Christine Men Martins

Hypertension Undermines Mineralization-inducing Capacity of and Tissue Response to Mineral Trioxide Aggregate Endodontic Cement

INTRODUCTION This study evaluated the effect of hypertension on tissue response to and mineralization capacity of white and gray mineral trioxide aggregate (MTA) (Angelus Industry Ontological Products, Londrina, Brazil), an endodontic reparative cement. METHODS Polyethylene tubes containing gray MTA, white MTA, or intermediate restorative material (positive control) or an empty tube (negative control) were implanted into the dorsal connective tissue of spontaneous hypertensive and Wistar rats (n = 12 each). Six rats in each group were sacrificed after 7 days, and the remainder after 30 days. Tubes with surrounding tissue were removed, and a histologic analysis was performed using hematoxylin-eosin and von Kossa staining and examination by polarized light microscopy. RESULTS The inflammatory response to all materials was greater in hypertensive compared with normotensive rats (P < .05). Positive von Kossa staining and birefringent structures in polarized light were observed for both gray and white MTA (P > .05), but these were more pronounced in normotensive rats (P < .05). Necrotic areas with positive von Kossa staining were observed for intermediate restorative material. CONCLUSIONS Hypertension undermines tissue repair and mineralization, which can negatively affect treatment outcome. Nonetheless, mineralization in response to MTA was observed even under hypertensive conditions.

Evaluation of photodynamic therapy on fibroblast viability and cytokine production

BACKGROUND The aim of this study was to evaluate the effects of photodynamic therapy with curcumin (PDT) comparatively to 5% sodium hypochlorite (NaOCl) and saline solution on cell viability and cytokine (IL-1β and IL-6) production by mouse fibroblasts. METHODS Sixty seconds of pre-irradiation time with curcumin 500mg/L and Led wavelength (λ) 480nm, 72Jcm(2), for 300s was used for PDT. Solutions were diluted in culture medium DMEM (1×10(4) cells) and placed into 24-well cell culture plates with mouse fibroblasts L-929. Culture medium was used as control. After 6, 24 and 48h, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay (MTT) was used to evaluate the cell viability and the supernatant was collected for cytokine evaluation using enzyme-linked immunosorbent assay (ELISA). The results were statistically analyzed by ANOVA and BonFerroni correction (p<0.05) for MTT and Kruskal-Wallis test and Dunn (p<0.05) for ELISA. RESULTS PDT and saline solution presented low cytotoxic effect similar to the control group (p>0.05) while 5% NaOCl was more cytotoxic than PDT (p<0.05) in all periods of time. All materials similarly expressed IL-1β and IL-6 regardless to the experimental period (p<0.05). CONCLUSIONS PDT with curcumin was not cytotoxic to L929 fibroblasts differently from 5% NaOCl. In all groups occurred similar expression of IL-1β and IL-6.

Dragon's Blood Sap (Croton Lechleri) As Storage Medium For Avulsed Teeth: In Vitro Study Of Cell Viability

Tooth replantation success depends on the condition of cementum periodontal ligament after tooth avulsion; which is influenced by storage medium. The dragons blood (Croton lechleri) sap has been suggested as a promising medium because it supports collagen formation and exhibits healing, anti-inflammatory and antimicrobial properties. Thus, the aim of this study was to evaluate the efficacy of dragons blood sap as a storage medium for avulsed teeth through evaluation of functional and metabolic cell viability. This in vitro study compared the efficacy of different storage media to maintain the viability of human peripheral blood mononuclear and periodontal ligament cells. A 10% dragons blood sap was tested while PBS was selected as its control. Ultra pasteurized whole milk was used for comparison as a commonly used storage medium. DMEM and distilled water were the positive and negative controls, respectively. The viability was assessed through trypan blue exclusion test and colorimetric MTT assay after 1, 3, 6, 10 and 24 h of incubation. The dragons blood sap showed promising results due to its considerable maintenance of cell viability. For trypan blue test, the dragons blood sap was similar to milk (p<0.05) and both presented the highest viability values. For MTT, the dragons blood sap showed better results than all storage media, even better than milk (p<0.05). It was concluded that the dragons blood sap was as effective as milk, the gold standard for storage medium. The experimental sap preserved the membrane of all cells and the functional viability of periodontal ligament cells.

Systemic bone marker expression induced by grey and white mineral trioxide aggregate in normal and diabetic conditions

AIM To investigate the relationship between diabetes mellitus and local/systemic effects of both grey and white mineral trioxide aggregate (MTA) Angelus on bone marker expression. METHODOLOGY Wistar rats were divided into two groups: healthy and diabetic (Alloxan induced), which were further divided into three subgroups (control, GMTA Angelus and WMTA Angelus). Polyethylene tubes filled with MTA materials or empty tubes were implanted in dorsal connective tissue. On days 7 and 30, blood samples were collected for calcium, phosphorus and ALP measurement. The animals were euthanized; implanted tubes were removed and processed for immunohistochemical analysis of osteocalcin (OCN) and osteopontin (OPN). Kruskal-Wallis followed by Dunns multiple comparison test was performed for nonparametric data, and anova followed by Tukeys test for parametric data. RESULTS No difference in systemic serum calcium levels between both groups was observed. On day 7, serum phosphorus levels within the WMTA healthy group were higher than that of the diabetic group. On day 30, healthy rats exhibited lower phosphorus levels than diabetic ones. At both time points, the diabetic group was associated with more ALP activity than the healthy group. Immunohistochemical analyses of the healthy group revealed OCN- and OPN-positive cells in the presence of both MTA materials. However, under diabetic conditions, both OCN and OPN were absent. CONCLUSION Both MTA materials were associated with an increase in serum calcium, phosphorus and ALP, suggesting a potential systemic effect, along with triggered differentiation of OCN- and OPN-positive cells. Moreover, in diabetic conditions, an inhibitory effect on MTA-induced differentiation of OCN- and OPN-positive cells was detected.

Relationship between hypertension and periapical lesion: an in vitro and in vivo study

The aim of this study was to compare potential aspects of periapical lesion formation in hypertensive and normotensive conditions using hypertensive (BPH/2J) and wild-type control (BPN/3J) mice. The mandibular first molars of both strains had their dental pulp exposed. At day 21 the mice were euthanized and right mandibular molars were used to evaluate the size and phenotype of apical periodontitis by microCT. Proteins were extracted from periapical lesion on the left side and the expressions of IL1α, IL1β and TNFα were analyzed by ELISA. Bone marrow stem cells were isolated from adult mice femurs from 2 strains and osteoclast differentiation was evaluated by tartrate-resistant acid phosphatase (TRAP) in vitro. The amount of differentiated osteoclastic cells was nearly double in hypertensive mice when compared to the normotensive strain (p < 0.03). Periapical lesion size did not differ between hypertensive and normotensive strains (p > 0.7). IL1α, IL1β and TNFα cytokines expressions were similar for both systemic conditions (p > 0.05). Despite the fact that no differences could be observed in periapical lesion size and cytokines expressions on the systemic conditions tested, hypertension showed an elevated number of osteoclast differentiation.

Aqueous Extract of Psidium cattleianum as Intracanal Medication: An In Vitro Study of Cell Viability

Psidium cattleianum extract has shown activity against oral microorganisms and anti-inflammatory activity, and also tissue biocompatibility. These characteristics aroused interest in its use as an alternative to traditional intracanal medication. The aim of this study was to evaluate the aqueous extract of P. cattleianum cytotoxicity by structural and functional cell viability, in order to use as intracanal medication. The hypothesis is that aqueous extract of P. cattleianum should be used as intracanal medications due to better cytotoxicity response than cell culture medium. Positive control used was RPMI cell culture medium and negative control was water. Cell viability was analyzed after 1 h, 3 h, 6 h, 10 h and 24 h of incubation by exclusion method with trypan blue and MTT assay, using human mononuclear cells (PBMC) and human Periodontal Ligament Cells (PDL) in culture. By trypan blue assay, both PBMC and PDL cells showed an average viability higher (p>0.05) than RPMI when the cells were maintained in aqueous extract. Distilled water showed lowest average viability (p<0.05). By MTT assay, PDL cells showed increasing viability over time when maintained in aqueous extract culture. P. cattleianum was able to maintain the structural and functional cell viability, shoeing a higher performance than positive control. Also, this extract neutralized the detrimental effect of distillated water. The results about biocompatibility assays are promising to indicate the use of aqueous extract of P. cattleianum as an alternative to traditional intracanal medications.

A method for the geometric standardization of intraoral radiographs for long‐term follow up of replanted teeth: a case report

The interpretation of the set of radiographs taken during the follow-up period after tooth replantation might pose several difficulties, especially the inability to adequately reproduce the projection geometry of the exposures. This article describes a method for the geometric standardization of intraoral radiographs using a custom-made apparatus comprising a film-holder attached to an occlusal splint for the long-term follow up of dentoalveolar trauma. The method was applied in a patient who suffered an avulsion of the maxillary central incisors and had the teeth replanted after 4 h in saline storage. Endodontic treatment started 7 days after the trauma with changes of a calcium hydroxide intracanal medication every 15 days in the first 2 months and thereafter at 30-day intervals for 8 months. Root canal filling was carried out after this period. The radiographic exposures taken at the follow-up visits were standardized to identify the possible alterations during the repair process, such as root resorptions. A maxillary arch impression was made with alginate, and the model was cast in stone for fabrication of an acetate occlusal splint. The custom-made apparatus used for standardization of the radiographic exposures was fabricated by fixing a Rinn X-C-P film-holder and a 5-mm-long piece of 0.7-mm orthodontic wire to the occlusal splint with autopolymerized acrylic resin. Radiographs were taken at 4-month intervals, starting 10 months after replantation up to 76 months. The images were digitized and analysed using the Digora system. The length of the central incisors was determined to verify the reproduction of the projection geometry of the exposures and the orthodontic wire served to assess accuracy during length estimations in the radiographs. The method described in this article for geometric standardization of intraoral radiographs provided a consistent reproduction of the geometric exposure parameters, being indicated for use in the radiographic follow up of cases of dentoalveolar trauma.