A 20-year historical prospective cohort study of root canal treatments. A Multilevel analysis.

AIM: To evaluate the number of healthy and functional root filled teeth of patients included in a recall programme for at least 20 years. METHODOLOGY: Teeth were root filled by a single specialist following manual canal instrumentation, lateral/vertical compaction of gutta-percha and restored with glass-ionomer cements and bonding system/composite resin. In a large percentage of teeth, a metal-ceramic crown was placed during follow-up. Patients included in the recall programme (n = 130) were blindly assessed both clinically and radiographically (every 2 years) to evaluate clinical symptoms and periapical status (PAI). The following variables were analysed: age, tooth location, tooth type, initial diagnosis, PAI, root filling length and coronal restoration type. Chi-square test and multilevel analysis were performed to detect variables associated with treatment functionality and disease/lesions (P < 0.05). A cumulative teeth survival curve was constructed by means of Kaplan-Meier using extractions as the end-point. RESULTS: At the 20-year recall, 72 patients (31 M, 41 F; mean age 57.7 ± 8.29 years; 196 teeth) completed the follow-up. Thirty-six patients were excluded for medical complications or died before the end of the study. Drop-outs consisted of 22 patients (17%) who did not complete the follow-up. Single metal-ceramic crowns were positioned after 4-6 months in 40% of teeth. Composite restorations were replaced with single metal-ceramic crowns during the follow-up in 53% of teeth after 8-19 years. Of 196 teeth, 155 were classified as Survived (79%), 128 of which (65%) were Healthy (PAI ≤ 2). Thirty-nine teeth (20%) were extracted for nonendodontic reasons. Twenty-nine teeth (15%) were classified as: re-exacerbation (11 teeth; 5.6%) or persistent asymptomatic lesions (18 teeth; 9%). Only two re-exacerbated teeth were extracted. Multilevel analysis confirmed the clinical relevance of tooth type (P = 0.001) on Survived and healthy teeth (P = 0.007). Tooth location (P = 0.0045) and initial diagnosis (P = 0.019) significantly affected only Healthy teeth. CONCLUSIONS: Root filled teeth were more frequently extracted for non-endodontic reasons rather than for endodontic disease. The majority of teeth with adequate root fillings, adequate restorations and included in a recall programme remained functional and healthy for more than 20 years.

Survival and periapical health after root canal treatment with carrier-based root fillings: five-year retrospective assessment.

AIM: This retrospective study explored survival and periapical healing outcomes in teeth root filled with Thermafil obturators. METHODOLOGY: Root canals of 213 teeth (94 subjects, mean age 48 ± 13 years), instrumented with a step-down technique, irrigated with 5% NaOCl and 10% EDTA and filled with Thermafil and AH Plus sealer, were involved in a recall programme. Teeth were retrospectively re-examined after 5 ± 1 years in a controlled environment. Clinical and radiographic data that were collected included the following: preoperative Periapical Index (PAI) score and signs/symptoms, treatment type, root filling length and presence/absence of voids, restoration type, follow-up PAI score and signs/symptoms. Teeth were considered 'healthy' (PAI ≤ 2, no signs/symptoms) or 'diseased' (PAI ≥ 3, signs/symptoms present, retreated, extracted for endodontic reasons). Two PAI-calibrated examiners assessed outcomes blinded to preoperative status. Bivariate and multilevel analyses were performed at level of patient and tooth (α = 5%). RESULTS: Of 213 teeth treated, 187 (88%) survived and 26 were extracted, six (3%) for persistent endodontic infection (considered 'diseased'), and 20 (9%) for root fracture, periodontal disease or coronal fracture (excluded from analysis). Whilst survival was significantly associated with tooth type (P = 0.015), type of treatment (P = 0.012) and pulpal/periapical diagnosis (P = 0.035), none of these variables were substantiated as survival predictors by the multilevel analysis. A total of 164 of 193 teeth (85%) were assessed as 'healthy', with significantly higher (chi-square; P < 0.04) 'healthy' rates for teeth with PAI score ≤2 and root fillings of adequate length. Multilevel analysis identified PAI score ≤2 (P = 0.002) as the only predictor of periapical health. CONCLUSIONS: In this 5 ± 1 year retrospective assessment, survival and healing rates after root canal treatment with Thermafil root fillings were comparable to those previously reported for conventional root filling techniques.

Structural analysis of HyFlex EDM instruments.

AIM: To compare the phase transformation behaviour, the microstructure, the nano-hardness and the surface chemistry of electro-discharge machined HyFlex EDM instruments with conventionally manufactured HyFlex CM. METHODOLOGY: New and laboratory used HyFlex EDM were examined by X-ray diffraction (XRD) and differential scanning calorimetry (DSC). Nano-hardness and modulus of elasticity were also investigated using a maximum load of 20 mN with a minimum of 40 significant indentations for each sample. Raman spectroscopy and field emission-scanning electron microscope (FE-SEM) were used to assess the surface chemistry of HyFlex EDM. HyFlex CM were subjected to the same investigations and used as a comparison. Nano-indentation data were statistically analysed using the Student's t-test. RESULTS: XRD analysis on HyFlex EDM revealed the presence of martensite and rhombohedral R-phase, while a mixture of martensite and austenite structure was identified in HyFlex CM. DSC analysis also disclosed higher austenite finish (Af) temperatures for electro-discharge machining (EDM) instruments. Significant differences in nano-hardness and modulus of elasticity were found between EDM and CM files (P < 0.05). FE-SEM and EDS analyses confirmed that both new EDM and CM files were covered by an oxide layer. Micro-Raman spectroscopy assessed the presence of rutile-TiO2 . CONCLUSIONS: HyFlex EDM revealed peculiar structural properties, such as increased phase transformation temperatures and hardness. Present results corroborated previous findings and shed light on the enhanced mechanical behaviour of these instruments.

Double dye technique and fluid filtration test to evaluate early sealing ability of an endodontic sealer.

OBJECTIVES: The aim of the present study is to evaluate the possible correlation between sealer penetration into dentinal tubules and sealing ability both in presence and absence of smear layer. MATERIALS AND METHODS: Fourteen maxillary central incisors were treated with 5.25 % NaOCl +10 % EDTA to remove the smear layer (SL-free group) or 5.25 % NaOCl without EDTA (SL group). Root canals were filled using #25 Thermafil Obturators with Topseal sealer labelled with 0.1 wt% rhodamine B. Sealing ability was measured as fluid filtration rate with a fluid-flow meter using water supplemented with 0.3 % calcein fluorescent dye. Specimens were sectioned, observed under confocal microscope to co-localize the presence of sealer (rhodamine B labelling) into dentinal tubules and gaps (calcein labelling) into the root canal. The depth of sealer penetration into dentinal tubules and the percentage of sealer penetration around the root canal were measured at 3, 5 and 8 mm from the apex. RESULTS: No significant differences between groups were observed in fluid filtration rate nor in depth of calcein penetration. Sealer penetration depth and percentage into dentinal tubules were not significantly different between groups, except at 8-mm level in absence of smear layer. CONCLUSION: Sealer penetration at 3- and 5-mm levels was not influenced by smear layer while it was significantly reduced at 8-mm level. Fluid filtration rate was not correlated either with depth of calcein penetration nor with sealer penetration into dentinal tubules. CLINICAL RELEVANCE: The sealing ability of Topseal sealer is not affected by presence or absence of smear layer.

HyFlex EDM: superficial features, metallurgical analysis and fatigue resistance of innovative electro discharge machined NiTi rotary instruments.

AIM: To evaluate the surface and microstructural alterations of new and used HyFlex EDM prototypes and to test their fatigue resistance. METHODOLOGY: Fifteen HyFlex EDM prototypes were used for in vitro instrumentation of severely curved root canals. Surface and microstructural characteristics of new and used files were compared by ESEM analysis equipped with energy dispersive X-ray spectrophotometry (EDS) and optical metallographic imaging. Usage-induced degradation was assessed. Thirty additional HyFlex EDM prototypes and 20 standard manufactured HyFlex CM files were subjected to cyclic fatigue tests. Time to fracture was recorded, and results were validated using the Kruskal-Wallis test (α-level 0.05). Fatigued files were analysed by ESEM for fractographic evaluation. RESULTS: Surface and microstructural characterization of EDM prototypes revealed the typical spark-machined surface of a NiTi EDM alloy. No fractures were registered during root canal instrumentation. No evident surface alterations and minor degradation were observed between new and used instruments. The metallographic analysis of new and used files disclosed a homogeneous structure, mostly composed of lenticular martensite grains, and some residual austenite. The cyclic fatigue test showed an increase of fatigue resistance up to 700% on the EDM compared to CM files. CONCLUSIONS: Spark-machined peculiar surface is the main feature of HyFlex EDM. Low degradation was observed after multiple canal instrumentations. Prototypes exhibited surprising high values of cyclic fatigue resistance and a safe in vitro use in severely curved canals.

The effect of ultrasonic removal of various root-end filling materials.

AIM: To compare residual root-end filling material in apical root-end cavities following their removal with ultrasonic retrotips. METHODOLOGY: Thirty single-rooted teeth were filled with Thermafil and AH Plus sealer. Root-ends were resected at 90 degrees, 3 mm from the apex. Root-end cavities were prepared with diamond burs and ultrasonic retrotips and filled with one of three filling materials: group I: Retro-TC (calcium silicate-based cement), group II: IRM (Dentsply, Germany), group III: Vitrebond (3M ESPE, USA). After 30 days of storage, ultrasonic retrotips were used to remove materials from the root-end cavities. The ultrasonic application time was fixed at 60 s. Polyether impressions and replicas of the root-ends were made. Root apices and replicas were examined by one operator under a scanning electron microscope. Remnants of residual materials were evaluated using a four-level scoring system; fractures, smear layer and exposed dentinal tubules were also examined. RESULTS: Forty per cent of the specimens filled with Retro-TC revealed complete removal of the material with exposure of dentinal tubules, whilst 60% contained residual cement. Twenty per cent of specimens filled with IRM were completely devoid of material, whereas 80% had retained material. Ten per cent of specimens filled with Vitrebond retained a moderate amount of material whilst 90% had substantial retention of the material. Statistically significant differences were found (P < 0.05) amongst the three groups of materials. CONCLUSIONS: Retro-TC was successfully removed in 40% of cases using ultrasonics retrotips for 60 s, whereas IRM and Vitrebond specimens had evidence of retained material in 80% and 90% of all specimens respectively.

Acute interstitial nephritis associated with carbenicillin therapy.

Although acute interstitial nephritis has been documented during therapy with many antibiotics of the penicillin class, it has not previously been reported in association with carbenicillin therapy. We report here the case of a patient who developed the characteristic clinical features of this form of injury while receiving prolonged large doses of carbenicillin. Histologic examination confirmed the presence of a striking interstitial nephritis. Carbenicillin should be considered a potential cause of renal damage in patients who develop rash, eosinophilia, and microscopic hematuria in association with deterioration of renal function.

Nephrotic syndrome and immune complex glomerulonephritis associated with chlorpropamide therapy.

Therapeutic drugs are well-recognized as a cause of the nephrotic syndrome in humans. However, documentation of the renal histopathologic features is lacking or incomplete in many cases. Even when accurate histopathologic information is available, there is little evidence to support a specific pathogenetic mechanism of renal injury in the vast majority of cases. We describe a patient with diabetes who had hepatitis and dermatitis in association with the use of chlorpropamide. In addition to these well-described toxic reactions to this drug, the nephrotic syndrome developed. Renal biopsy revealed the presence of a proliferative glomerulonephritis that was shown to be of an immune complex nature on immunofluorescence and electronmicroscopic study. Serial serum complement levels and circulating immune complex levels were consistent with an immunologically mediated reaction. Repeated renal biopsy documented resolution of the renal changes. Thus, in this patient, a drug-induced nephrotic syndrome was associated with a proliferative glomerulonephritis, probably due to the formation of immune complexes.

Temporal arteritis and renal disease. Case report and review of the literature.

Renal abnormalities have been described in a small percentage of patients with temporal arteritis. Transient microscopic hematuria is the most common finding. In rare instances, widespread vasculitis involving renal arteries or microscopic polyarteritis nodosa can be seen. This case report describes the association of temporal arteritis with membranous glomerulonephropathy and the nephrotic syndrome in an elderly patient, an occurrence not previously reported. Whether this association is coincidental or pathogenetically linked remains to be determined.

Chronic membranoproliferative glomerulonephritis. A patient with recurrent episodes simulating rheumatic fever and acute nephritis.

A most unusual case of chronic membranoproliferative glomerulonephritis with nodule formation is reported in an elderly man in whom it was possible to document many episodes of acute oilguric and hemorrhagic glomerulonephritis and a syndrome resembling acute rheumatic fever. Severe renal failure necessitating peritoneal dialysis occurred on three occasions. Renal function returned to near preexacerbation levels in each episode. Although there was strong clinical evidence for streptococcal hypersensitivity, convincing laboratory documentation was lacking. The histologic and immunopathologic findings changed comparatively little during the several exacerbations. Impairment in fibrinolytic and coagulation activities by circulating macromolecular complexes is postulated for the induction and perpetuation of the glomerular injury.

Long-term follow-up of patients with lupus nephritis. A study based on the classification of the World Health Organization.

The long-term course of 56 patients with systemic lupus erythematosus who had precisely defined renal histology and carefully assessed clinical status at the time of their initial renal biopsy prior to 1976 was evaluated and analyzed by life-table analysis. The average length of follow-up has now been greater than 10 years since initial biopsy. Patients with mesangial lesions (World Health Organization [WHO] classes IIA and IIB) had a more favorable renal and patient survival at five and 10 years than did patients in the other WHO classes (III, IV, and V). Individual renal histologic features of activity and chronicity when combined into an activity index and a chronicity index did not significantly predict renal survival in this population, nor did the presence of hypertension or renal dysfunction at the time of the initial renal biopsy significantly influence renal or patient survival. Patients with the nephrotic syndrome at initial biopsy had a poorer renal survival than did patients without the nephrotic syndrome. However, patients who experienced a remission of the nephrotic syndrome fared better in terms of both renal and patient survival than did those patients without a remission. By life-table analysis, patient survival was significantly better for patients in whom biopsy was performed after 1973 than for those in whom biopsy was performed prior to that time despite similar clinical features and WHO histology in each group interval. Our data suggest that improved survival for patients in recent studies may relate to better supportive care and more selective use of immunosuppressive therapy in patients with milder forms of lupus nephritis.

Production of experimental toxemia in the pregnant dog.

The aortas of 14 pregnant bitches were treated 1 to 3 weeks before term, producing a stricture that reduced the lumen from an average normal of 7-11 mm to 2.1 mm in diameter. Nine animals developed hypertension, 3 had significant proteinuria, and 1 had fluid retention. Light microscopy revealed moderate or severe glomerular lesions in 9 animals characterized by endotlial cell swelling, mesangial cell proliferation, and focal basement membrane thickening; electron microscopy revealed mesangial enlargement and electron-dense deposits. Immunofluorescence with rabbit anti-dog fibrinogen showed glomerular deposition of fibrinogen or its breakdown products in 11 of 12 cases so studied. Focal necrosis was seen in the liver in 5 cases, and diffuse hemorrhagic infarction of the placenta was present in all animals. None of these changes was found in nonpregnant or in sham-operated controls.

Predictability of surgical response in renovascular hypertension.

One hundred sixteen patients underwent operation for renovascular hypertension from 1962 through 1975; 64% had aortorenal reconstruction and 36% had nephrectomy. Sixty-six percent were cured and 19% were improved. Rapid sequence intravenous pyelography, radioisotope renography, and renal arteriography were equal in ability to detect renovascular hypertension. Bilateral renal biopsy specimens had excellent prognostic value when performed in a graded semiquantitative manner. Plasma renin activity was the most consistently useful criterion for prediction of surgical cure if the following requirements were used: (1) elevated peripheral plasma renin activity, (2) elevated renin from the affected kidney, and (3) suppressed renin secretion from the contralateral kidney. An angiotensin II antagonist, saralasin acetate, used in six patients before operation in an attempt to identify those whose hypertension depended on angiotensin II activity, produced a depressor response correlating well with the surgical result.

Acute tubulo-interstitial nephritis from candida albicans with oliguric renal failure.

A patient developed candidemia after receiving steroids and antibiotics. Subsequently, acute oliguric renal failure occurred. Renal biopsy showed multiple cortical microabscesses. These contained encapsulated ovoid Candida, budding organisms, short hyphae, and polymorphs. Adjacent tubules showed disruption of the basement membrane, infiltration by polymorphs and necrosis. There was no evidence of pelvic-calyceal obstruction by bezoar. The acute renal failure was attributed to acute candidal tubulo-interstitial nephritis, and was successfully reversed with Amphotericin.

Intravenous pulse cyclophosphamide treatment of severe lupus nephritis: a prospective five-year study.

Despite its widespread use, there are only a few published studies of the use of intravenous high dose pulse cyclophosphamide in systemic lupus nephritis. There are few data about the long-term efficacy and safety of this form of therapy. This study evaluates the clinical efficacy, toxicity, and effects on renal morphology of this regimen in patients with severe lupus nephritis followed prospectively over a five-year period. Twenty consecutive patients with severe active lupus nephritis were enrolled in a treatment regimen of six monthly intravenous pulses of cyclophosphamide (0.5 to 1 g/m2) together with high dose corticosteroid therapy which was rapidly tapered. Efficacy was assessed by improvement or stabilization of clinical, serologic and renal functional parameters. Repeat renal biopsies were performed in 15 patients. Potential toxicity related to therapy was documented. Over the first six months of treatment, this regimen resulted in improvement of clinical activity, lupus serology, stabilization of renal function and decreased proteinuria in 19/20 patients. Nephrotic syndrome remitted in 8/10 patients by one year. Over five years of follow-up, there were five treatment failures defined as a doubling of serum creatinine over baseline. At five years, 3 patients required renal replacement therapy. Elevated plasma creatinine at time of first biopsy, degree of proteinuria, histologic activity and chronicity were not statistically correlated with treatment failure. Patients who failed to respond to this treatment were, however, more likely to have diffuse proliferative lupus nephritis (WHO Class IV) lesions on initial biopsy.(ABSTRACT TRUNCATED AT 250 WORDS)

Renal involvement in adult Gaucher's disease after splenectomy.

Gaucher's disease with severe clinical and pathologic renal involvement is exceptionally rare. This article describes severe renal involvement and proteinuria in a young black woman with Gaucher's disease. The accumulation of glucocerebroside (Gaucher bodies) in glomerular mesangial and endothelial cells and in interstitial cells of the kidney is indicative of the phagocytic potential and the deficiency of glucocerebroside-cleaving enzyme in these cells. Severe proteinuria in this patient was attributed to the extensive glomerular involvement by Gaucher's disease.

Tubular microfibrils in the glomeruli of membranous nephropathy.

The presence of tubular microfibrils in the mesangium and capillary walls of the renal glomeruli is a rare occurrence that has been reported by others in different glomerular disease processes. The two cases presented in this report demonstrated such microfibrils in membranous glomerulonephropathy, an association previously described in only one other case. These microfibrils differed in size and structural characteristics from collagen fibers, amyloid fibrils, and cryoglobulin microtubules.

Chronic interstitial nephritis associated with gold therapy.

A patient suffered chronic interstitial nephritis after receiving large quantities of gold salts for rheumatoid arthritis. Gold deposits were seen with transmission electron microscopy and confirmed by microprobe x-ray analysis both within renal tubular epithelial cells and interstitial macrophages and free within the renal interstitium. Clinical resolution of renal failure followed discontinuation of therapy with gold salts. Probable mechanisms of injury to renal tubular epithelial cells include uptake of gold by tubular epithelial cells and incorporation of gold into mitochondria, with subsequent cellular injury; interstitial deposits probably occur after necrosis of tubular epithelial cells, with release of gold into the interstitium and resultant inflammation. Thus, chronic interstitial nephritis can be added to the patterns of renal injury seen after gold therapy for rheumatoid arthritis.

The use of calcium-silicate cements to reduce dentine permeability.

OBJECTIVE: To evaluate in vitro the effectiveness of different calcium-silicate (CS) cements specifically designed for dentine permeability reduction. DESIGN: Fifty dentine discs were prepared from caries free human molars extracted for surgical reasons. The treatment consisted in applying two different experimental CS cements on dentine surface. Dentine discs treated only with EDTA served as negative control group. Treatment with D-Sense Crystal and Clearfil S(3)-Bond served as positive control groups. After treatment samples were immersed in artificial saliva. The quantitative changes in the hydraulic conductance (i.e. permeability) through dentinal tubules were quantified using a hydrostatic device working at 6.9 kPa. Dentine permeability was measured immediately after EDTA treatment, 10 min and 1 week after treatment application and immersion of dentine samples in artificial saliva. SEM/EDX analyses were performed to obtain qualitative information on dentine morphology and surface deposits. RESULTS: The experimental CS cements reduced dentine permeability immediately after application and also 10 min and 1 week after the immersion of the specimens in artificial saliva. D-Sense Crystal and Clearfil S(3)-Bond showed higher levels of dentine permeability after 1 week of immersion in artificial saliva. CONCLUSIONS: CS cements reduced dentine permeability in vitro even after immersion in artificial saliva, which makes them new valuable candidates for treatment of dentine hypersensitivity in vivo.