Comparison of dynamic cyclic fatigue resistance of Reciproc® Blue and WaveOne® Gold after sterilization and/or immersion in sodium hypochlorite.

Background: This study aims to compare the cyclic fatigue resistance (CFR) of the Reciproc Blue and WaveOne Gold instruments under a dynamic cyclical fatigue test. Material and Methods: 210 Reciproc Blue "R25" and WaveOne Gold "primary" files were assigned into 7 groups (n =15) for each brand. Groups G: Files were not exposed to NaOCl or sterilization. Groups A and D: files were immersed for 3 minutes in NaOCl 1 and 3 times, respectively. Groups B and E: Files were autoclaved 1 and 3 times, respectively. Groups C and F: files were exposed to both, NaOCl immersion and autoclaving 1 and 3 times, respectively. Subsequently, files underwent a dynamic CFR test. The chemical composition of the files' surface from Group G was analysed by energy-dispersive X-ray spectroscopy (EDS). Cyclic fatigue resistance time was statistically analysed using 1-way and 2-way analyses of variance (ANOVA) and T-test. A p-value ≤0,05 was set to be statistically significant. Results: There was a significantly higher CFR of RB files than WOG in groups A, B, C, D and G (p<0.05). WOG files were superior to RB in group E (p>0.05). There were no statistically significant differences between files in group F (p>0.05). RB files from groups B, C, D, E and F had significantly lower resistance than new ones (Group G) (p<0.05). WaveOne Gold files exposed to 5 % NaOCl immersion in combination with sterilization cycles (Groups C and F) had significantly lower CFR than new ones (p<0.05). Reciproc Blue and WaveOne Gold NiTi alloys differed in atomic wt % of carbon, oxygen, nickel and titanium. Conclusions: The Reciproc Blue files outperformed the WaveOne Gold files in terms of CFR. The Reciproc Blue files were more vulnerable to the cycles of NaOCl immersion or autoclave sterilisation. The combined autoclaving and NaOCl cycles had the most significant impact on the mechanical properties of both files. Key words:Cyclic fatigue, Reciproc blue, Wave one gold, Dynamic test, Simulated channels, Sodium hypochlorite, Sterilization.

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.

Effectiveness, efficiency, and apical extrusion of 2 rotaries and 2 reciprocating systems in removing filling material during endodontic retreatment. A systematic review.

Background: This systematic review investigated the effectiveness, efficiency and apical extrusion of the debris of two rotary and two reciprocating single-file systems used for the removal of filling material from straight root canals. Material and Methods: A literature search was performed in the Medline, ISI Web of Science, and Scopus databases for relevant articles matching the keyword search strategy. Effectiveness was determined with studies dealing with the ability of the instruments to remove filling material from root canals. Efficiency was assessed with studies dealing with the time needed to completely remove the root canal filling, and apical extrusion was determined with studies that measured the amount of filling material extruded through the apex. Results: From the 424 articles initially found, 406 were excluded for being non-relevant or not fulfilling the selection criteria. Another 9 articles were excluded after methodology evaluation. Finally, 9 studies were included in the systematic review. Conclusions: None of the reviewed systems is effective to completely remove the filling materials from straight root canals, and all systems appear to be equally time-efficient, although this variable shows different results. In terms of apical extrusion, the analyzed reciprocating systems extrude more material toward the periapical tissues than the continuous rotation systems. Key words:Systematic review, rotary files, reciprocating files, apical extrusion, endodontic retreatment.

The Paradigm of the Inflammatory Radicular Cyst: Biological Aspects to be Considered.

Inflammatory radicular cysts (IRCs) are chronic lesions that follow the development of periapical granulomas (PGs). IRCs result from multiple inflammatory reactions led initially by several pro-inflammatory interleukins and growth factors that provoke the proliferation of epithelial cells derived from epithelial cell rests of Malassez present in the granulomatous tissue, followed by cyst formation and growth processes. Multiple theories have been proposed to help explain the molecular process involved in the development of the IRC from a PG. However, although multiple studies have demonstrated the presence of epithelial cells in most PGs, it is still not fully understood why not all PGs turn into IRCs, even though both are stages of the same inflammatory phenomenon and receive the same antigenic stimulus. Histopathological examination is currently the diagnostic gold standard for differentiating IRCs from PGs. Although multiple studies have evaluated the accuracy of non-invasive or minimally invasive methods in assessing the histopathological nature of the AP before the intervention, these studies' results are still controversial. This narrative review addresses the biological insights into the complex molecular mechanisms of IRC formation and its histopathological features. In addition, the relevant inflammatory molecular mediators for IRC development and the accuracy of non-invasive or minimally invasive diagnostic approaches are summarised. (EEJ-2022-03-041).

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.

In Vitro Comparison of MTA and BC RRM-Fast Set Putty as Retrograde Filling Materials.

OBJECTIVE: To compare, in vitro, the bioceramic materials (MTA and BC RRM-fast set putty) capacity to prevent microleakage of Enterococcus faecalis over time. METHODS: An experimental design was made with forty extracted human teeth, coronally cut, and prepared to be placed in a leakage system under sterile conditions. They were randomly divided into two experimental groups: thirty teeth (fifteen for each of retrograde filling material MTA and BC RRM-fast set putty) and a control group: ten teeth (five positive control, five negative control). The 3 mm root-ends were submerged in a brain-heart infusion broth with a red phenol indicator. The coronal access of each sample was inoculated with E. faecalis every seven days to maintain bacterial viability. The lower chamber was evaluated daily for 30 days to observe the turbidity of the culture medium and establish the presence and day of the filtration. Calculation of the colony-forming units (CFU) was performed for each leaked sample. Fisher's Exact Test was used to verify the association between the presence or absence of leakage of the samples by type of bioceramic material used and the Mann-Whitney U test to verify the existence of a difference between the average of CFU by type of bioceramic material used. The significance level used was α=0.05 and a 95% confidence level, as a decision rule for rejecting the null hypothesis. RESULTS: Of the total samples prepared for each group, leakage was found in 60.0% (9/15) of the MTA group and 40.0% (6/15) of the BC RRM-fast set putty group. All positive controls filtered on the first day of evaluation, while 20% (1/5) of the negative control leaked in the second week. There was no significant difference in leakege between the two groups, nor concerning the bacterial count (P=0.101) and the type of cement used (P=1.000). CONCLUSION: BC RRM-fast set putty was comparable to MTA in resisting bacterial microleakage during the observation time.

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.

The hypoxia-dependent angiogenic process in dental pulp.

BACKGROUND: In this review, we analyzed the existing literature to elucidate how the hypoxia-dependent angiogenic processes work in dental pulp. Angiogenesis is an essential biological process in the maturation and homeostasis of teeth. It involves multiple sequential steps such as endothelial cell proliferation and migration, cell-to-cell contact, and tube formation. HIGHLIGHT: Clinical implications of understanding the process of angiogenesis include how the mineralization processes of dental pulp occur and how dental pulp maintains its homeostasis, preventing irreversible inflammation or necrosis. CONCLUSION: The angiogenesis process in dental pulp regulates adequate concentrations of oxygen required for mineralization in root development and defense mechanisms against chronic stimuli.

Use of scaffolds and regenerative materials for the treatment of immature necrotic permanent teeth with periapical lesion: Umbrella review.

BACKGROUND: Current treatment of immature necrotic permanent teeth with a periapical lesion is regenerative endodontics, which is based on tissue engineering under the triade of stem cells, scaffolds and bioactive molecules. OBJECTIVES: This Umbrella Review was aimed to evaluate the success of scaffold and regenerative materials used for the treatment of these teeth, in terms of apical closure, tooth length increase, widening of root canal walls, tissue vitality and periapical lesion repair. METHODS: An extensive literature research was carried out in the Medline, ISI Web of Science, and Scopus databases for relevant systematic reviews matching the keyword search strategy. Based on inclusion and exclusion criteria, reviewers independently rated the quality of each study to determine their level of evidence. Methodological quality assessment of each article was obtained using A Measurement Tool to Assess Systematic Reviews (AMSTAR)-2 tool, and risk of bias was assessed with the Risk of Bias in Systematic Reviews (ROBIS) tool. RESULTS: After removing duplicates, 155 articles were found; from which 133 were excluded for being non-relevant and 15 other due to exclusion criteria. One more was discarded after methodological quality evaluation, for a total of six articles remaining. The most common scaffold used was the blood clot, others used were poly lactic-co-glycolic acid and platelet-rich fibrin matrix. The most common regeneration material used was Mineral Trioxide Aggregate (MTA), followed by Biodentine. An increase in tooth length and widening of root canal walls were reported in all selected studies with different proportions, as well as periapical lesion repair. ROBIS analysis showed that only one article had low bias, two were classified as unclear bias, while the remaining three had high risk of bias. DISCUSSION: An exhaustive literature search was carried out applying language filters, high-quality indexed journals, year of publication, which ensures the best quality articles were included. Blood clot was the most used scaffold as is the most easy to place inside the canal and does not require to extract blood from the patient. The use of MTA and Biodentine as sealing materials has been associated with thickening of canal walls, apical closure and reduced signs and symptoms of apical periodontitis. However, most of the included reviews assessed were case reports and only in a few of them were clinical trials included. There is also a lack of risk of bias analysis in most reviews. CONCLUSION: The blood clot is the most common scaffold used for inducing regeneration during the treatment of immature necrotic teeth. Tooth length increase and widening of root canal walls are the most common criteria used in the studies as success indicators. MTA and Biodentine did not show differences in the results analysed. Quality assessment and bias risk evaluation showed that it is necessary to design better studies with rigorous methodology to recommend a trustable and predictable protocol for the treatment of immature necrotic permanent teeth with periapical lesions. REGISTRATION: International Prospective Register of Systematic Reviews (PROSPERO) CRD42021248404.

Gene Expression of Vascular Endothelial Growth Factor A and its Receptors in Dental Pulp of Immature and Mature Teeth.

OBJECTIVE: Vascular endothelial growth factor A (VEGFA) and its receptors are essential proteins for the angiogenic activity of dental pulp. Angiogenesis fundamentally provides oxygen and nutrients to cells for root formation and defence mechanisms. The angiogenic potential of dental pulp should be understood and considered for the conservative and regenerative endodontics. The purpose of this research was to measure the VEGFA expression and its receptors such as vascular endothelial growth factor receptors 1, -2 (VEGFR1, VEGFR2) and Neuropilin 1 (NRP1) in human dental pulp from molars with immature and mature apexes. METHODS: VEGFA system mRNAs expressions were assessed in dental pulp obtained from freshly extracted human third molars divided into immature (n=8) and mature (n=8) apexes. RNAs were extracted from the samples. Each sample's cDNA was synthetized and the target genes VEGFA, VEGFR1, VEGFR2, NRP1 expression profiles obtained by RT2-PCR. Analysis was based on the Student's t-test comparing the replicate 2-ΔCt values for each gene. P values of <0.05 were considered significant. RESULTS: In teeth with mature apexes, VEGFA (P=0.0002), NRP1 (P=0.0001), VEGFR1 (P=0.0057) and VEGFR2 (P=0.018259) significantly increased statistically with respect to the immature apexes group. CONCLUSION: Within the limitation of the present investigation, it can be concluded that the angiogenic process seems to be a physiological process in the dental pulp due to the studied angiogenic growth factor are expressed in both immature and mature dental pulps. VEGFA and its receptors are expressed significantly higher in mature apex teeth than immature apex teeth.

Dentin Growth after Direct Pulp Capping with the Different Fractions of Plasma Rich in Growth Factors (PRGF) vs. MTA: Experimental Study in Animal Model.

BACKGROUND: This study aimed to evaluate the area of dentin growth in rabbit incisors after pulp capping with plasma rich in growth factors (PRGF) compared with mineral trioxide aggregate (MTA) by fluorescence. METHODS: twenty-seven upper and lower incisors of rabbits were divided into 4 groups: poor PRGF (F1) (n = 9 teeth), rich PRGF (F2) (n = 8 teeth), ProRoot MTA (positive control, n = 5 teeth), and untreated (NC) (negative control, n = 5). Fluorochrome markers were injected 24 h before surgery and the day before euthanasia, 28 days after the vital pulp therapy (VPT). Two transverse cuts were performed to every tooth: the first cut (A), 1 mm incisal to the gingival margin, and the second cut (B), 5 mm apical to the first cut. The sections were assessed with histomorphometric evaluation by fluorescence microscopy, comparing the dentin area between fluorescence marks and the total mineralized area. RESULTS: The higher percentage of dentin growth was observed in the F2 group (B = 63.25%, A = 36.52%), followed by F1 (B = 57.63%, A = 30,12%) and MTA (B = 38.64%, A = 15.74%). The group with lowest percentage of dentin growth was the NC group (B = 29.22%, A = 7.82%). Significant difference (p < 0.05) was found between F2 group and MTA, also statistically significant difference has been observed comparing dentin growth areas of NC group with F1 and F2 groups. CONCLUSIONS: The application of PRGF rich and poor fraction as a pulp capping material stimulated dentin formation more intensively than MTA and NC.

Regenerative endodontic procedure combined with apical surgery of a necrotic permanent incisor with extensive periapical lesion using plasma rich in growth factors (PRGF): A Case report with 6 years post-op evaluation using CBCT.

BACKGROUND: The aim of this case report is to describe the step-by step and outcomes of a treatment approach which simultaneously combines a Regenerative Endodontic Procedure (REP) and apical surgery using PRGF as treatment of a post-traumatic necrotic permanent central incisor with extensive periapical lesion and undeveloped apex in a 16 years-old patient. CASE DESCRIPTION: A 16 years-old patient with an extensive periapical lesion in the maxillary central incisor was treated with a combination of REP and periapical surgery in the same visit. A Bi- antibiotic paste (BAP) was used to priorly disinfect the canal, which was posteriorly sealed with MTA placed over a PRGF clot at the same time that the periapical lesion was surgically debrided, removed and grafted, The radiographic and CBCT follow-up results showed a complete healing of the radiolucent lesion, which was replaced with bone-like tissue in two years and well preserved until six years later. PRACTICAL IMPLICATIONS: A combined approach of a Regenerative Endodontic Procedure and apical surgery using PRGF may be a good treatment modality in cases of extensive periapical lesions in necrotic teeth with open apexes. PRGF has shown to act as an ideal autologous matrix because it is stable, provides growth factors and bioactive molecules, and stimulates collagen production, angiogenesis, and cell differentiation. Key words:Regenerative endodontic procedure, open apex necrotic tooth, periodontal apical lesion, growth factors, apical surgery.

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 .

Three-dimensional analysis of the root canal preparation with Reciproc Blue®, WaveOne Gold® and XP EndoShaper®: a new method in vivo.

BACKGROUND: The purpose of this study was to evaluate the changes in canal volume after root canal preparation in vivo with 3 different single-file techniques (Reciproc-Blue®, WaveOne-Gold® and XP-EndoShaper®), with a new method using CBCT and 3D reconstruction. METHODS: In this prospective study, thirty human lower premolars from healthy patients were used, in which extraction was indicated for orthodontic reasons. All the teeth used were caries- and restoration-free with complete root development, without signs of periodontal disease or traumatic occlusion, and with only one straight canal (up to 25º curvature). Teeth were randomly divided into three different groups: Reciproc-Blue, WaveOne-Gold and XP-EndoShaper. CBCT scans before root canal preparation were used to create a 3D reconstruction with RHINOCEROS 5.0 software to assess the initial canal volume, and then compared with 3D reconstructions after canal preparation to measure the increase in canal volume. Student's t test for paired data were used to determine statistically significant differences between the before and after canal volumes. Anova test was used to determine statistically significant differences in the percentage of canal volume increase between the groups and Tukey's post-hoc test were used to paired comparison. RESULTS: Reciproc-Blue showed the higher increase in canal volume, followed by WaveOne-Gold and XP-EndoShaper (p = 0.003). XP-EndoShaper did not show a statistically significant increase in canal volume after root canal preparation (p = 0.06). CONCLUSION: With this model, Reciproc-Blue showed higher increase in root canal volume, followed by WaveOne-Gold, while XP-EndoShaper did not significantly increase root canal volume during preparation.

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.

Use of Platelet-rich Plasma in Endodontic Procedures in Adults: Regeneration or Repair? A Report of 3 Cases with 5 Years of Follow-up.

INTRODUCTION: Regenerative endodontic procedures (REP) are a promising alternative for necrotic immature teeth in adolescents and children, but very little evidence is available on this alternative in long-lasting necrotic teeth with open apices in adults. REPs are designed to replace damaged structures of the pulp-dentin complex, but no regeneration has been obtained in any of the cases described in necrotic immature permanent teeth with apical periodontitis with histologic results. The results are limited to periapical tissue repair with increasing root length, thickening of the root walls, and apical closure in young patients. In this series of cases, we report on the outcomes of the adjuvant use of autologous platelet-rich plasma (PRP) in endodontic therapy in adults by monitoring periapical tissue healing with periodic periapical radiographs and cone-beam computed tomographic scanning. METHODS: Three teeth with apical periodontitis and open apices in 3 different patients from 21 to 35 years-old were evaluated. An REP was performed with the adjuvant use of PRP. RESULTS: At controls, complete disappearance of the radiolucent lesions and the presence of calcified structures forming bridges occupying the pulp lumen were observed but not an ostensible thickening of root walls with a regeneration of pulp-dentin complex. CONCLUSIONS: The repair of periapical tissues with REPs of open apex teeth with apical periodontitis and in nonsurgical endodontic retreatment appears to be feasible in adults, but no regeneration was obtained in any of the present cases. The use of PRP may be a good choice as an autologous matrix because of its stability and induction; it contains growth factors and bioactive molecules like transforming growth factor beta, bone morphogenic proteins, insulinlike growth factors, and angiogenetic growth factors, which stimulate collagen production, angiogenesis, and cell differentiation. Anti-inflammatory and antibacterial properties have also been reported for this preparation, which are involved in all processes of repair.

The effect of glass ionomer and adhesive cements on substance P expression in human dental pulp

OBJECTIVES: The purpose of this study was to quantify the effect of glass ionomer and adhesive cements on SP expression in healthy human dental pulp. Study DESIGN: Forty pulp samples were obtained from healthy premolars where extraction was indicated for orthodontic reasons. In thirty of these premolars a Class V cavity preparation was performed and teeth were equally divided in three groups: Experimental Group I: Glass Ionomer cement was placed in the cavity. Experimental Group II: Adhesive Cement was placed in the cavity. Positive control group: Class V cavities only. The remaining ten healthy premolars where extracted without treatment and served as a negative control group. All pulp samples were processed and SP was measured by radioimmunoassay. RESULTS: Greater SP expression was found in the adhesive cement group, followed by the glass ionomer and the positive control groups. The lower SP values were for the negative control group. ANOVA showed statistically significant differences between groups (p < 0.0001). Tukey HSD post hoc tests showed statistically significant differences in SP expression between negative control group and the 3 other groups (p < 0.01). Differences between the cavity-only group and the two experimental groups were also statistically significant (p < 0.05 and p < 0.01 respectively). There is also a statistically significant difference between the two experimental groups (p < 0.01). CONCLUSIONS: These findings suggest that adhesive cements provoke a greater SP expression when compared with glass ionomer

The effect of glass ionomer and adhesive cements on substance P expression in human dental pulp.

OBJECTIVES: The purpose of this study was to quantify the effect of glass ionomer and adhesive cements on SP expression in healthy human dental pulp. STUDY DESIGN: Forty pulp samples were obtained from healthy premolars where extraction was indicated for orthodontic reasons. In thirty of these premolars a Class V cavity preparation was performed and teeth were equally divided in three groups: Experimental Group I: Glass Ionomer cement was placed in the cavity. Experimental Group II: Adhesive Cement was placed in the cavity. Positive control group: Class V cavities only. The remaining ten healthy premolars where extracted without treatment and served as a negative control group. All pulp samples were processed and SP was measured by radioimmunoassay. RESULTS: Greater SP expression was found in the adhesive cement group, followed by the glass ionomer and the positive control groups. The lower SP values were for the negative control group. ANOVA showed statistically significant differences between groups (p<0.0001). Tukey HSD post hoc tests showed statistically significant differences in SP expression between negative control group and the 3 other groups (p<0.01). Differences between the cavity-only group and the two experimental groups were also statistically significant (p<0.05 and p<0.01 respectively). There is also a statistically significant difference between the two experimental groups (p<0.01). CONCLUSION: These findings suggest that adhesive cements provoke a greater SP expression when compared with glass ionomer.

The effect of orthodontic forces on calcitonin gene-related peptide expression in human dental pulp.

INTRODUCTION: The purpose of this study was to quantify the effect of moderate and severe orthodontic forces on calcitonin gene-related peptide (CGRP) expression in healthy human dental pulp. METHODS: Thirty human dental pulp samples were obtained from healthy premolars in which extraction was indicated for orthodontic reasons. Before extraction, teeth were divided into 3 groups of 10 premolars each: (1) the control group: healthy premolars without application of orthodontic forces; (2) the moderate force group: a 56-g force was applied to the premolars for 24 hours; and (3) the severe force group: a 224-g force was applied to the premolars for 24 hours. All dental pulp 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 control group. The Kruskal-Wallis test showed statistically significant differences between groups (P < .0001). Least significant difference (LSD) post hoc tests showed statistically significant differences in CGRP expression between the control group and the severe force group (P < .0001) but not with the moderate force group (P = .06). Differences between the moderate and severe force groups were statistically significant (P < .0001). CONCLUSIONS: CGRP expression in human dental pulp increases when teeth are submitted to severe orthodontic forces.