Drug-induced gingival overgrowth: A clinical and histopathological report

Gingival overgrowth is a significant problem faced by periodontists and is particularly associated with the use of certain drugs such as nifedipine, a high-specificity calcium channel blocker used for the treatment and prophylaxis of certain cardiovascular diseases. Development of gingival overgrowth is characterized by increased collagen in gingival tissue. In general is asymptomatic, at times associated with spontaneous bleeding and ulceration and can promote aesthetic changes and compromise hygiene habits and mastication of the patient. The severity of the symptoms is associated with the presence of risk factors such association with other drugs. This paper aims to present a case report of a patient with generalized gingival overgrowth, with more severe characteristics in the anterior mandible induced by chronic use of nifedipine who underwent basic non-surgical periodontal treatment including supra and subgingival scaling and root planning in both jaws associated with rigorous oral hygiene instructions and surgical therapy in the anterior mandible, the most affected area, to remove the excess of gingival tissue. Nifedipine was replaced by the patient cardiologist to propanolol hydrochloride (40 mg/kg) in an attempt to minimize unwanted side effects. After 6 month follow-up, no recurrence was observed, oral hygiene had improved and the patient had clinical periodontal health and esthetic satisfaction.

Biocompatibility and biomineralization assessment of a new root canal sealer and root-end filling material

Objective: This study investigated the short-term subcutaneous tissue reaction and biomineralization ability of two epoxy-based root canal sealers containing calcium hydroxide (MBP and MBPc) and ProRoot MTA. Materials and methods: Polyethylene tubes containing the materials were implanted into the dorsal connective tissue of Wistar rats (n = 52) for 7 or 30 days; empty implanted tubes served as controls. Specimens were stained with hematoxylin-eosin and von Kossa stain or left unstained for observation under polarized light. Qualitative and quantitative evaluations of all tissue reactions were performed. One-way anova and the Kruskal-Wallis test were used for statistical analysis (P < 0.05). Results: No significant differences were observed among the groups. All three materials induced mild-to-moderate tissue reactions at 7 days, which decreased over time. Dystrophic mineralization and birefringent structures were observed only in the ProRoot MTA ® group. Conclusion: Both MBP and MBPc appear to be biocompatible but do not stimulate biomineralization. © 2012 John Wiley & Sons A/S.

Search for heavy narrow dilepton resonances in pp collisions at root s=7 TeV and root s=8 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Root system and root and stem base organic reserves of pasture Tanzania grass fertilizer with nitrogen under grazing

The goal of this study was to evaluate the concentrations of non-structural carbohydrate (NSC) and of total nitrogen (N), as well as, to evaluate the root system in Tanzania-grass pastures fertilized with doses of urea in fall, spring and summer. The experiment was conducted at the Experimental Farm of Iguatemi, Maringa, Parana, Brazil, from March 2007 to March 2008. The experimental design was complete random blocks with subplots and four repetitions. The plots showed doses of N (50, 100 e 150 kg ha(-1) of N) plus the control (no N fertilization), and the subplots the season of the year. Root samples were taken at depths of 0-10, 10-20 and 20-40 cm. Root biomass showed a trend for mass accumulation up to a dosage of 100 kg ha(-1) for all seasons evaluated. Also, about 80% of the root system of Tanzaniagrass plants was found on the 0-10 cm layer for all dosages of N. Nitrogen fertilizer above 100 kg ha(-1) may foster fast forage plant growth reducing its NSC root storage capacity although favoring NSC and total N storage at stem base. NSC and total N concentrations were highest in fall, demonstrating that its usage is greater in spring due to the weather conditions being favorable to plant growth. In the regrowth, the largest reserve of total N was at the 0-10 cm root layer and the largest NSC reserve is at stem base.

SEM Evaluation of the Interface Between Filling and Root- End Filling Materials

The aim of this ex vivo study was to evaluate, by scanning electron microscopy (SEM), the presence of gaps at the interface between filling material and three root-end filling materials. Thirty human upper molars disto-buccal roots were instrumented and filled with gutta-percha and eugenol-based sealer. The apicoectomy was performed 2mm from the apex and retrograde cavities were prepared with ultrasonic points (3mm in deep). The samples were divided into three experimental groups (n=10): Group Iwhite mineral trioxide aggregate (MTA); Group IISuper EBA; and Group IIIPortland cement. The root-end filling materials were inserted into the retocavities using a MTA carrier. After 48h, the roots were transversally sectioned in order to obtain the apical 5mm. Next, each specimen was prepared longitudinally with crescent granulation of abrasives water-wet sandpapers in order to expose the filling and root-end filling materials. Then, the specimens were subjected to slow dehydration with silica gel, mounted onto specific stubs and coated with paladium coverage for SEM analysis of the interface between filling and root-end filling materials. The percentage of gaps at the interfacial area was calculated by using Image Tool 3.0 software. Super EBA presented the higher percentage of gaps (1.5 +/- 0.67%), whereas MTA presented the lowest values (0.33 +/- 0.20%; p=0.0004). Despite the statistical differences observed between Super EBA and MTA, all the root-end filling materials presented great adaptation to the filling material, presenting small amount of gaps. SCANNING 36:252-257, 2014. (c) 2013 Wiley Periodicals, Inc.

Effect of platele-rich plasma on healing of class III furcation defects treated with autogenous bone grafting and guided tissue regeneration: a histomorphometric sutdy in dogs

Objective: The purpose of this study was to evaluate the effects of the platelet-rich plasma (PRP) when used in combination with autogenous bone graft and bioabsorbable membrane (Resolut® ) in the treatment of Class  III furcation defects in dogs. Material and method: Class III furcation defects (5 mm in height and in depth) were surgically created in the mandibular third premolars of five mongrel dogs. After nine weeks, the lesions were treated with scaling and root planning and each defect received one of the following treatments: autogenous bone graft + membrane (group C) or PRP + autogenous bone graft + membrane (group T). After a healing period of 90 days, the animals were sacrificed. Routine histological processing and staining with hematoxilyn and eosin and Masson trichrome were performed and a histomorphometric analysis determined the effect of the treatments on periodontal tissue regereneration. Data were analyzed by Hotelling’s T-squared (p < 0.05). Result: No statistically significant difference between C and T groups was observed by the histomorphometric analysis of the furcation area. Both treatment groups demonstrated similar regenerative results with the furcation defects partially filled and periodontal regeneration limited to the experimental notches of the lesions. (p > 0.05). Conclusion: According to the present results, PRP does not enhance the periodontal regeneration in class III furcation defects treated with autogenous bone graft and bioabsorbable membrane.

Improvement of an anterior infrabone defect using combined periodontal and orthodontic therapy: a 6-year follow-up case report

Extensive intraosseous lesions represent a clinical challenge for the periodontist. Sites with bone defects have been shown to be at higher risk of periodontitis progression in patients who had not received periodontal therapy. Thus, the aim of this case report was to describe a novel approach for the treatment of 1-walled intraosseous defect by combining nonsurgical periodontal therapy and orthodontic movement toward the bone defect, avoiding regenerative and surgical procedures. A 47-year-old woman underwent the proposed procedures for the treatment of her left central incisor with 9 mm probing depth and 1-walled intraosseous defect in its mesial aspect. Initially, basic periodontal therapy with scaling and root planning was accomplished. Two months later, an orthodontic treatment was planned to eliminate the intraosseous lesion and to improve the interproximal papillary area. Orthodontic root movement toward the osseous defect was performed for 13 months with light forces. After 6 years postoperative it was concluded that combined basic periodontal therapy and orthodontic movement was capable of eliminating the intraosseous defect and improve the esthetics in the interproximal papillary area between the central incisors.

Effect of platelet-rich plasma on healing of class III furcation defects treated with autogenous bone grafting and guided tissue regeneration: a histomorphometric study in dogs

The purpose of this study was to evaluate the effects of the platelet-rich plasma (PRP) when used in combination with autogenous bone graft and bioabsorbable membrane (Resolut® ) in the treatment of Class  III furcation defects in dogs. Material and method: Class III furcation defects (5 mm in height and in depth) were surgically created in the mandibular third premolars of five mongrel dogs. After nine weeks, the lesions were treated with scaling and root planning and each defect received one of the following treatments: autogenous bone graft + membrane (group C) or PRP + autogenous bone graft + membrane (group T). After a healing period of 90 days, the animals were sacrificed. Routine histological processing and staining with hematoxilyn and eosin and Masson trichrome were performed and a histomorphometric analysis determined the effect of the treatments on periodontal tissue regereneration. Data were analyzed by Hotelling’s T-squared (p < 0.05). Result: No statistically significant difference between C and T groups was observed by the histomorphometric analysis of the furcation area. Both treatment groups demonstrated similar regenerative results with the furcation defects partially filled and periodontal regeneration limited to the experimental notches of the lesions. (p > 0.05). Conclusion: According to the present results, PRP does not enhance the periodontal regeneration in class III furcation defects treated with autogenous bone graft and bioabsorbable membrane.

Comparative analysis of three rotary instruments used for coronal pre-enlargement in radicular dentin thickness and root canal area of mandibular molars

Purpose: The purpose of this study was to evaluate the increase of the cervical area and dentin thickness in mesial and distal walls of the mesial canals from mandibular molars after the use of LA Axxess (LA), CP Drill (CP) and Gates-Glidden (GG) rotary instruments. Material and Methods: Sixty root canals from thirty mandibular first molar were sectioned 3 mm below the cement-enamel junction, divided in 3 groups (n = 20 root canals, each) according to rotary instrument used, and the cervical images were captured before and after pre-enlargement instrumentation. The increase of the instrumented cervical area (mm2) and the dentin removal thickness (mm), at mesial and distal walls were calculated using Image tools software, by comparison of images. Data were analyzed by ANOVA and Tukey tests (p=0.05). Results: All rotary instruments promoted thickness reduction in dentin walls. In mesial wall, all rotary instruments promoted similar thickness reduction of dentinal wall and did not differ from each other (p>0.05). In distal wall, LA Axxess instrument promoted higher dentin thickness reduction than other groups (p<0.05). The three rotary instruments promoted different increase at the instrumented cervical area (p<0.05), LA promoted the highest increase area and GG and CP presented similar results. Conclusion: LA 20/0.06 promoted the highest thickness reduction in distal wall and increase of cervical area of root canal. On the other hand, CP was the safest instrument, with lower dentin removal of distal wall and similar increased area to GG.

A microscopic analysis of the effects of root surface scaling with different power parameters of er,cr: YSGG laser

The aim of this study was to evaluate the effects of different power parameters of an Erbium, Cromium: Yttrium, Scandium, Gallium, Garnet laser (Er,Cr:YSGG laser) on the morphology, attachment of blood components (ABC), roughness, and wear on irradiated root surfaces. Sixty-five incisive bovine teeth were used in this study, 35 of which were used for the analysis of root surface morphology and ABC. The remaining 30 teeth were used for roughness and root wear analysis. The samples were randomly allocated into seven groups: G1: Er,Cr:YSGG laser, 0.5 W; G2: Er,Cr:YSGG laser, 1.0 W; G3: Er,Cr:YSGG laser, 1.5 W; G4: Er,Cr:YSGG laser, 2.0 W; G5: Er,Cr:YSGG laser, 2.5 W; G6: Er,Cr:YSGG laser, 3.0 W; G7: scaling and root planning (SRP) with manual curettes. The root surfaces irradiated by Er,Cr:YSGG at 1.0 W and scaling with manual curettes presented the highest degrees of ABC. The samples irradiated by the Er,Cr:YSGG laser were rougher than the samples treated by the manual curette, and increasing the laser power parameters caused more root wear and greater roughness on the root surface. The Er,Cr:YSGG laser is safe to use for periodontal treatment, but it is not appropriate to use irradiation greater than 1.0 W for this purpose. Microsc. Res. Tech. 78:529–535, 2015. © 2015 Wiley Periodicals, Inc.

The smear layer created by scaling and root planing is physiologically eliminated in a biphasic process

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Influence of Insertion Techniques for Resin Cement and Mechanical Cycling on the Bond Strength Between Fiber Posts and Root Dentin

Purpose: To evaluate the effect of the insertion technique for resin cement and mechanical cycling on the bond strength between fiber posts and root dentin.Materials and Methods: Sixty-four single-rooted bovine teeth were endodontically prepared to receive glass-fiber posts. The insertion of cement into the root canal was performed using one of the following techniques: POS, insertion with the post; LEN, the use of a lentulo-type drill; EXP, insertion with a straight-tip explorer; or CEN, the use of a Centrix syringe. Half of the specimens were mechanically cycled. All specimens were sectioned into slices of 1.8 mm for the push-out test and 0.5 mm for analysis of the cement layer quality.Results: The insertion technique affected the interaction between factors (bond strength and mechanical cycling; p < 0.0001). Insertion of the Centrix syringe after mechanical cycling showed the highest bond values (13.6 +/- 3.2 MPa). Group-to-group comparisons for baseline and cycled conditions indicated that mechanical cycling significantly influenced the bond strength (p < 0.0001) of the POS and CEN groups. The quality of the cement layer did not differ between the techniques when evaluated in the middle (p = 0.0612) and cervical (p = 0.1119) regions, but did differ in the apical region (p = 0.0097), where the CEN group had better layer quality for the two conditions tested (baseline and cycled).Conclusion: The use of the Centrix syringe improved the homogeneity of the cement layer, reducing the defects in the layer and increasing adhesive strength values to dentin, even after mechanical cycling.

Healing process of dogs' pulpless teeth after apicoectomy and root canal filling at different levels

Dogs' teeth with infected root canals, were submitted to apicoectomy and the root canals were filled flush or 2 mm short. In a third group the canals were left unfilled and only the access openings were closed. One hundred and eighty days after the treatment, the animals were killed and the specimens prepared for histological analysis. Repair was not observed in the teeth with unfilled root canals. The healing observed in the teeth with root canals filled flush was less complete than the healing observed when the root canals were filled 2 mm short.

Multi-step adhesive cementation versus one-step adhesive cementation: push-out bond strength between fiber post and root dentin before and after mechanical cycling

This study evaluated the effects of mechanical cycling on resin push-out bond strength to root dentin, using two strategies for fiber post cementation. Forty bovine roots were embedded in acrylic resin after root canal preparation using a custom drill of the fiber post system. The fiber posts were cemented into root canals using two different strategies (N = 20): a conventional adhesive approach using a three-step etch-and-rinse adhesive system combined with a conventional resin cement (ScotchBond Multi Purpose Plus + RelyX ARC ), or a simplified adhesive approach using a self-adhesive resin cement (RelyX U100). The core was built up with composite resin and half of the specimens from each cementation strategy were submitted to mechanical cycling (45 degree angle; 37 degrees C; 88 N; 4 Hz; 700,000 cycles). Each specimen was cross-sectioned and the disk specimens were pushed-out. The means from every group (n = 10) were statistically analyzed using a two-way ANOVA and a Tukey test (P = 0.05). The cementation strategy affected the push-out results (P < 0.001), while mechanical cycling did not (P = 0.3716). The simplified approach (a self-adhesive resin cement) had better bond performance despite the conditioning. The self-adhesive resin cement appears to be a good option for post cementation. Further trials are needed to confirm these results.

Cadmium stress antioxidant responses and root-to-shoot communication in grafted tomato plants

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)