Dor, ansiedade e qualidade de vida relacionada à saúde bucal de pacientes atendidos no serviço de urgência odontológica

Resumo O objetivo deste estudo foi avaliar associação entre dor pré-operatória, ansiedade e impacto da condição bucal na qualidade de vida dos pacientes atendidos no serviço de Urgência Odontológica da Universidade Federal dos Vales do Jequitinhonha e Mucuri. Estudo transversal retrospectivo foi conduzido avaliando dados clínicos de 240 prontuários de pacientes com idades entre 18 e 65 anos. A dor foi mensurada pela Heft-Parker Visual Analogue Scale; ansiedade, pela Corah’s Detal Anxiety Scale e qualidade de vida, pelo Oral Health Impact Profile (OHIP-14). Associações foram analisadas pelo Teste qui-quadrado de Pearson (p < 0,05). Foi observada associação estatisticamente significante entre dor e pior qualidade de vida, com impacto nos domínios desconforto psicológico (p < 0,001), incapacidade física (p < 0,001), psicológica (p < 0,001) e social (p < 0,001). Ansiedade influenciou na pior qualidade de vida, com impacto nos domínios desconforto psicológico (p = 0,009), incapacidade fisica (p = 0,016), psicológica (p = 0,011) e desvantagem social (p = 0,028). Esse estudo é relevante para o planejamento de ações voltadas para a saúde bucal dos pacientes atendidos nos serviços de urgência odontológica, priorizando aqueles com maiores impactos psicossociais decorrentes dos problemas bucais.

Biocompatibility of a New Dental Glass Ionomer Cement with Cellulose Microfibers and Cellulose Nanocrystals

Developing new restorative materials should avoid damage to tissue structures. This study evaluated the biocompatibility of a commercial dental glass ionomer cement (GIC) mechanically reinforced with cellulose microfibers (GIC+CM) or cellulose nanocrystals (GIC+CN) by implantation of three test specimens in subcutaneous tissue in the dorsal region of 15 Rattus norvegicus albinus rats. Each rat received one specimen of each cement, resulting in the following groups (n=15): Group GIC (Control), Group GIC+CM and Group GIC+NC. After time intervals of 7, 30 and 60 days, the animals were sacrificed and the following aspects were histologically evaluated: type of inflammatory cells, fibroblasts, blood vessels, macrophages, giant cells, type of inflammatory reaction and capsule thickness (µm). These events were scored as (-) absent, (+) light, (++) moderate and (+++) intense. The results were statistically analyzed by Kruskal-Wallis test and Mann-Whitney post test. At 7 days, Group GIC+NC showed more favorable tissue repair because quantitatively there were more fibroblasts (p=0.022), fewer macrophages (p=0.008) and mononuclear cells (p=0.033). Polymorphonuclear neutrophils and giant cells were absent in all experimental periods. At 60 days, test specimens in Group GIC+NC were surrounded by a fibrous tissue capsule with reduced thickness (26.72±2.87 µm) in comparison with Group GIC+CM (41.21±3.98 µm) (p=0.025). In general, all biomaterials showed satisfactory biocompatibility, but glass ionomer cement modified with cellulose nanocrystals showed a more advanced tissue repair.

Management of Cyst-like Periapical Lesions by Orthograde Decompression and Long-term Calcium Hydroxide/Chlorhexidine Intracanal Dressing: A Case Series

Cyst-like periapical lesions should be treated initially with conservative nonsurgical procedures. In this case series, we describe the clinical and radiographic outcomes of large cyst-like lesions that were treated by orthograde decompression and long-term intracanal use of calcium hydroxide [Ca(OH)2] mixed with 2% chlorhexidine digluconate. Ten cases of cyst-like periapical lesions involving 15 teeth from 10 patients were selected. Maximal radiographic diameters of the lesions ranged from 11 to 28 mm. Nonsurgical procedures were performed, including apical patency, orthograde puncture of cyst-like exudates, chemomechanical preparation, and placement of intracanal Ca(OH)2/CHX dressings, which were periodically replaced during 6-10 months. The root canals were then filled with gutta-percha and sealer. The follow-up periods ranged from 6 to 24 months, and the outcome was classified as healed, healing, or failure. Nine lesions drained copious exudates after canal patency. One lesion only drained bloody serous exudate after periapical overinstrumentation. In 9 patients, intracanal exudation ceased in the first follow-up visit. At the 24-month follow-up, 6 lesions (60.0%) had healed, and 3 lesions (30.0%) were healing, with the corresponding patients being without clinical signs or symptoms. The case of treatment failure was submitted to surgical treatment. Microscopically, the lesion appeared to be an apical cyst with exuberant extraradicular bacterial biofilms attached to the sectioned root apex. This case series supports the use of nonsurgical methods to resolve larger cyst-like periapical lesions.

Strategy for apexification of wide-open apex associated with extensive periapical lesion in a weakened root

This case report describes successful apexification for a challenging case involving a 30-year-old man, who suffered from dental trauma involving tooth No. 7 (which had occurred several years earlier) and recently experienced acute periapical abscess in this region. Radiographic analysis revealed incomplete root formation, a wide-open apex, thin root canal walls, and an extensive periapical lesion. Chemomechanical debridement was performed gently using K-files and irrigation with a 1% sodium hypochlorite solution. The root canal was filled with a calcium hydroxide paste, which was replaced periodically. At 18 months post-treatment, an apical barrier tissue and significant reduction of periapical radiolucency were observed; at that time, the entire root canal was filled with gray mineral trioxide aggregate (MTA). At a follow-up 16 months later, the tooth had normal function and periapical repair was complete.

Endodontic management of a long-standing horizontal mid-root fracture: case report in a young patient

The purpose of this case report was to present the successful endodontic management of a long-standing horizontal mid-root fracture in a permanent maxillary central incisor. A 12-year-old boy with a history of traumatic injury sustained 15 months previously to the maxillary central incisor presented for treatment. Clinical examination revealed physiological mobility, pulp chamber exposed to the oral environment, and the buccal mucosa with a sinus tract in the area of the traumatized tooth. A radiolucent lesion at the fracture line and apical fragment with obliteration of the root canal space were observed radiographically. Conservative root canal treatment of the coronal segment was performed using calcium hydroxide as an intracanal dressing. The calcium hydroxide was replaced every 8 weeks for 10 months. A hard tissue barrier was observed after this period, and the coronal fragment of the root canal was filled. After 4 years, the tooth was asymptomatic and functional and no periapical lesion was observed.

Orthograde retreatment failure with extruded MTA apical plug in a large periradicular lesion followed by surgical intervention: case report

Absence of periapical healing after orthograde retreatment using an apical plug with mineral trioxide aggregate (MTA) can require surgical intervention. A patient with a root-filled maxillary central incisor with chronic apical periodontitis and sinus tract was referred for endodontic retreatment. Excessive apical enlargement was verified, indicating an MTA apical plug placement; however, an unintentional extrusion of MTA occurred during this step. The root canal was filled with gutta-percha and sealer, and periodic recalls were scheduled. The sinus tract was observed after six months and the lesion remained unaltered, although the extruded MTA had resorbed; therefore, an apicoectomy and retrograde root-end filling with MTA were performed. Absence of sinus tract, normal clinical aspect, and complete repair of the lesion were observed at the two-year follow-up.

The efficacy of a cervical barrier in preventing microleakage of Enterococcus faecalis in endodontically treated teeth

The clinical failure of coronal restorations can compromise the healthy periapical status of endodontically treated teeth. The purpose of the present ex vivo study was to assess the effectiveness of the cervical barrier in preventing bacterial microleakage in the eventual loss of the coronal restoration. Following removal of the smear layer and obturation to the cementoenamel junction using gutta-percha, 70 single-rooted mandibular premolars were randomly divided into five different groups: Group 1 received no additional treatment; Groups 2 and 3 had 2 mm and 3 mm of the obturation removed, respectively, followed by placement of a cervical barrier that was the same thickness as the obturation. In Group 4 (positive control), the root canals were filled only with gutta-percha, while in Group 5 (negative control), the root canals were completely impermeabilized following obturation. The filled root canals were incorporated into a split-chamber model system using Enterococcus faecalis as a microbial marker. The apices were suspended in the lower chambers. Leakage was determined daily for 60 days and evaluated for turbidity. According to Fisher's exact test, the cervical barrier in Groups 2 and 3 prevented the microleakage of E. faecalis into the root canals when compared with Groups 1 and 4. This result was similar to that for the completely sealed samples in Group 5 (p = 0.001).

Periapical repair in dog teeth: root canal adhesive filling by using the Resilon System

INTRODUCTION

New filling biomaterials with better physicochemical properties would create a favorable biologic environment for the healing of periapical tissues. The aim of this study was to evaluate periapical repair after biomechanical preparation and root filling with an adhesive system compared with the gold standard material (gutta-percha+sealer) in dog teeth.

METHODS

The pulp of 25 root canals was removed. The apical cementum layer was perforated, and the root canals were prepared up to size #60 K-file followed by step-back shaping with the #90 K-file and filled by the lateral condensation technique. In the experimental group (n=15), the Resilon System (Pentron Clinical Technologies, Wallingford, CT) was used. As a control material (n=10), gutta-percha cones and pulp canal sealer were used. After 60 days, the animals were killed, and 10 histologic parameters were evaluated. Differences among the groups were analyzed by using the Mann-Whitney and Fisher exact tests.

RESULTS

In radiographic and histologic evaluations, most fillings were slightly short of the apex. Progressive regenerative stages were observed; however, there was a reduced prevalence of biologic foraminal closure. No significant differences were observed between the 2 biomaterials with regard to any of the parameters evaluated (P>.05).

CONCLUSIONS

The Resilon System shows periapical biocompatibility equivalent to the gold standard material.

Radiographic quality of root canal fillings performed in a postgraduate program in endodontics

The aim of this study was to evaluate the standard quality of 1,347 root fillings performed by postgraduate students in Endodontics according to 3 radiographic quality parameters. The analyzed quality parameters included apical extension (AE), taper (TA) and homogeneity (HO), which received scores S2 (ideal standard), S1 (slight deviation) or S0 (accentuated deviation). A perfect filling (PF) received S2 for all parameters. In the absence of one or two S2 score, the fillings were deemed as satisfactory (SF) or deficient (DF), respectively. The results showed 51.7%, 41.5% and 6.8% of PF, SF, and DF, respectively. AE, TA, and HO presented equivalent quality parameters in root-filled canals of mandibular incisors and mandibular premolars (p>0.05). Conversely, in maxillary incisors, canines and distal root of mandibular molars, significant differences (p<0.05) were found between 2 parameters. Besides, there were significant differences (p<0.05) among the measured parameters in root-filled canals of maxillary premolars, all root canals of the maxillary molars and mesial root of the mandibular molars. AE showed the lowest frequency of S2 score for all groups. In conclusion the prevalence of perfect, satisfactory and deficient fillings varied significantly according to the root canal group. The quality parameters categorized fillings in 3 complexity degrees. AE was the most critical parameter of quality in root canal fillings.

Elimination of intracanal infection in dogs' teeth with induced periapical lesions after rotary instrumentation: influence of different calcium hydroxide pastes

The aim of this study was to evaluate the antiseptic efficacy of rotary instrumentation associated with calcium hydroxide-based pastes prepared with different vehicles and antiseptics. Chronic periapical lesions were experimentally induced in 72 premolar root canals of four dogs. Under controlled asepsis, after initial microbiological sampling (A1), the root canals were instrumented using the ProFile system in conjunction with 5.25% sodium hypochlorite and the intracanal medication was placed. Four experimental groups were formed according to the pastes used: group 1- Calen (n=18), group 2- Calen+CPMC (n=20), group 3- Ca(OH)₂ p.a.+ anaesthetic solution (n=16) and group 4- Ca(OH)₂ p.a.+ 2% chlorhexidine digluconate (n=18). After 21 days, the pastes were removed; the canals were emptied and 96 hours later a second microbiological sample was obtained (A2). The incidence of positive microbiological cultures and the number of cfus in stages A1 and A2 were compared statistically by the Wilcoxon test while the influence of the different treatments in intracanal infection was evaluated by Kruskal-Wallis test at 5% significance level (p<0.05). Large numbers of strict and facultative anaerobes, and viridans group streptococci were found in 100% of root canals of A1 samples. Among A2 samples, all treatments showed significant reduction of cfus and positive cultures (p<0.05), but only groups 3 and 4 showed 100% of root canals free of microorganisms. Rotary instrumentation plus NaOCl 5.25% associated with intracanal medication produced a drastic reduction or elimination of intracanal microbiota, whose performance was not influenced by the nature of the vehicle or the antiseptic added to the Ca(OH)₂ p.a.

Histomicrobiologic aspects of the root canal system and periapical lesions in dogs' teeth after rotary instrumentation and intracanal dressing with Ca(OH)2 pastes

OBJECTIVE:

The purpose of this study was to evaluate the distribution of microorganisms in the root canal system (RCS) and periapical lesions of dogs' teeth after rotary instrumentation and placement of different calcium hydroxide [Ca(OHy-based intracanal dressings.

MATERIALS AND METHODS:

Chronic periapical lesions were experimentally induced in 80 premolar roots of four dogs. Instrumentation was undertaken using the ProFile rotary system and irrigation with 5.25% sodium hypochlorite. The following Ca(OH)₂-based pastes were applied for 21 days: group 1 - Calen (n=18); group 2 - Calen+CPMC (n=20); group 3 - Ca(OH₂ p.a. + anaesthetic solution (n=16) and group 4 - Ca(OH₂ p.a.+ 2% chlorhexidine digluconate (n=18). Eight root canals without endodontic treatment constituted the control group. Histological sections were obtained and stained with Brown & Brenn staining technique to evaluate the presence of microorganisms in the main root canal, ramifications of the apical delta and secondary canals, apical cementoplasts, dentinal tubules, areas of cemental resorption and periapical lesions. The results were analyzed statistically by the Mann-Whitney U test (p<0.05).

RESULTS:

The control group showed the highest prevalence of microorganisms in all sites evaluated. Gram-positive cocci, bacilli and filaments were the most frequent morphotypes. Similar microbial distribution patterns in the RCS and areas of cementum resorption were observed in all groups (p>0.05). The percentage of RCS sites containing microorganisms in groups 1, 2, 3, 4 and control were: 67.6%, 62.5%, 78.2%, 62.0% and 87.6%, respectively.

CONCLUSION:

In conclusion, the histomicrobiological analysis showed that the rotary instrumentation and the different calcium hydroxide pastes employed did not effectively eliminate the infection from the RCS and periapical lesions. However, several bacteria seen in the histological sections were probably dead or were inactivated by the biomechanical preparation and calcium hydroxide-based intracanal dressing.

Endodontic re-treatment associated with the elimination of amalgam root-end filling through sinus tracts: a report of two cases

Two patients presented with complaints of recurrent drainage of purulent exudate from sinus tracts, inflammation and pain after endodontic re-treatment of the maxillary left (Case 1) and right (Case 2) lateral incisors. The periapical lesions persisted after apical curettage, apicectomy and root-end filling with silver amalgam. Radiographic examination exposed the poor quality of the endodontic treatments and the silver amalgam root-end fillings, which were associated with periapical radiolucent areas in both teeth. The sinus tract persisted after root canal cleaning and shaping, followed by a calcium hydroxide root canal dressing. The root-end fillings were periapically dislodged with endodontic K-files, and showed progressive displacement by sinus tracts up to elimination in the oral cavity. Follow ups of 42 and 65 months post procedure revealed clinical disappearance of the symptoms, sinus tracts and exudates, and radiographs revealed that the repair process of the periapical radiolucent areas was quite advanced.

Influence of luting agents on time required for cast post removal by ultrasound: an in vitro study

Objective:

This in vitro study evaluated the influence of luting agents on ultrasonic vibration time for intraradicular cast post removal.

Material and Methods:

After endodontic treatment, 30 roots of extracted human canines were embedded in resin cylinders. The post-holes were prepared at 10 mm depth and their impressions were taken using autopolymerizing acrylic resin. After casting procedures using a nickel-chromium alloy, the posts were randomly distributed into 3 groups (n=10) according to the luting material: G1- zinc phosphate (SS White) (control group), G2 - glass ionomer cement (Vidrion C; SS White), and G3- resin cement (C&B; Bisco). In G3, the adhesive procedure was performed before post cementation. After 24 h, the cement line was removed at the post/tooth interface using a fine diamond bur, and the ST-09 tip of an Enac ultrasound unit was applied at maximum power on all surfaces surrounding the posts. The application time was recorded with a chronometer until the post was completely dislodged and data were analyzed by ANOVA and Tukey's test (p<0.05).

Results:

The roots were removed from the acrylic resin and inspected to detect cracks and/or fractures. The means for G1, G2, and G3 were 168.5, 59.5, and 285 s, respectively, with statistically significant differences among them. Two G3 posts resisted removal, one of which developed a vertical fracture line.

Conclusions:

Therefore, the cement type had a direct influence on the time required for ultrasonic post removal. Compared to the zinc phosphate and glass ionomer cements, the resin cement required a longer ultrasonic vibration time.

Effect of rotary instrumentation and of the association of calcium hydroxide and chlorhexidine on the antisepsis of the root canal system in dogs

This study aimed at evaluating the antisepsis of the root canal system (RCS) and periapical region (PR) provided by rotary instrumentation associated with chlorhexidine + calcium hydroxide as intracanal medicament. Chronic periapical lesions were induced in 26 pre-molar roots in two dogs. After microbiological sampling, automatic instrumentation using the Profile system and irrigation with 5.25% sodium hypochlorite solution, with a final rinse of 14.3% EDTA followed by profuse irrigation with physiological saline were carried out in 18 root canals. After drying the canals, a paste based on calcium hydroxide associated with a 2% chlorhexidine digluconate solution was placed inside them. After 21 days, the medication was removed, leaving the root canals empty and coronally sealed. After 96 hours, a final microbiological sample was obtained, followed by histomicrobiological processing by the Brown & Brenn method. Eight untreated root canals represented the control group (C-G). Based on the Mann-Whitney test at a confidence level of 5% (p < 0.05), the procedures of antisepsis used offered significant efficacy (p < 0.05) resulting in 100.0% of the canals free of microorganisms. In the C-G, an elevated incidence of various microbial morphotypes was confirmed in all sites of the RCS, with the presence of microbial colonies in the periapical region. In contrast, the experimental group showed a similar pattern of infection in the RCS, although less intense and a reduced level of periapical infection (p < 0.05). It was concluded that adequate instrumentation followed by the application of calcium hydroxide + chlorhexidine offered significant elimination of microorganisms.

Residual antibacterial activity of chlorhexidine digluconate and camphorated p-monochlorophenol in calcium hydroxide-based root canal dressings

The purpose of this study was to evaluate the residual antibacterial activity of several calcium hydroxide [Ca(OH)2]-based pastes, placed in root canals of dogs' teeth with induced chronic periapical lesions. Root canals were instrumented with the ProFile rotary system and filled with 4 pastes: G1 (n=16): Ca(OH)2 paste + anesthetic solution; G2 (n=20): Calen® paste + camphorated p-monochlorophenol (CMCP); G3 (n=18): Calen®; and G4 (n=18): Ca(OH)2 paste + 2% chlorhexidine digluconate. After 21 days, the pastes were removed with size 60 K-files and placed on Petri plates with agar inoculated with Micrococcus luteus ATCC 9341. Pastes that were not placed into root canals served as control. After pre-diffusion, incubation and optimization, the inhibition zones of bacterial growth were measured and analyzed by Mann-Whitney U test at 5% significance level. All pastes showed residual antibacterial activity. The control samples had larger halos (p<0.05). The mean residual antibacterial activity halos in G1, G2, G3 and G4 were 7.6; 10.4; 17.7 and 21.4 mm, respectively. The zones of bacterial growth of G4 were significantly larger than those of G1 and G2 (p<0.05). In conclusion, regardless of the vehicle and antiseptic, all Ca(OH)2-based pastes showed different degrees of measurable residual antibacterial activity. Furthermore, unlike CMCP, chlorhexidine increased significantly the antibacterial activity of Ca(OH)2.

Influence of sodium hypochlorite-based irrigants on the susceptibility of intracanal microbiota to biomechanical preparation

This study evaluated the microbiological conditions of root canals, using smears and culture from anterior teeth and premolars with necrotic pulps associated with chronic periapical pathologies, before and after biomechanical preparation (BMP). During double-flared instrumentation, 1, 2.5 and 5% sodium hypochlorite (NaOCl)-based irrigants were used in 3 groups: GI (n=39), GII (n=36) and GIII (n=36), respectively. Before BMP, all cultures were positive and the smears showed microbiologically diverse morphotypes, including fusiforms, pleomorphic, rods, cocci and filaments. Quantitetively, 20, 20 and 23 morphotypes were identified in GI, GII and GIII, respectively). After BMP, the percentages of negative cultures in GI, GII and GIII were 74.2%, 86.3% and 93.4% (p>0.05) and the number of morphotypes decreased to 14, 15 and 5, respectively. All teeth with 2 root canals and/or associated fistulas were microbiologically negative after BMP, regardless of irrigant concentration. Gram-negative morphotypes were more susceptible to the action of irrigants. After irrigation with 5% NaOCl, only structural arrangements consisting of Gram-positive cocci and bacilli persisted. Thus, BMP plus 5% NaOCl offered the best antiseptic potential because in the few positive cultures a significant reduction in the number of microbiological morphotypes was also shown (p<0.05).

Evaluation of cytotoxicity of two endodontic cements in a macrophage culture

Compared to gutta-percha, the endodontic cements are used in small quantity to seal root canals, but are indispensable to achieve hermetically sealed margins, where its biocompatibility depends on the sum of responses of each cell present in the periapical region. The object of this study was to evaluate the cytotoxicity of two endodontic cements, one based on epoxy resin (Sealer 26) and the other containing zinc oxide eugenol (Endofill) by using cultured peritoneal macrophages from Swiss mice to measure the induced production of nitric oxide. After solidification and pulverization, aliquots of 100mul of suspension containing 18mg/mL of the respective cements were added to 96-well tissue culture plates containing the tissue culture of macrophages at a concentration of 5.0X10(6) cells/ml. In the positive control group the cell culture was treated with 10mg/mL of lipopolyssaccharide from Escherichia coli 026:B6 and the cell culture alone represented the negative control. After 48 hours of incubation, at 37ºC, in 5% CO2, the cultures were placed in an ELISA automatic reader to evaluate the release of nitric oxide. The production of nitric oxide for cement Sealer 26 was between 36.1 and 313.0 mumols, with a mean of 143.82±111.03mumols, while for the Endofill these values were significantly less (p=0.01), varying from 50.8 to 125.7mumols, with a mean of 80.33±28.42 mumols. In the positive and negative control groups the mean release of nitric oxide was of 162.75mumols and 4.42mumols, respectively. There was no significant difference between the positive control group and cement Sealer 26 (p>0.05). Therefore, the cement Sealer 26 caused significantly greater toxicity to the macrophages, possibly due to the components from the epoxy resin and formaldehyde release during polymerization.

Effect of biomechanical preparation and calcium hydroxide pastes on the antisepsis of root canal systems in dogs

In the endodontic treatment of root canals with necrotic pulps associated with periapical radiolucent areas, one of the main objectives of treatment consists in eliminating the microorganisms spread throughout the ramifications of the root canal system. The scope of this study was to evaluate the antiseptic efficacy of biomechanical preparation and two calcium hydroxide-based pastes, in dogs' teeth with experimentally induced chronic periapical lesions. After initial microbiological sampling, instrumentation of the root canals was undertaken using the conventional technique, using K type files used in conjunction with a solution of 5.25% sodium hypochlorite. After ninety-six hours, further microbiological sampling was undertaken and Calen/CPMC or Calasept pastes were applied for 15 and 30 days. Ninety six hours after the removal of the medication, the third microbiological sampling was undertaken and finally histomicrobiological analysis followed using Brown & Brenn staining. The results were analyzed using the Kruskall-Wallis test, with a level of significance established at 5% (p<0.05). It was shown that the biomechanical preparation significantly reduced the number of colony forming units of microorganisms in root canals. In contrast, there was no significant difference between the antiseptic action of long-term dressings over two periods of action, although 30 days produced a greater reduction in the quantity of microorganisms and of positive microbiological cultures. In histological sections of the four experimental groups, similar microbiological patterns were shown (p>0.05), characterized by an elevated incidence of cocci, bacilli and filaments, predominantly gram-positive, in root canals, secondary canals and accessories, apical cementoplasts and dentinal tubules, but with a low incidence of microorganisms in areas of cementum resorption and the periapical lesion. The biomechanical preparation and intracanal dressing based on calcium hydroxide were important in the antisepsis of the root canal; however, both procedures did not produce significant changes in the microbiological aspects of the root canal system.

Root canal treatment of three-rooted maxillary first and second premolars--a case report

AIM

To report the diagnosis and successful clinical management of a patient with anatomical variation in maxillary first and second premolars.

SUMMARY

Maxillary premolars have a highly variable root canal morphology, but it is rare, especially in the second premolar, to find three canals. This article describes the diagnosis and clinical management of first and second premolars with three canals and three separate roots, drawing particular attention to radiographic interpretation and access refinements.

KEY LEARNING POINTS

Clinicians should be aware of anatomical variations in maxillary premolars and be able to apply this knowledge in radiographic and clinical interpretation. Access cavity refinements may be required for stress-free entry to complex anatomy. Complex premolar anatomy may be predictably managed following its identification and negotiation.

[Clinical and radiographic assessment of single-appointment endodontic treatment in teeth with chronic periapical lesions]

The aim of this study was to evaluate the incidence of postoperative pain and the type of periapical repair, after one-appointment endodontic treatment in asymptomatic patients who presented with pulpal necrosis and radiographically visible chronic periapical lesions. For that, after biomechanical preparation through the step down followed by the step back technique, aided by copious irrigation with 5.0% sodium hypochlorite solution, the filling of the root canals was carried out through the conventional technique, with gutta-percha cones and zinc oxide-eugenol cement. In the immediate postoperative period, 16.6% of all patients presented with spontaneous pain, although the incidence of severe pain--flare-ups--was 3.3%. After twelve months, all patients were asymptomatic and free of fistula, nevertheless only 46.4% exhibited complete resolution of the radiolucent periapical areas. Therefore, in a medium term, the one-appointment endodontic treatment showed 100% of clinical success, but showed a reduced rate of radiographic success.

Cell surface and exopolymer characterization of laboratory stabilized activated sludge from a beverage bottling plant

Fermentor-stabilized activated sludge from an industrial beverage bottling plant was grown on three different food sources: normal plant wastewater, plant wastewater containing high sucrose concentrations, and a synthetic glucose-based feed stock. Surface charge, hydrophobicity, and exopolysaccharide composition were measured on the stabilized bacterial flocs. Cell surface charge was measured by electrophoretic mobility, dye exchange titration, and a standard colloid titration, while cell hydrophobicity was determined using the bacterial adhesion to hydrocarbons (BATH) test. Exopolysaccharide profiles were determined by measuring concentrations of glucose, galactose, mannose, glucuronic, and galacturonic acids in digested exopolymer extractions using HPLC. Changes in the physical surface properties of the bacteria and the chemical composition of the extracted exopolymers were correlated with differences in the three food sources. Cell surface hydrophobicity was similar for cultures grown on different plant wastewaters, while the culture grown on synthetic food produced less floc hydrophobicity. Electrophoretic mobility measurements, charge titrations, and dye exchange titrations showed different total surface charge as well as varying charge availability. Additionally, total surface charge and total exopolysaccharide concentrations appeared less dependent on food source than the food-to-mass ratio. High concentrations of biodegradable food produced dispersed growth and high concentrations of exopolysaccharides that contributed to poor settling.

Comparison of chromium speciation by CZE and ion exchange followed by AAS

The hydrogen chromate anion (HCrO4-), which is the predominant species in acidic solutions and solutions with low chromium concentration, was determined by capillary zone electrophoresis (CZE) using UV detection on-column at 200 nm. A fused-silica capillary (55 cm x 50 microm i.d.) was employed with a high negative voltage of 20 kV. Total chromium was determined after reduction by H2O2 and its complexation by EDTA. The use of H2O2 as reducing agent is advantageous, as it does not increase the conductivity of the solution. Detection limits achieved (for 200 s injection time) were 30 and 8 microg/L for Cr(VI) and Cr(III), respectively. The CZE results obtained for Cr(III) and Cr(VI) were compared with those obtained by ion exchange with subsequent AAS.

[Spontaneous bacterial peritonitis in hepatic cirrhosis: prevalence, predictive factors and prognosis]

BACKGROUND

Spontaneous Bacterial Peritonitis (SBP) is a common and potentially fatal complication of cirrhosis. Multiple variants of this infection have been described during the past decade. Few studies have investigated SBP in Brazil.

MATERIAL AND METHOD

In order to investigate prospectively prevalence, predictive factors and prognosis of the episode of SBP, we studied 143 in and outpatients with cirrhosis admitted to HUCFF and HUPE between January, 1995 and January, 1996. All patients were submitted to a questionnaire, physical examination, blood analysis and abdominal paracentesis with ascitic fluid analysis. They were followed for a mean follow-up period of 4 months and survival was determined.

RESULTS

The prevalence of SBP was 20%. Culture-positive SBP, Culture-negative Neutrocytic Ascites and Bacterascites were identified in 24%, 66% and 10%, respectively. After uni- and multivariate analysis, only anterior gastrointestinal hemorrhage, serum albumin and ascitic fluid C4 reached statistical significance (p = 0.05) as predictive factors for the development of the SBP. The in-hospital and follow-up mortality rates were 33.3% and 53.8% for the SBP patients and 8.5% and 31.9% for the non-SBP patients, respectively (p = 0.01 and p = 0.04). The cumulative probability of survival in the SBP group was significantly lower than the probability of the non-SBP group (p = 0.05).

CONCLUSIONS

We conclude that SBP is a frequent complication, depends of the severity of liver failure and is a marker for poor prognosis in patients with liver cirrhosis.

Lipid metabolism alterations in normotensive subjects with positive family history of hypertension

Metabolic abnormalities are usually reported in hypertensive patients. These metabolic alterations seem to begin in childhood. The young offspring of hypertensive parents have not been studied thoroughly for metabolic alterations. The aim of this study was to examine the level of total cholesterol, LDL cholesterol, VLDL cholesterol, HDL cholesterol, uric acid, glycemia, aldosterone, and plasma renin activity in a population of 42 young, slender normotensive subjects with positive family history of hypertension (FH+) or negative family history of hypertension (FH-). Measurements were made in 20 young normotensive subjects (age 21.1+/-2.2 years, 11 males, 15 white, 5 oriental, body mass index of 22.1+/-2.3 kg/m2) with FH+ and 22 young normotensive subjects (age 19.9+/-1.4 years, 17 males, 17 white, 5 oriental, body mass index of 22.1+/-2.3 kg/m2) with FH-. The total cholesterol (4.47+/-0.8 versus 3.95+/-0.6 mmol/L), LDL cholesterol (2.74+/-0.63 versus 2.36+/-0.61 mmol/L), VLDL cholesterol (0.5+/-0.25 versus 0.35+/-0.09 mmol/L), and triglycerides (2.52+/-1.26 versus 1.76+/-0.5 mmol/L) were significantly elevated (P<.05) in the FH+ group compared with the FH- group. The total cholesterol/HDL cholesterol ratio was significantly higher in the group with a positive family history of hypertension (3.75+/-0.02 versus 3.11+/-0.02, P<.05). Glycemia was slightly elevated in the FH+ group (2.16+/-0.29 mmol/L) but was not significantly different from that of the FH- group (2+/-0.2 mmol/L). Uric acid, plasma renin activity, and aldosterone were similar in both groups. We conclude that young, slender normotensive subjects with a positive history of hypertension show alterations in lipid metabolism, suggesting a positive correlation between lipid metabolism and hypertension heredity.

Carboplatin plus paclitaxel in the first-line treatment of advanced ovarian cancer: preliminary results of a phase I study

This phase I trial was designed to determine the maximum tolerated dose of paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) given as a 3-hour infusion in combination with carboplatin (400 mg/m2) as first-line chemotherapy for stage IIIC/IV ovarian adenocarcinoma. After premedication, paclitaxel was infused over 3 hours, followed by carboplatin infused over 30 minutes on day 1 of a 28-day cycle (group 1, with 28 patients accrued and 150 evaluable cycles) or on day 1 of a 21-day cycle (group 2, with 16 patients accrued and 55 evaluable cycles). Dose-limiting toxicities assessed after the first course included grade 4 neutropenia lasting longer than 7 days, febrile grade 4 neutropenia requiring intravenous antibiotics, grade 4 thrombocytopenia, mucositis greater than grade 2 for more than 7 days, grade > or = 3 nonhematologic toxicity (excluding alopecia, vomiting, and muscular pain), no hematologic recovery on day 42 (for group 1) or on day 35 (for group 2), neurotoxicity above grade 2, and persistence of nonhematologic toxicity (excluding alopecia, nausea/vomiting, and musculoskeletal pain) grade > or = 2 at scheduled re-treatment. If any of the events occurred during the first cycle in three or more of six patients, maximum tolerated dose was considered to have been reached. The hematologic toxicity associated with the two treatment schedules was mainly neutropenia, but it was of short duration. Very few dose reductions or dose delays were necessary. Until now, the six planned courses have been administered without colony-stimulating factors. No toxic death has occurred. Grade 2 or 3 peripheral neuropathy has occurred in 12% of patients, mainly with high doses of paclitaxel. At this time, the maximum tolerated dose has not been reached at paclitaxel 275 mg/m2 every 4 weeks or 225 mg/m2 every 3 weeks, and enrollment continues.

[Recombinant interferon alfa in the treatment of chronic hepatitis C]

BACKGROUND

Chronic hepatitis C usually progresses to cirrhosis and hepatocarcinoma. Treatment with antiviral drugs is indicated attempting to modify the evolution of the disease.

OBJECTIVE

To evaluate the treatment of chronic hepatitis C or post-hepatitis C cirrhosis with interferon-a-R (IFN) and to identify the factors associated with good therapeutic result.

METHODS

Thirty eight patients with chronic hepatitis C or post-hepatitis C cirrhosis were treated with 2.5 or 3.0 MU of IFN three times a week for 6 to 12 months. We considered as a complete and sustained response when ALT and AST were normal for a 6 months period after finishing treatment. We considered complete response with relapse those in whom elevation of the enzymes was detected after drug suspension.

RESULTS

There was normalization of ALT and AST in 17 out of 38 patients (44%). In this group, 9 out of 17 presented a complete and sustained response and in 8 out of 17 there was elevation of the enzymes after drug interruption. There was a trend of better response to interferon in patients below 40 years of age and in those with chronic active hepatitis. The most frequent side effects were fever (80%), myalgia (60%), asthenia (50%), headache (40%), and arthralgia (36%).

CONCLUSION

Treatment with interferon showed a satisfactory and sustained response in 23% of the subjects, with better results in young patients and without cirrhosis.

[The preliminary stage of labor in cattle in relation to the clinical signs of labor and the course of progesterone secretion for the prediction of the calving time]

To evaluate changes in the externally recognizable indications of parturition, the body temperature and progesteroneprofile were examined in 9 Holstein-Friesian heifers and 14 Holstein-Friesian cows in the preparatory phase of parturition. A special external obstetric examination was performed on these animals in the last 263 hours of pregnancy. Furthermore, the vaginal and rectal temperature was measured, and blood samples were taken. Of the blood samples the plasma progesterone concentration was determined. The time of birth could be predicted to be in the next 22 hours on the basis of the relaxation of the broad pelvic ligaments in 52.5% of the cases. A prediction was possible in 43.5% of the cases on the basis of the drop in temperature, and in 91.3% of the animals using the reduction in progesterone levels. Considering the clinical signs of parturition "relaxation of the pelvic ligaments" and a "decrease in temperature", predicting the time of parturition was possible in 65.2% of the animals. In 8.7% of the cases, in which no reduction in the progesterone level below 1.5 ng/ml blood plasma could be seen, the time of delivery could be determined by considering the relaxation of the broad ligaments and the reduction in temperature. A prediction of the time of parturition to be in the next 22 hours was possible for all animals the indicators of parturition.

[Taxol (paclitaxel), first molecule of a new class of cytotoxic agents: taxanes]

Taxol is the first of the taxanes, a new class of cytotoxic agents whose cellular target is the microtubules network. Taxol induces the polymerisation of the alpha and beta sub-units of the tubulin. This mechanism of action which is different from the vinca-alkaloids explains the main cytotoxic activity of paclitaxel through the formation of abnormal and stable bundles of microtubules. Severe hypersensitivity reactions which were seen in early phase I studies are prevented by an oral corticosteroids and H1 and H2 blockers premedication. Profound neutropenia is frequent but of short duration explaining that infectious manifestations are rare and neutropenia not cumulative. Thrombopenia and anemia are rare. Neurotoxicity is dose related but severe peripheral neuropathy is rare. Conduction abnormalities are mainly asymptomatic bradycardias. In second line ovarian cancer and breast metastatic cancer a noticeable level of activity has been observed, and in lung and head and neck cancer Taxol has proved to be effective.

[DNA polymorphism in a Brazilian population: relationship to allele frequencies in France]

The allele frequency distribution of two highly polymorphic DNA sequences was determined in a population from the metropolitan area of Fortaleza (Northeast Brazil). DNAs from 234 individuals were digested with Pvull and successively hybridized to each probe: alpha-Globin 3'HVR and Mucin HVR. The resulting allele frequencies were compared to those observed in a French population. There is no statistically significant difference between these populations in the 3'HVR system. On the contrary, the distribution is statistically different in the Mucin HVR/Pvull system.

[Prevalence of antibodies to hepatitis C (anti HCV) in blood donors in Rio de Janeiro, Brazil. Its relation to ALT and anti HBC]

We have studied 933 volunteer blood donors from May to July, 1990. After a interview and screening tests for syphilis, Chagas disease, malaria and HIV, they underwent an enzyme immunoassay for HBsAg, anti HBc and anti HCV antibodies. Alanine aminotransferase (ALT) serum levels were determined by auto analyser. Most blood donors were male with mean age of 33 years (19-65). Anti HCV prevalence was 3.1% (29 from 933 blood donors). Among anti HCV+, blood donors, 44.8% (13/29) had ALT 40 UI/L, 31% (9/29) were anti HBc+ and 17.2% (5/29) had both surrogate markers simultaneously. From 109 donors with ALT 40 UI/L, 13 (11.9%) were anti HCV+, while among 153 anti HBc+ donors, the anti HCV was 5.8%.

CONCLUSIONS

1) we found a higher anti HCV prevalence among our blood donors than previous published reports from other countries; 2) our data show that surrogate assays do not adequately identify anti HCV blood donors, 41.4% of them would not have been excluded by anti HBc and ALT tests alone; 3) there were a correlation between anti HCV positivity with a sample to cutoff optical density ratio equal or greater than 4 and elevated ALT serum levels.

[DNA polymorphism: comparison of allelic frequencies obtained with two HVR probes in a population from Northeastern Brazil and in two other ethnic groups]

DNAS from 325 individuals representing 2 different populations (234 Brazilians and 91 Asiatics) were analysed for Restriction Fragment Length Polymorphisms (RFLPs). These DNAs were digested with Pvu II enzyme and successively hybridized to two HVR probes: alpha globin-3'HVR and Mucin-HVR. An allele frequency distribution was determined for each couple probe/enzyme and each ethnic groupe studied. The results were compared with frequencies observed in french population and we showed that there is no statistic significant difference between allele frequencies obtained with the couple probe/enzyme 3'HVR/Pvu II in Brazilian and French populations. We also showed that both populations studied (Brazilian and Asiatic) do not follow a Hardy-Weinberg balance.