Manuel Marques Ferreira

Quantitative scintigraphic analysis of pulp revascularization in autotransplanted teeth in dogs

OBJECTIVE The purpose of this study was to evaluate the pulpal changes associated with autogenous single-rooted immature tooth transplantation in dogs, using either one, or two-stage surgical techniques. METHODS Teeth from 3 beagle dogs, 5 months old, were extracted and transplanted to mechanically prepared recipient sockets. Group (A), where the teeth were transplanted using a one-stage method to recipient beds prepared immediately before transplantation. Group (B), where the teeth were transplanted using a two-stage method in which the recipient beds were prepared and left to heal for 7 days before transplantation. Clinical examinations were done every week during 9 weeks. After 9 weeks, the animals were injected with ⁹⁹(m)Technetium hydroxylmethylene diphosphonate (⁹⁹(m)Tc-HMDP) and 3h after injection, a whole body scintigraphic acquisition was performed. After scintigraphic acquisition the animals were euthanized and the teeth extracted and its radioactivity counted in a well counter calibrated to ⁹⁹(m)Tc. With the data obtained, the percentage of activity injected was calculated for each tooth. The data for each group of teeth were evaluated and analyzed using the Mann-Whitney test (p=0.05). RESULTS All the transplanted teeth in both groups survived. No statistically significant difference was found in the absorption of the ⁹⁹(m)Tc-HMDP, between the treatment groups (p=0.464) and between them and the control group (Group A vs. control p=0.713 and Group B vs. control p=0.157). CONCLUSIONS This study demonstrated that there was no difference between the two surgical techniques in terms of the pulp revascularization in transplanted teeth.

Bisphosphonate-related osteonecrosis of the jaw: specificities

Bisphosphonate-related osteonecrosis of the jaws (BRONJ) is a severe complication that has recently emerged in patients treated with intravenous bisphosphonates for malignant diseases. This complication usually presents after a minor local trauma during a dental treatment. Several etiopathogenic mechanisms of this pathological condition have been proposed, but no model can explain all morphological changes observed at the macroscopic and microscopic level. BRONJ is likely to be related to direct toxicity in the bone and soft tissue cells, due to nitrogen-containing bisphosphonates. This review elucidates the clinical indications and mechanism of action of bisphosphonates, reports some clinical diagnostic criteria for BRONJ, describe the histopathological criteria for BRONJ diagnosis, the potential triggering pathways and the available treatment strategies.

Effects on gastric mucosa induced by dental bleaching – an experimental study with 6% hydrogen peroxide in rats

The value of aesthetic dentistry has precipitated several developments in the investigation of dental materials related to this field. The free marketing of these products is a problem and it is subject to various interpretations regarding its legality. There are several techniques for tooth whitening, the most used one being the external bleaching. It is the later version of such technique that poses the greatest danger of ingesting the product. The present study analysed the systemic effect of these products when they are swallowed. Objective This experimental study aimed to observe the effects of a tooth whitening product, whose active agent is 6% hydrogen peroxide, on the gastric mucosa of healthy and non-tumour gastric pathology animals. Material and Methods Fifty Wistar-Han rats were used and then distributed into 5 groups, one for control and four test groups in which the bleaching product was administered in animals with and without non-tumour gastric pathology (induced by the administration of 1 sample of 50% ethanol and 5% of drinking water during 6 days) at different times of study by gavage. There was a decrease in body weight in animals of groups handled during the study period, which was most pronounced in IV and VA groups. Changes in spleen weight relative to body weight revealed no statistically significant changes. An analysis of the frequency was performed on the results of macroscopic observation of the gastric mucosa. Results The gastric mucosa revealed lesions in all manipulated groups, being more frequent in groups III and IV. It appears that there is a synergism when using hydrogen peroxide and 50% ethanol in the same group. Conclusion Therefore, it seems that there are some signs of toxicity 3 to 4 days after administration of 6% hydrogen peroxide. The prescription of these therapies must be controlled by the clinician and the risks must be minimized.

Therapies for White Spot Lesions—A Systematic Review

Introduction The first sign of dental caries is denoted by white spot lesions (WSLs) which can be defined as a demineralization of the enamel surface and subsurface, although these lesions can be reversed and do not form cavities. The aim of this systematic review was investigate which remineralization agents are effective for the treatment of WSLs. Materials and Methods For this systematic review a literature search was conducted on Pubmed, Cochrane Library and ScienceDirect. Results The initial search resulted in 273 references. After elimination of duplicate articles, 236 references remained. After reading titles and abstracts, all non‐relevant results were excluded, resulting in 45 potentially relevant studies. After reading the full text, 13 references were included. Conclusion More studies are required for scientific evidence in order to reach a conclusion of the most suitable therapeutic method for the treatment of surface and subsurface demineralization of the enamel.

Evaluation of dentin formed in autogenous tooth transplantation in the dog: a comparison between one- and two-stage surgical techniques

This study was designed to compare the thickness of dentin formed associated with autogenous tooth transplantation in dogs, using either one- or two-stage surgical techniques. The study consisted of three Beagles, older than 5 months, in which six incisors and six premolars were transplanted to mechanically prepared recipient sockets. One group was transplanted using a one-stage method to recipient beds prepared immediately before transplantation. The second groups of teeth were transplanted using a two-stage method in which the recipient beds were prepared and left to heal for 7 days before transplantation. Dogs were injected with xylenol orange, calcein and oxytetracycline at 2 days before, 3 and 9 weeks after transplantation, respectively, for vital staining. Clinical examinations were carried out every week, and the animals were euthanized 9 weeks later. The jaws were resected, fixed in formaldehyde and embedded in resin. Undemineralized sections were cut and examined by fluorescent microscopy. The thickness of dentin formed in the third week after transplantation and 9 weeks was evaluated by undertaking histomorphometric analysis and analysed using the Mann-Whitney U test (P = 0.05). All the transplanted teeth in both groups survived, and the dentin was formed. No statistically significant difference was found in the thickness of dentin formed in the third week and formed in the third to ninth week between the treatment groups (P = 0.999 and P = 0.998, respectively). This study demonstrated that there was no difference between the two surgical techniques in terms of the thickness of dentin formed in transplanted teeth.

Reabsorção Radicular Interna

Resumo As reabsorcoes radiculares internas constituem situacoes clinicas raras, nos dentes permanentes. Sao caracterizadas por um alargamento localizado no espaco pulpar, de forma oval. A reabsorcao radicular externa, que e muito mais comum, e com frequencia confundida com a interna. Para evitar erros de tratamento, e imperioso realizar um diagnostico diferencial correcto.

Dental caries and bacterial load in saliva and dental biofilm of type 1 diabetics on continuous subcutaneous insulin infusion

Abstract Objectives Since most of the studies evaluates diabetics on multiple daily injections therapy and continuous subcutaneous insulin infusion may help gain better metabolic control and prevent complications, the objective of this study was to evaluate the prevalence of dental caries, the unstimulated salivary flow rate and the total bacteria load, Streptococcus spp. levels and Lactobacillus spp. levels in saliva and supragingival dental biofilm of type 1 diabetics on insulin pump. Material and Methods Sixty patients with type 1 diabetes on insulin pump and 60 nondiabetic individuals were included. The dental caries evaluation was performed using ICDAS and the oral hygiene was assessed according to Greene and Vermillion Simplified Oral Hygiene Index. Unstimulated saliva and supragingival dental biofilm were collected. Total bacteria, Streptococcus spp. and Lactobacillus spp. was quantified by qPCR. Results Patients with type 1 diabetes had a higher prevalence of dental caries and filled and missing teeth when compared with the control group. These patients were associated with more risk factors for the development of dental caries, namely a lower unstimulated salivary flow rate and a higher bacterial load in saliva and dental biofilm. Conclusion Some risk factors related to dental caries were associated with type 1 diabetics. An early diagnosis combined with the evaluation of the risk profile of the diabetic patient is imperative, allowing the dental caries to be analyzed through a perspective of prevention and the patient to be integrated into an individualized oral health program.

Ebstein's anomaly in children: A single-center study in Angola

INTRODUCTION AND OBJECTIVE Ebsteins anomaly is a rare complex congenital heart defect of the tricuspid valve. We aimed to describe the frequency, clinical profile, and early and short-term post-operative results in patients under the age of 18 years operated for this anomaly in a tertiary center in Angola. METHODS A retrospective cross-sectional study was conducted over a period of 37 months. We analyzed all patients diagnosed with congenital heart defects. RESULTS Of the 1362 patients studied, eight (0.6%) had Ebsteins anomaly; six patients (75%) were female. Mean age was 69±59 months. Five patients were in NYHA functional class III or IV. Mean cardiothoracic index was 0.72. Seven patients (87.5%) had severe tricuspid regurgitation and five (62.5%) had another associated congenital heart defect. All patients were operated: two had complications and one (12.5%) died in the early post-operative period. The mean follow-up time was 1.22±0.6 years, and mortality during follow-up was 12.5% (n=1). At the end of the study, of the five patients in whom cone reconstruction was performed, four (80%) were in functional class I. Mean cardiothoracic index decreased to 0.64. Three patients had mild and two had moderate tricuspid regurgitation. The patient who underwent cone reconstruction and a Glenn procedure was in functional class I. CONCLUSION The frequency of Ebsteins anomaly was similar to that in other centers. Cone reconstruction was viable in the majority of patients, with good early and short-term results.

Roughness and microhardness of composites after different bleaching techniques

Background The aim of this study was to evaluate the roughness and microhardness of SonicFill™ (Kerr), and compare it with Filtek™ Supreme XTE (3M ESPE) after 2 bleaching regimens. Methods Sixty cylindrical specimens (10 × 2 mm) of each of the 2 composites were prepared and divided into 6 groups (n = 20): groups 1, 2: no treatment; groups 3, 4: 10% carbamide peroxide (CP); and groups 5, 6: 35% hydrogen peroxide (HP) plus LED. After treatments, specimens were thermocycled (500 cycles, 5°C/55°C, dwell time 30 minutes). A mechanical roughness tester was employed to measure the surface roughness parameters and the Vickers test to measure microhardness. One-way ANOVA, Tukey and Bonferroni methods with a significance level of 5% were used for the statistical analysis. Results For SonicFill™, there was no statistically significant difference in microhardness between the control group (no. 1) and the bleached groups (nos. 3, 5), but there was difference between CP and HP treatments; for Filtek™ Supreme XTE, there was no significant difference in microhardness among all groups. There was no significant difference in average roughness (Ra) and the root mean square of the roughness (Rq) among all groups. The mean roughness depth (Rz) parameter showed no statistically significant differences among all groups for SonicFill™, but in Filtek™ Supreme XTE, there was a significant increase between control and bleaching treatments; roughness skewness (Rsk) showed no statistically significant differences among all groups for SonicFill™ and Filtek™ Supreme XTE, except for nos. 2 and 4, where the Rsk increased with CP. Conclusions The microhardness of Filtek™ Supreme XTE is less affected by bleaching than that of SonicFill™. Both bleaching treatments affect Rz in Filtek™ Supreme XTE in contrast to SonicFill™, but only the CP treatment affects the Rsk of Filtek™ Supreme XTE, with no significant effect of SonicFill™.

The effect of Emdogain gel on periodontal regeneration in autogenous transplanted dog's teeth

AIM The aim of this study was to assess the enamel matrix derivative (EMD) as biomaterial used in autogenous tooth transplantation. MATERIAL AND METHODS The study consisted of 3 beagle dogs, 5 months old, in which six incisors and six premolars were transplanted to mechanically prepared recipient alveolar sockets. One group of teeth was transplanted to a recipient bed, with EMD in the root surface. The second groups of teeth were transplanted using saline solution in the root surface. Every week, clinical examinations were done. Nine weeks later, the animals were killed and the specimens decalcified and prepared for histological and imunohistochemical analysis. Periodontal healing was evaluated by undertaking histomorphometric investigation and analyzed using the Mann- Whitney test (P = 0.05). RESULTS In both groups, all the transplanted teeth survived. Between the experimental groups, there was statistically significant difference in the complete healing (P = 0.004). There was statistically significant difference between the treatment group in the occurrence of inflammatory root resorption (P = 0.015) and the occurrence of replacement root resorption (P = 0.041). CONCLUSIONS Emdogain gel used on the surface of transplanted teeth improves the occurrence of complete healing and reduces root resorption.