Sterile Cotton Pellet Research Articles

Anti-Inflammatory Activity of Silibinin in Animal Models of Chronic Inflammation

Attenuation of the chronic inflammatory response is a beneficial strategy to combat several human diseases. Traditional medicine offers many plant extracts and pure natural compounds as treatment options of a wide variety of disorders including acute and chronic inflammation. The present study was designed to evaluate the anti-inflammatory effect of silibinin in experimental animal models of chronic and granulomatous inflammations. Forty-eight rats were used to induce chronic inflammation in the hind paw with formalin and granulomatous inflammation with sterile cotton pellets. The anti-inflammatory activity of silibinin (300 mg/kg, P.O) was evaluated in the two models, and compared with that produced by dexamethasone (1 mg/kg, P.O). Silibinin decreased significantly the formation of exudate and granulation tissue compared with the vehicle, but still significantly lower than that produced by dexamethasone. In conclusion, our data suggest that silibinin inhibits the production of edema and granulation tissue in experimental animal models of chronic inflammation, and could be a potential choice for the treatment of chronic inflammatory disorders.

Anti-inflammatory activity of four fractions of ethanolic extract of Crotalaria burhia Buch.-Ham. root in rats

Background: Roots of medicinal plants are common ingredients in many folk and herbal medicines system to treat inflammation. The detailed study on C. burhia root was lacking to support their anti-inflammatory potential. Henceforth, present investigation was carried out to establish scientific basis for the traditional uses of Crotalaria buriha root as anti-inflammatory agent. Aims & Objective: The present study was aimed to evaluate anti-inflammatory activity of four fractions of ethanolic extract of Crotalaria burhia Buch.-Ham. root in Wistar albino rats. Materials and Methods: Anti-inflammatory activity of four fractions of ethanolic extract of Crotalaria burhia root (EtCB) was evaluated by Carrageenan induced paw edema and cotton pellets induced granuloma in rats. Animals were divided into eight groups (n=6), in which two control groups (25% DMSO and ddH2O), two groups treated with anti-inflammatory drugs (Indomethacin: 10 mg/kg and Diclofenac: 25 mg/kg of body weight) and four fractions treated groups [Hexane (300 mg/kg of bodyweight in 25% DMSO), chloroform (300 mg/kg body weight in 25% DMSO), ethyl acetate (300 mg/kg body weight in 25% DMSO) and aqueous (300 mg/kg of bodyweight in ddH2O)] were treated with oral intubations. Acute anti-inflammatory response was evaluated by measuring paw volume at different time intervals after treatment of test and standard drug. Chronic anti-inflammatory response was evaluated after administration of test and standard treatment for seven consecutive days. On day eighth, four sterile cotton pellets (50 mg) were implanted subcutaneously in the dorsal region of the rats. On the day 16th, the rats were sacrificed and the cotton pellets with granulomatous tissue were taken out, fresh and dry pellets were weighed. Liver tissues was also excised and stored in 0.9% saline at - 20 ◦C for biochemical analysis. Results: In acute and chronic anti-inflammatory activity hexane (HF), chloroform (CF), ethyl acetate (EAF) and aqueous (AF) of EtCB were shown significant (p

In vivo anti-inflammatory activity of Garcinia indica fruit rind (Kokum) in rats

The aqueous extract of Garcinia indica fruit rind (GIE) was studied for anti-inflammatory activity in carrageenan induced paw edema and cotton pellet induced granuloma in rats. Wistar rats were orally administered GIE (400 mg/kg and 800 mg/kg) and the standard drug diclofenac sodium (10 mg/kg) 60 min prior to a subcutaneous injection of carrageenan (0.1 ml of 1% w/v) into their right hind paws to produce edema. The paw volumes were measured at various time intervals to assess the effect of drug treatment. In the granuloma model, 4 sterile cotton pellets were implanted in the ventral region in each rat. GIE (400 mg/kg and 800 mg/kg) and the standard drug diclofenac sodium (10 mg/kg) were administered orally for 8 days to the pellet implanted rats. The granuloma tissue formation was calculated from the dissected pellets and the activities of the marker enzymes AST, ALT and ALP were assayed from the serum. A significant reduction in paw edema and cotton pellet granuloma was observed with GIE treatment when compared with the carrageenan treated and cotton pellet implanted animals respectively. GIE treatment significantly attenuated the AST, ALT & ALP activities elevated by foreign body granulomas provoked in rats by the subcutaneous implantation of cotton pellets. It may be concluded that GIE possesses anti-inflammatory activity which may be due to an underlying antioxidant activity and/ or lysosomal membrane stabilization by virtue of its phenolic constituents.

Multilayered structure based on poly(N,N-dimethyl-acrylamide-co-3,9-divinyl-2,4,8,10-tetraoxaspiro (5.5) undecane) prepared in a multiphase gelation process

The study is devoted to the preparation of a multi-membrane gel system based on poly(N,N-dimethyl-acrylamide-co-3,9-divinyl-2,4,8,10-tetraoxaspiro (5.5) undecane) copolymer. The complex supra-structure was realized by layer by layer deposition technique, from the gel-core to the periphery by crosslinking poly(N,N-dimethyl-acrylamide-co-3,9-divinyl-2,4,8,10-tetraoxaspiro (5.5) undecane) (P(DMA-co-U)) with N,N'-methylene-bis-acrylamide and using as well β-cyclodextrin with double purpose as compound for constructing further the edge of the interfacial supramolecular assemblies and to improve the host-guest complexation of further bioactive compounds. Basic copolymer has dual thermo- and pH sensitive character. The multi-membrane 'onion-like' gel system was tested as matrix for embedding Norfloxacin. Hematologic, biochemical, immunologic studies used to determine the biocompatibility of multi-membrane gel structures loaded with drug that directly contact living tissue provided a reasonable assessment of safety as implants. Histopathologic exams did not reveal any disturbances of the normal liver architecture in animals with multi-membrane gel system containing Norfloxacin compared to control group with sterile cotton pellets implant. Good biocompatibility for the implants based on multi-membrane gel structures loaded with drug were achieved from the in vivo tests these suggesting that biomaterials may be suitable for in vivo use as a local drug delivery system.

Post-operative Pain Analysis between Single Visit and Two Visit Root Canal Treatments using Visual Analogue Scale: An In Vivo Study

The purpose of this clinical study was to evaluate post-operative pain, after root canal therapy, performed in one appointment versus two appointment using calcium hydroxide intracanal medicament. Study design: In this in-vivo study, 60 patients requiring root canal therapy on permanent 1st molars were included. Patients were randomly divided into two experimental and one control group. Group1: One visit therapy (n=20) Group2: Two visit therapy with 1 week of calcium hydroxide dressing (n=20) Group3(Control): Two visit therapy with 1 week of sterile dry cotton pellet dressing (n=20) Materials and method : The standard protocol for all the patients included local anaesthesia, isolation & access cavity preparation, chemomechanical preparation with Rotary Protaper NiTi instruments, and irrigation with 3% sodium hypochlorite, 17% EDTA, 0.9%saline and 2% chlorhexidine. Teeth in group1 (n=20) were obturated on the same appointment using single cone technique (6% gutta percha points) and AH Plus sealer. Teeth in group 2(n=20) and group 3(n=20) were given a dressing of calcium hydroxide and dry cotton pellet respectively for a week followed by double seal with Cavit G and IRM. These teeth were obturated on the 2nd appointment using same material and techniques as in group 1. Teeth in all three groups were restored with dual cure composite resin. A modified Visual Analogue Scale was used to measure preoperative pain and postoperative pain after 6, 12, 24 & 48hrs interval. Statistical analysis was performed using an independent-sample t test. There was no statistically significant difference between groups at any of the four postoperative intervals. There was no significant difference among all the three groups studied after 12, 24hrs & 48hrs. Conclusion : Within the limitations of this in vivo study, it may be concluded that Single Visit Endodontics provides excellent results, if care in diagnosis and proper case selection is given importance. Calcium hydroxide has no relation in eliminating or reducing postoperative pain.

Anti Inflammatory Activity of Nigella sativa: A Study on Animal Model

A prospeahw study was carried out to find out dw anti-inflammatory eels of the ethanolic extract of ground seeds of Nigella saliva in inflanuned rats at the Department of Pharmacology and Therapeutics. Dhaka Medical College. during the period from January to December 2008. effect was compared among sixty tong Evan Norwegian rats with reference standard aspirin mu! hydrocortisone. Acute inflammtion uws induced by Carrafrenan inject at the sub-pplantar surface of the hind paw of rat. Ethanol extract of ground seed of Nigella aspirin, hydrocortisone and normal saline (as control) were administered to evaluate anti-inflammatory ejects. The and-inflammatory effects (acute) measured by 'inhibited oedema formation' were 43.79% by Nigella saliva. 40.52% by aspirin, 47.71% by hydrocortisone. Again chronic inflammation ~teas induced by implantation of a sterile cotton pellet in rat's groin region for 14 days and treated with Nigella saliva extract, aspirin, hydrocortisone curd normal saline. The anti-inflammatm effects (chronic) were measured by weighing cotton pellet lo evaluate 'inhibited gramdonw.formation' and were 41.42%, 27.67% and 38.58% respectively. Meweover, Nigella swim extract was administered in two different doses (250mg/kg and 500 mg/kg body weight) and significant anti-inflammatory effect was observed in' the higher dose.

Effects of Antiseptics on Pulpal Healing under Calcium Hydroxide Pulp Capping: A Pilot Study

The objective of this pilot study was to evaluate the effects of three different antiseptic materials on healing processes of direct pulp therapies with Ca(OH)(2) histopathologically. Twenty-eight upper and lower first molar teeth from 7 male Wistar rats were used in this study. Four cavities were prepared in each rat in four quadrants, and each quadrant represented different experimental groups. In Group I: 0.5% sodium hypochlorite (NaOCl); in Group II: 2% chlorhexidine digluconate (CHX); in Group III: 0.1% octenidine dihydrochloride (OCT); and in Group IV 0.9% sterile saline was applied to the exposure site with a sterile cotton pellet for 3 minutes. After hemorrhage control, the pulps were capped with hard setting Ca(OH)(2) and, finally, restored with IRM. The animals were euthanized at 21 days post-operatively. After sacrificing, routine histological procedures were performed and evaluated statistically with non-parametric Kruskal-Wallis test among the groups and two-by-two comparisons by using the Mann-Whitney U test for inflammatory response and tissue organization scores at the confidence interval of 95%. There were significant differences in inflammatory response and tissue organization scores between the groups (P<.05). Statistical evaluation of inflammatory response showed that Group IV was significantly different from Groups I, II and III separately with a higher inflammatory cell response (P<.05) whereas no significant differences were detected between the other groups in two-by-two comparisons (P>.05). Healthy coronal and radicular pulp tissue organization scores indicated that the Group I has better pulp tissue organization than Group IV and this was significantly different (P<.05) whereas no significant differences were observed between the other groups separately (P>.05). The antiseptic materials used in this study created an environment that, rather than saline solution, may affect clinical and histological success in a positive way.

Possible attenuation of nitric oxide expression in anti-inflammatory effect of Ziziphus jujuba in rat

The hydroalcoholic extract of fruits of Ziziphus jujuba (ZJ) was investigated for its anti-inflammatory effect using acute and chronic models of inflammation in rat. Wistar albino rats of either sex were employed in the present study (n = 6). Acute inflammation was induced by subplantar administration of carrageenan (1%) in rat hind paw. Chronic inflammation was induced by interscapular implantation of a sterile cotton pellet (50 mg). ZJ extract as test drug and indomethacin (10 mg/kg) as standard were used. Serum nitrite/nitrate was also estimated to determine the expression of nitric oxide. In the acute study, carrageenan (1%) administration caused marked paw edema. Pretreatment with ZJ extract exhibited marked dose-dependent attenuation in edema compared to control. In the chronic study, interscapular implantation of sterile cotton pellets caused significant granuloma formation after 7 days, serving as control. ZJ extract significantly decreased granuloma tissue formation compared to control. The serum nitrite/nitrate level was significantly increased after 7 days in the control group due to chronic inflammation, but was decreased by ZJ extract. Moreover, phytochemical studies indicated the presence of jujubosides, flavonoids and terpenes, which may produce the marked anti-inflammatory effect of ZJ fruit in acute and chronic inflammation, possibly by inhibiting nitric oxide expression. The study provides a scientific and ethnopharmacological rationale for the therapeutic use of ZJ fruit as an anti-inflammatory agent.

Effect of Calcium Hydroxide on pH Changes of the External Medium after Intracoronal Bleaching

This in vitro study evaluated the effect of calcium hydroxide on pH changes of the external medium after intracoronal bleaching. A total of 50 extracted human premolars were prepared and filled with gutta-percha and endodontic sealer. The teeth were randomly divided into five groups according to the bleaching agents employed: (a) Sterile cotton pellet with distilled water (control group); (b) sodium perborate and distilled water; (c) sodium perborate and 10% carbamide peroxide; (d) sodium perborate and 35% hydrogen peroxide; (e) 35% hydrogen peroxide. The teeth were stored in vials containing distilled water and the pH values of the medium surrounding the teeth were analyzed. After 7-day storage, the bleaching agent was removed and replaced by calcium hydroxide, and the distilled water was changed, in which the teeth were kept stored for further 14 days. Measurement of pH of the external medium (distilled water) was performed 7 days after insertion of the bleaching agents, immediately, 7 and 14 days after insertion of the calcium hydroxide. Data were submitted to statistical analysis by the two-way ANOVA and Tukey,s test. There were pH changes of the external medium at 7- day period after bleaching procedures. These results confirmed the diffusion of bleaching agents to the external medium. Calcium hydroxide increased the external medium pH and was effective for pH alkalinization after intracoronal bleaching. Intracoronal bleaching of endodontically treated teeth may cause cervical root resorption. A possible explanation for this process is the passage of bleaching agents to the periodontal tissues yielding an inflammatory process. In an attempt to keep the neutrality of the periodontal pH, the calcium hydroxide has been recommended.Results of this study showed that this material should be always used after intracoronal bleaching.

Comparison of post‐obturation pain experience following one‐visit and two‐visit root canal treatment on teeth with vital pulps: a randomized controlled trial

To compare the incidence and intensity of post-obturation pain after one- or two-visit root canal treatment (RCT) on anterior teeth with vital pulps and a single root and canal in a randomized controlled trial. One hundred patients requiring RCT on permanent anterior teeth with vital pulps preoperatively were included. The patients were assigned randomly into two groups of 50 patients each. After local anaesthesia, isolation, access and pulp extirpation, the canals of all teeth were prepared using engine-driven rotary ProTaper nickel-titanium instruments in a crown-down technique and irrigated with 2.5% NaOCl. The teeth in group 1 (n = 50) were filled with AH Plus sealer and gutta-percha using a lateral compaction technique at the first visit, whilst those in group 2 (n = 50) were medicated with a calcium hydroxide paste, a sterile dry cotton pellet and Caviton and scheduled for a second visit 7 days later. A modified verbal descriptor scale was used to measure preoperative pain and post-obturation pain at 6, 24, 48 h and 1 week after operation. Chi-square tests and independent-sample T-tests were used to compare the incidence and intensity of post-obturation pain of two groups at each interval. Eleven patients were excluded from the study as they failed to follow the scheduled revisit or their selected teeth had more than one root canal. Data were obtained from the remaining 89 patients. Forty-three patients were undergoing one-visit treatment (group 1) and 46 undergoing two-visit treatment (group 2). Most patients in both groups reported no pain or only slight pain within each post-obturation interval, only one in group 1 and one in group 2 had flare-ups and slight swelling. There was no statistically significant difference in the incidence and intensity of post-obturation pain experienced by two groups. The incidence and intensity of post-obturation pain experience following one- or two-visit RCT on teeth with vital pulps and a single canal were not significantly different.

The Effect of Niella sativa Linn. Ground Seed Extract on Cotton Pellet Induced Inflammation in Rats

The study was done to find out the anti-inflammatory effects of the ethanolic extract of ground seeds of Nigella swim in inflammed rats. The effect was compared with reference standard drugs aspirin and hydrocortisone. Chronic it was induced by implantation of a sterile cotton pellet in rut's groin region. Treatment with Nigella saliva extract at a dose of 250 mg/kg body weight and at a dose of 500 mg/kg body weight orally daily for 14 days produced anti-inflammatory effect. The percentage of inhibition of granuloma formation were 19.30% and 41.42% respectively. Administration of aspirin and hydrocortisone for 14 days showed also anti-inflanunatoq effect and the percentage of inhibition of granuloma formation were 27.67% and 38.58% respectively.

Comparison of 2% chlorhexidine and 5.25% sodium hypochlorite irrigating solutions on postoperative pain: A randomized clinical trial

To compare the levels of postoperative pain after cleaning and shaping of root canals using two different root canal irrigants for debridement. Forty patients with irreversible pulpitis, pulp necrosis and non-vital teeth exhibiting acute apical periodontitis requiring root canal treatment were included. At random, canals were cleaned and shaped with the following protocols. 2% chlorhexidine solution in group I and 5.25% sodium hypochlorite solution in group II were used as an irrigants. Access cavities were closed with a sterile cotton pellet and cavit. The patients recorded degree of pain at various time intervals after cleaning and shaping on a visual analogue scale for 1 week. The mean pain score for group I was between 0.65 and 3.35 and for group II was between 0.95 and 4.50. There was significant difference in the pain level between the two groups only at 6 th hour postoperatively (P<0.05) and the pain was more in sodium hypochlorite group. More pain was present in teeth irrigated using 5.25% sodium hypochlorite when compared to that in teeth irrigated using 2% chlorhexidine solution. Significant difference in pain level was present only at 6th hour postoperatively, and at all other periods (24 th hour, 4 th and 7 th days) there was no significant difference in pain level between the two groups.

Stimulation of type I collagen activity in healing of pulp perforation

Background : TGF- β 1 is a connective tissue stimulant, potential regulator for tissue repair, and promoter in wound healing. The healing of pulp perforation is decided by quantity and quality of new collagen deposition. TGF- β 1 upregulates collagen transcription. However, after several weeks production of type I collagen synthesis is stopped and enzymatic degradation of collagen matrix will occur. Purpose : Observe synthesis type I collagen during the process of pulp perforation healing in 7, 14, and 21 days after being treated using TGF- β 1. Methods : This research in vivo from orthodontic patients indicated for premolar extraction, between ages 10–15 years. A class V cavity preparation was created in the buccal aspect 1 mm above gingival margin until pulp exposure. Cavity was irrigated slowly with saline solution and dried with a sterile small cotton pellet. The sterile absorbable collagen membrane used, soaked with 5 μl of TGF- β 1. It was covered by teflon pledge to separate from glass ionomer cement as restoration. Evaluated on day 7 th , 14 th , and 21 st . All samples were extracted and prepared for immunohystochemical examination. Result : Data were analyzed by t-test. There was significant difference in synthesis type I collagen compared between 7–14 days and 7–21 days after treatment by TGF- β 1 also Ca(OH) 2 . There was significant difference compared between TGF- β 1 and Ca(OH) 2 in 14–21 days after treatment (means TGF- β 1 > Ca(OH) 2 ). Conclusion : Elevation of synthesis type 1 collagen by TGF- β 1 in 20 mg/ml.

Pulp tissue inflammation and angiogenesis after pulp capping with transforming growth factor β1

In Restorative dentistry the opportunity to develop biomemitic approaches has been signalled by the possible use of various biological macromolecules in direct pulp capping reparation. The presence of growth factors in dentin matrix and the putative role indicating odontoblast differentiation during embryogenesis has led to the examination on the effect of endogenous TGF- β1. TGF- β 1 is one of the Growth Factors that plays an important role in pulp healing. The application of exogenous TGF- β 1 in direct pulp capping treatment should be experimented in fibroblast tissue in-vivo to see the responses of inflammatory cells and development of new blood vessels. The increase in food supplies always occurs in the process of inflammation therefore the development of angiogenesis is required to fulfil the requirement. This in-vivo study done on orthodontic patients indicated for premolar extraction between 10–15 years of age. A class V cavity preparation was created in the buccal aspect 1 mm above gingival margin to pulp exposure. The cavity was slowly irrigated with saline solution and dried using a sterile small cotton pellet. The sterile absorbable collagen membrane was applied and soaked in 5 m l TGF- β 1. It was covered by a Teflon pledge to separate from Glass Ionomer Cement restoration. Evaluation was performed on day 7; 14; and 21. All samples were histopathologycally examined and data was statistically analysed using one way ANOVA and Dunnet T3.There were no inflammatory symptoms in clinical examination on both Ca(OH) 2 and TGF- β1, but they increased the infiltration of inflammatory cells on histopathological examination. There were no significant differences (p > 0.05) between Ca(OH) 2 and TGF- β1 in inflammation cell and significant differences (p 0.05) in inflammation cell with in TGF- β1 groups and significant differences (p < 0.05) with in Ca(OH) 2 groups on day 7 and 14. It is concluded TGF- β1 functions as direct capping medication has the same inflammatory response as Ca(OH) 2 , however, TGF- β1 developed angiogenesis earlier than Ca(OH) 2 .

Pulp tissue vacuolization and necrosis after direct pulp capping with calcium hydroxide and transforming growth factor-β1

Mechanical pulp exposure by a rotary cutting instrument or a hand-cutting instrument often happens in deep caries. Application of protective dressing can protect the pulp from additional injury by facilitating healing and repair. Pulp capping has been suggested as one treatment of choice after pulp exposure to maintain pulp vitality. TGF-1 is growth factor that has important rule in wound healing. The application of Ca(OH)2 and exogenous TGF-1 as direct pulp capping tr4eatment must be experimented in-vivo to see the vacuolization and necrosis in7,14 and 21 days after application. This research was done in vivo experiment from orthodontic patients indicated for premolar extraction, between ages 10-15 years. A class V cavity preparation was created in the buccal aspect 1 mm above gingival margin until pulp exposure. Cavity was irrigated slowly with saline solution and dried with a sterile small cotton pellet. Group 1 calcium hydroxide was applied as manufacture procedure. Group 2, the sterile absorbable collagen membrane used, as inert carrier of TGF-1 was soaked with 5 l. All groups were covered by a Teflon pledge to separate pulp capping agent from glass ionomer cement restoration. Teeth extracted in 7, 14 and 21 days after treatment. All samples were hystopathologically examined. There were significant difference of TGF-1 (p

Anti-inflammatory activity of four solvent fractions of ethanol extract of Mentha spicata L. investigated on acute and chronic inflammation induced rats

Anti-inflammatory effects of four solvent fractions of ethanol extract of Mentha spicata were evaluated in acute and chronic inflammation induced in Wistar albino rats. Lipid peroxidation (LPO) and some antioxidants produced during chronic inflammation were quantitated. Hexane (320 mg/kg of body weight in 25% DMSO), chloroform (320 mg/kg body weight in 25% DMSO), ethyl acetate (160 mg/kg body weight in 25% DMSO), aqueous (320 mg/kg of body weight in ddH 2O) fractions, two negative control groups (25% DMSO and ddH 2O) and two anti-inflammatory drugs (Diclofenac: 25 mg/kg of body weight; Indomethacin: 10 mg/kg of body weight both in ddH 2O) were administered by oral intubations to the eight groups of rats consisting six animals, each. In acute study, 1% carrageenan was injected subcutaneously in the sub-plantar region of the right hind paw after 1 h of administration of test doses. The increased paw edema was measured at 0.5, 1, 2, 4, 8, 16 and 24 h intervals. In the chronic study, the oral administration was carried out for seven consecutive days. On eighth day, four sterile cotton pellets (50 mg each) were implanted subcutaneously in the dorsal region of the rats. On the sixteenth day, the rats were sacrificed and the cotton pellets with granulomatous tissue were dissected out and weighed (fresh and dry). Both in chronic and acute inflammation, ethyl acetate (EAF) and aqueous fraction (AF) were effective. EAF is comparable with the positive standards in chronic inflammation. The results indicate that EAF's anti-inflammatory activity is largely due to its ability to modulate in vivo antioxidants.

Histological changes in periodontal tissue caused by the application of citric acid in the treatment of periodontal disease

Introduction: Surface conditioning of teeth with periodontal disease in the surgical treatment of periodontal disease has an important role in the reparation of periodontal tissue. The aim of this study was to evaluate histologically the effect of citric acid on the induction of connective tissue attachment, i.e. cementogenesis and the resorption of cementum and dentin after flap reposition on the exposed tooth surfaces. Materials and Methods: The study was conducted on 12 "White Landras" pigs, 6 male and 6 female, with deciduous dentition. The "split mouth" technique was used for more adequate assessment and comparison of data. Exposed surfaces of the upper left canine were treated with laterally positioned flap (LPF) and their counterparts with free gingival graft (FGG). The recipient site was prepared by tissue excision and the tooth surface was prepared using hand instruments. The donor site for LPF was the edentulous region lateral to the treated tooth, where the full width flap was lifted to completely cover the exposed root surface over the enamel-cementum junction. In the experimental group, a fresh solution of citric acid (pH=1) was applied for 3-5 min with a sterile cotton pellet prior to the flap reposition. The tooth was rinsed with saline and the wound was sutured with single sutures. In the control group, the identical surgical treatment was performed but without citric acid. FGG, i.e. half width flap taken from the edentulous region lateral to the treated teeth, was used to cover the exposed tooth surfaces. Prior to FGG positioning in the experimental group, citric acid was applied in the same manner as in animals treated with LPF. The graft covered the exposed root surface. Fixation was done with single sutures and the wound was additionally preserved with surgical dressing. The control group was treated without citric acid. The animals were sacrificed eight weeks after the treatment. The material was prepared in a routine manner for histological sampling under light microscopy. After 10% formalin fixation, the material was decalcified for 7-10 days. Paraffin molds were cut in 5 ?m thick slices which were stained with haematoxylin eosin (HE), Masson-Trichrome and Paf-Hallmi. Periodontal tissue status in experimental animals was analyzed under the light microscope. Results: Citric acid applied on the exposed tooth surface during the flap surgery had a positive effect on cementogenesis. Cementoblasts were observed along root cementum in thick rows. Newly formed cementum was hyperplastic, with regular laminar structure and more evident on animal models treated with full width flap. No damage of odontoblasts or pulpal connective tissue was observed.

Histological Study of Periradicular Tissue Responses to Uninfected and Infected Devitalized Pulps in Dogs

Uninfected necrotic tissue, such as that which follows a myocardial or cerebral infarct, is capable of inducing an inflammatory reaction. Eventually, the infarct is organized by granulation tissue. Why then, does uninfected devitalized pulp tissue, such as in traumatized teeth, not cause periradicular inflammation and does not become organized by granulation tissue? Four beagle dogs were used in this experiment. A total of 48 teeth, which included 24 maxillary and 24 mandibular incisors, were aseptically devitalized, leaving residual pulp tissues in the root canals, and equally divided into two groups. Group A (24 uninfected): A sterile cotton pellet was placed deep into the canal orifice before the pulp chamber and access opening were closed with a layer of zinc-oxide eugenol cement followed by glass ionomer cement. Group B (24 infected): The teeth were left open to the oral cavity for 7 days and then closed with a cotton pellet and zinc-oxide eugenol and glass ionomer cement. The animals were sacrificed one year after the experiment and prepared for histological examination of periradicular tissue responses to uninfected and infected devitalized pulp tissues. The results indicate that uninfected devitalized pulp tissues did not continuously release inflammatory mediators and cause persistent periradicular inflammation over a period of one year. However, infected devitalized pulp tissues induced various degrees of periradicular inflammation. Only the apical few millimeters of uninfected devitalized pulp tissue in the root canals were organized by granulation tissue from vital periodontal ligament tissue.

Effect of MTAD on Postoperative Discomfort: A Randomized Clinical Trial

The purpose of this study was to compare levels of postoperative discomfort after cleaning and shaping of root canals using two protocols for removal of smear layer. Seventy-three consecutive patients requiring root canal treatment were included. At random, canals were cleaned and shaped with one of the following protocols. In group 1, 5.25% sodium hypochlorite was used as the root canal irrigant. The smear layer was removed by placing 17% EDTA in the canal(s) for 1 min followed by a 5-ml rinse with 5.25% NaOCl. In group 2, canals were irrigated with 1.3% NaOCl; the smear layer was removed by placing MTAD in the canal(s) for 5 min. Access cavities were closed with a sterile cotton pellet and Cavit. The patients recorded degree of discomfort at various time intervals after cleaning and shaping on a visual analogue scale for 1 wk. No significant statistical difference was found in the degree of discomfort between the two groups (p = 0.58).

Nematicidal activity of essential oils and organic amendments from Asteraceae against root‐knot nematodes

The essential oil of Chrysanthemum coronarium flowerheads showed strong nematicidal activity in vitro and in growth‐chamber experiments. Essential oil concentrations of 2, 4, 8 and 16 µL mL−1, significantly reduced hatch, J2 survival (determined by final value and area under curves of cumulative percentage hatch or mortality) and reproduction rate of Meloidogyne artiellia in vitro, with the lowest values occurring at 16 µL mL−1. In pot trials with chickpea cv. PV 61, essential oil concentrations of 10–40 µL per 500 cm3 soil, applied on sterile cotton pellets, also significantly reduced the nematode's reproduction rate. The biological processes of mortality and hatching/reproduction were adequately described by the monomolecular and expanded negative exponential models, respectively. Effectiveness of soil amendment with either flowers, leaves, roots or seeds of C. coronarium, and flowers from several species of Asteraceae (Chrysanthemum segetum, Calendula maritima, Calendula officinalis and Calendula suffruticosa) at 5 g per 500 cm3 soil was tested for suppression of M. artiellia and growth of chickpea cv. PV 61 under growth‐chamber conditions. In these tests, flowers of all five Asteraceae species and various parts of C. coronarium significantly reduced reproduction rates of M. artiellia, by 83·0–95·9%, with the minimum rates occurring in infected chickpea plants amended with flowers of C. officinalis and C. suffruticosa. The in vitro and in planta results suggest that the essential oil of C. coronarium and organic amendments from Asteraceae species may serve as nematicides.