Methods for measurement of root canal curvature: a systematic and critical review.

The assessment of root canal curvature is essential for clinical and research purposes. This systematic review presents an overview of the published techniques for the measurement of root canal curvature features using imaging and to provide a critique of their clinical application. A database search in PubMed, PubMed Central, Embase, Scopus, EBSCO Dentistry & Oral Sciences Source and Virtual Health Library was conducted, using appropriate key words to identify measurement methods for root canal curvatures. The search strategy retrieved 10594 records in total, and 31 records fulfilled the inclusion criteria. From 2D image acquisitions, eleven studies measured exclusively the angle of curvature, an additional thirteen measured other curvature features (level, height, radius, length and shape). Seven reports described methods from 3D imaging (CBCT, µCT). Root canal curvatures should be measured, for clinical proposes, to facilitate endodontic treatment planning, and in research, to reduce the risk of selection bias. This review has revealed that there are many methods described in the literature; however, no consensus exists on which method should be used. Some of the methodologies have potential clinical translation, whereas others are suitable for research purpose only, as they require a specific software or radiographic exposure in the mesiodistal direction.

Influence of apical enlargement on the repair of apical periodontitis in rats.

AIM: To evaluate the influence of different apical enlargement protocols on the radiographic and histological healing of apical periodontitis in rats. METHODOLOGY: Apical periodontitis was induced bilaterally in the mandibular right and left first molars of 24 Wistar rats by pulp exposure to the oral cavity for 3 weeks. A standard serial root canal preparation technique was performed in the molar of one side, whilst the opposite side was the control group. Rats were randomly divided into three experimental groups (n = 8), according to the diameter of apical enlargement during root canal preparation: K-files size 20 (EG1), size 25 (EG2) and size 30 (EG3). Each animal was its own positive control, because the opposite arch remained untreated. Root canals were filled with a standard technique. After 3 weeks, the animals were euthanized. The main outcome of apical periodontitis healing was evaluated radiographically (mm2 ) and histologically (ordinal scores of inflammation) using a HE staining technique. The measurement of effect was obtained between the three experimental groups by carrying out generalized estimating equations, with Poisson regression with robust variance, pairing each experimental group with its respective control group within animals, adjusted for the mean within animal differences, with α = 5%. RESULTS: The mean and standard deviations of radiographic apical periodontitis size (mm2 ) and intensity of histological inflammatory scores were, respectively: EG1 (0.44 ± 0.27; 2.25 ± 0.46), EG2 (0.33 ± 0.10; 2.50 ± 0.53) and EG3 (0.22 ± 0.08; 2.63 ± 0.74). After 3 weeks, a significantly more favourable radiographic repair was observed when larger apical enlargement was performed (EG3), compared to EG1 and EG2 (P = 0.001). All experimental groups were associated with a significant difference on the radiographic and histological healing of apical periodontitis compared with its respective control group. CONCLUSION: Under the experimental conditions of this study, a larger apical enlargement protocol favoured a more rapid radiographic repair of apical periodontitis in rats after a 3-week follow-up.

Association of manual or engine-driven glide path preparation with canal centring and apical transportation: a systematic review.

The role and effect of glide path preparation in root canal treatment remain controversial. This systematic review aims to compare apical transportation and canal centring of different glide path preparation techniques, with or without subsequent engine-driven root canal preparation. A database search in PubMed, PubMed Central, Embase, Scopus, EBSCO Dentistry & Oral Sciences Source and Virtual Health Library was conducted, using appropriate key words to identify the effect of glide path preparation (or its absence) on apical transportation and canal centring. An assessment for the risk of bias in included studies was carried out. Amongst 2146 studies, 18 satisfied the inclusion criteria. Nine studies assessed glide path preparation per se, comparing apical transportation and canal centring of rotary systems and/or manual files; eleven further investigations examined the efficacy of the glide path prior to final canal preparation with different engine-driven systems. Risk of bias and other study design features with potential influence on study outcomes and clinical implications were assessed. Based on the available evidence, and within the limitation of the studies included, preparation of a glide path using rotary sequences performs similarly (in most of the component studies) or significantly better than manual preparation when assessing apical transportation or canal centring. When compared to the absence of a glide path, canal shaping following glide path preparation was of similar, or significantly better quality, in regard to apical transportation or canal centring.

Acute coronary artery thrombosis in paroxysmal nocturnal hemoglobinuria.

We have reported a case of coronary artery thrombosis in a 36-year-old man with paroxysmal nocturnal hemoglobinuria (PNH), a potentially lethal thrombotic complication not previously documented in this unique patient population. Although the etiology of PNH remains unknown, the pathogenesis appears to be related to the deficiency of a specific membrane complement-regulatory protein, decay accelerating factor. Coronary artery thrombosis must now be added to the list of potential life-threatening thrombotic complications.

A new gene deletion in the alpha-like globin gene cluster as the molecular basis for the rare alpha-thalassemia-1(--/alpha alpha) in blacks: HbH disease in sickle cell trait.

A novel deletion of at least 26 kilobase of DNA, including both alpha-globin genes, the psi alpha- and psi zeta-globin genes, but sparing the functional zeta-gene was found in a 10-year-old black boy with HbH disease and sickle cell trait. This particular deletion has not previously been described in blacks. Its existence makes it likely that the absence of Hb Barts hydrops fetalis in blacks is due to the rarity of the chromosome lacking two alpha-globin genes rather than a result of early embryonic death due to the failure to synthesize embryonic hemoglobins because of deletion of functional zeta-globin genes.

Angioid streaks associated with hereditary spherocytosis.

We examined members of a family in whom hereditary spherocytosis had appeared in three generations. Angioid streaks were confirmed in the second generation and presumed to exist in the first generation. A woman in the third generation with hereditary spherocytosis did not have angioid streaks but these are age-related and may develop later. The one individual in the second generation without hereditary spherocytosis did not have angioid streaks. Angioid streaks associated with hereditary spherocytosis in this family did not appear to be coincidental. Patients with hereditary spherocytosis should be examined for angioid streaks because of the implications for their vision.

Endotoxin-mediated inhibition of human platelet aggregation.

A variety of endotoxins, when added to human platelet-rich plasma (PRP) or to suspensions of washed platelets (WP), demonstrated an inhibitory effect on platelet aggregation induced by various aggregating agents. Endotoxin blocked the release of 14C serotonin from platelets but had no influence on cyclic AMP production. Endotoxin did not interfere with thromboxane generation by platelets. However, endotoxin-treated platelets failed to respond to added thromboxane. The inhibitory effect of endotoxin on platelet aggregation was more pronounced in the presence of ionophore A23187 as compared to other aggregating agents and was effectively reversed by calcium but not by magnesium, another divalent cation. Furthermore, endotoxin failed to inhibit the ristocetin-induced agglutination of formaldehyde-fixed platelets; a non-calcium dependent phenomenon. These findings appear to suggest that endotoxin-mediated inhibitory activity of platelet aggregation is related to the interference in the role of calcium. The antiaggregatory activity of endotoxin appears to be due to a direct and rapid action on platelets and not due to a non-specific binding, as the effect was not abolished by washing the endotoxin-incubated platelets. Endotoxin-mediated alteration of platelet function may contribute to bleeding diathesis in septecemic and endotoxemic patients.

Spontaneous rupture of the spleen: an unusual presenting feature in Hodgkin's lymphoma.

"Spontaneous" (pathologic) rupture of the spleen is a rare phenomenon in lymphomas, 11 cases appearing in the English language literature. We describe the second case of Hodgkin's disease in which the initial presentation was spontaneous splenic rupture. The occurrence of splenic rupture in lymphomas seems to carry a bad prognosis since it is likely to reflect stage IV disease whether manifest before the rupture or soon thereafter.

Perioperative management of patients with paroxysmal nocturnal hemoglobinuria.

During the past two decades, we have had the opportunity to study a large number of patients with the rare hemolytic anemia, paroxysmal nocturnal hemoglobinuria. Sixteen surgical procedures have been performed upon ten patients with paroxysmal nocturnal hemoglobinuria. From this experience, we have developed certain recommendations for preoperative evaluation and preparation, intraoperative management and post-operative care. Any proposed surgical procedure for a patient with paroxysmal nocturnal hemoglobinuria should be closely managed by a team consisting of a surgeon, hematologist and anesthesiologist. In the preoperative evaluation, particular attention should be paid to the hematologic, renal and hepatic status. Transfusion requirements, whether precipitated by hemolytic episodes or surgical blood loss, should be met with either washed or perviously frozen erythrocytes, with consideration of the use of dextran for volume replacement. Dextran is the treatment of choice for thrombotic epidsodes. Close attention should be given to avoiding hypoxia and dehydration. Anesthetic agents which may activate complement or may be hepatotoxic are to be avoided.

The kidneys in paroxysmal nocturnal hemoglobinuria.

Long-term study of 21 PNH patients revealed an unexpectedly high incidence of functional and anatomic renal abnormalities. Most patients demonstrated varying degrees of hematuria and proteinuria distinct from hemoglobinuria. Evaluation of renal function revealed hyposthenuria, abnormal tubular function, and declining creatinine clearance. Radiologically these patients had enlarged kidneys, cortical infarcts, cortical thinning, and papillary necrosis which were confirmed by autopsy studies. Hypertension developed in eight patients. Urinary tract infection was uncommon. The renal findings bear striking similarity to those of sickle cell anemia. Contrary to the usual opinion, out studies clearly showed evidence of widespread renal pathology in PNH most likely due to repeated microvascular thrombosis similar to the venous thrombosis involving other organs in this disorder.

Fulminant hepatic venous thrombosis (Budd-Chiari syndrome) in paroxysmal nocturnal hemoglobinuria: definition of a medical emergency.

Hepatic venous thrombosis (HVT) should be recognized as a distinct and highly lethal thrombotic complication of paroxysmal nocturnal hemoglobinuria. In a patient with fulminant onset prompt recognition of a triad of clinical, laboratory and liver scan findings facilitated early, aggressive and prolonged heparinization followed by coumadin maintenance, all with good results. Additionally a case of asymptomatic, smoldering HVT was unearthed by liver scan survey and confirmed by hepatic venogram; the patient was started on a regimen of Coumadin (crystalline sodium warfarin, Endo).

Heparin neutralization of PGI2: effects upon platelets.

Heparin neutralizes the inhibitory effect of prostacyclin (PGI2) on platelet aggregation. The PGI2-induced enhancement of platelet cyclic adenosine monophosphate levels is also inhibited. The mechanism appears to involve a direct interaction in which heparin neutralizes the inhibitory effects of PGI2 on platelet aggregation but, at the same time, does not lose its own anticoagulant activity. These findings may explain instances in which heparin infusions have been reported to produce hyperaggregation of platelets, thrombotic episodes, and thrombocytopenia in patients.

Hemophilus influenzae septicemia and polyarthritis in multiple myeloma.

Hemophilus influenzae sepsis, rare in adults, is reported for the first time in association with multiple myeloma. The patient developed fulminant septicemia involving multiple organs and disabling pyarthrosis due to nonencapsulated H influenzae, usually considered to be nonpathogenic. Early diagnosis and appropriate antibiotic therapy cured the infection and prevented permanent joint disease. Also illustrated is the problem of establishing a diagnosis of myclomatosis in patients with septicemia. The English language literature on H influenzae sepsis and polyarthritis in association with myeloma has been reviewed.

Combination chemotherapy and radiation therapy of undifferentiated small cell bronchogenic carcinoma.

We reviewed 76 cases of small cell bronchogenic carcinoma seen at the University of South Florida Medical Center. One third of the 55 patients who have subsequently died did so within one month of diagnosis. Thirty-five patients were treated with cyclophosphamide, adriamycin, vincristine, and radiation therapy including prophylactic cranial irradiation. Of these 35 patients, 40% demonstrated a complete remission for a total objective response rate of 63%. The projected median survival of patients referred for study is 14 months. Improved survival was found in patients less than 60 years of age, with limited disease, who responded to treatment and in whom there were no violations of protocol. Patients treated with combination therapy appear to survive longer than untreated patients and those treated with radiation therapy alone. Toxicity was tolerable and there were no deaths related to treatment. Small cell bronchogenic carcinoma is a rapidly progressive systemic disease responsive to multimodality therapy with long-term survival in some patients.