001). Differences between the moderate and severe force groups were statistically significant (p<0.001). There was no statistically significant differences between the untreated teeth and the moderate forces group (p<0.261). Conclusions: CGRP expression in human periodontal ligament increases when teeth are submitted to severe orthodontic forces. This elevated expression of CGRP, which is proportional to the applied force, may affect the way the dental pulp responds to different stimuli from the orthodontic forces. Key words:Calcitonin gene-related peptide, orthodontic force, human periodontal ligament, neurogenic inflammation.

Association between cigarette smoking and the prevalence of post-endodontic periapical pathology: a systematic review and meta-analysis.

Objectives: This systematic review and meta-analysis aimed to assess the association of cigarette smoking with the prevalence of post-endodontic apical periodontitis in humans. Materials and Methods: We searched through PubMed/Medline, Web of Science, and Scopus from inception to December 2020. Risk of bias was performed by using the Newcastle-Ottawa Scale for cross-sectional, cohort, and case-control studies. We performed the statistical analysis in Review Manager 5.3 (RevMan 5.3). Results: 6 studies met the inclusion criteria for qualitative and quantitative synthesis. Statistical analysis of these studies suggests that there were no differences in the prevalence of post endodontic apical periodontitis (AP) when comparing non-smokers vs smoker subjects regarding patients (odds ratio [OR], 0.68; 95% confidence interval [CI], 0.31-1.49; I2 = 58%) and teeth (OR, 1.71; 95% CI, 0.99-2.93; I2 = 72%). Conclusions: Our findings suggest that there was no association between cigarette smoking and post-endodontic apical periodontitis, as we did not find statistical differences in the prevalence of post-endodontic AP when comparing non-smokers vs smoker subjects. Therefore, smoking should not be considered a risk factor associated with endodontic failure.

Expression of substance P, calcitonin gene-related peptide and vascular endothelial growth factor in human dental pulp under different clinical stimuli.

BACKGROUND: The aim of this study was to measure the dental pulp inflammatory response through neuropeptides (SP and CGRP) as a response to occlusal trauma, orthodontic movements and a combination of both, as well as the angiogenic defense mechanism through VEGF expression, which could be the initial step to mineralized tissue formation. METHODS: Forty human dental pulp samples were collected from healthy first premolars with extraction indicated due to orthodontic reasons from a sample of 20 patients. Patients were divided into four groups with 10 premolars each (1 mandibular and 1 maxillary premolar from each patient): healthy pulp control group, occlusal trauma group, moderate orthodontic forces group; and occlusal trauma plus moderate orthodontic forces group. Stimuli were applied for 24 h before tooth extraction in all experimental groups. All samples were processed, and SP, CGRP, and VEGF were measured by radioimmunoassay. The Kruskal-Wallis test was performed to assess significant differences among groups and Mann-Whitney's U post hoc pairwise comparisons were also performed. RESULTS: The highest increase in SP, CGRP, and VEGF expressions was found in the occlusal trauma plus orthodontic forces group, followed by the moderate orthodontic forces, the occlusal trauma and the control groups, with statistically significant differences between all groups for each of the 3 peptides analyzed (Kruskal-Wallis p < 0.001). All possible pairwise post-hoc comparisons were also significant for each peptide analyzed (Mann-Whitney's U p < 0.001). CONCLUSION: SP, CGRP, and VEGF expressions significantly increase in human dental pulps when stimulated by occlusal trauma combined with moderate orthodontic forces, as compared with these two stimuli applied independently. Name of the registry: Importance of Neurogenic Inflammation in the Angiogenic Response of the Dental Pulp as a Defensive Response. TRIAL REGISTRATION NUMBER: NCT03804034. Date of registration: 01/15/2019 Retrospectively registered. URL of trial registry record: https://clinicaltrials.gov/ct2/show/NCT03804034?term=NCT03804034&draw=2&rank=1 .

Expression of early angiogenesis indicators in mature versus immature teeth.

BACKGROUND: Proper oxygen balance in the dental pulp is essential for cell metabolism. Angiogenesis in the pulp is a constant process during the life of the tooth. Hypoxia indicators in a tissue, such as HIF-1α, as well as vascular destabilization markers, such as ANG2 and its receptor TIE2, are necessary for angiogenesis. Therefore the purpose of this study is to evaluate the expression of HIF-1α, ANG1, ANG2 and TIE2 in dental pulp as early angiogenesis indicators in teeth with complete and incomplete root development. METHODS: Forty human dental pulps were obtained from freshly extracted third molars divided into two groups: incomplete (n = 20) and complete (n = 20) root development. Dental pulps were stored at - 80 °C, defrosted in an ice bath and re-frozen with their respective thaws to disintegrate the tissue. Three sonication cycles were performed until the tissues were homogenized, then thaw were centrifuged and the supernatant was collected for the detection of the markers to be studied. The samples were processed for the ELISA test using the ELISA-sandwich principle. Student t and Mann-Whitney U tests were performed to determine statistically significant differences between groups. RESULTS: In the complete root development, HIF-1α, ANG1, ANG2 and TIE2 expressions were significantly higher than their expression in the incomplete root development group. CONCLUSIONS: The angiogenic process seems to be a physiological process in the dental pulp. Angiogenic activity is higher in teeth with mature than immature apex teeth.

Association between type 2 diabetes mellitus and the evolution of endodontic pathology.

OBJECTIVE: The purpose of the present study was to assess the influence of type 2 diabetes mellitus (DM) on the evolution of pulpal and periapical pathology. METHOD AND MATERIALS: Two reviewers independently conducted a systematic search for articles published between 1 January 2001 and 31 December 2018 on MEDLINE/PubMed, ISI Web of Science, and Scopus databases. An additional manual search was also carried out. RESULTS: Ten studies fulfilling the inclusion criteria were included in the review (two longitudinal studies with 1-year follow-up comparing the success of primary root canal treatment between type 2 diabetic patients and non-diabetic patients, and eight cross-sectional studies). Analysis of the ten studies showed that inadequate control of type 2 DM may predispose and influence the inflammatory pulpal and periapical disease evolution. CONCLUSIONS: The present systematic review suggests that there are biologic bases to suggest that type 2 DM may act as a risk factor for developing an endodontic pathology, affecting the course of the disease in terms of susceptibility, prevalence, progression, and tissue healing capacity as a consequence of a disrupted immune response. However, more well-designed clinical investigations carrying out suitable research methodologies are needed to elucidate the influence of type 2 DM on the pulpal and periapical disease evolution.