Sellado marginal aplicando hipoclorito de sodio versus ácido fosfórico como acondicionador dental / Marginal sealing applying sodium hypochlorite versus phosphoric acid as dental conditioner

RESUMEN Introducción: La microfiltración es uno de los problemas principales de todas las obturaciones a base de resina. Muchos estudios buscan optimizar un buen sellado marginal utilizando diversos acondicionadores, como el hipoclorito de sodio, que permite que el adhesivo penetre bien, al generar desproteinización, y el ácido fosfórico que permite remover el barro dentinario, y así de esta manera formar una capa híbrida al colocar el adhesivo. Objetivo: Evaluar el grado de sellado marginal de la resina Bulk Fill aplicando gel de hipoclorito de sodio 10 por ciento comparado con el gel de ácido fosfórico al 37 por ciento en el acondicionamiento dental in vitro. Métodos: El universo fue de 72 dientes con cavidades clase I; se separaron en 4 grupos por muestra de 18 dientes cada uno; después de obturar se realizó el termociclaje a 500 ciclos entre 5 °C a 55 °C; luego se sumergieron en azul de metileno 2 por ciento, durante 12 h y 24 h a temperatura de 37 °C. Finalmente se evaluó el sellado marginal en el estereomicroscopio, según el ISO / TS 11405: 2015, con los criterios siguientes: grado 0 (sin microfiltración), grado 1 (microfiltración hasta esmalte), grado 2 (microfiltración hasta dentina) y grado 3 (microfiltración hasta piso pulpar). Resultados: El acondicionamiento con ácido fosfórico 37 por ciento a las 12 h presentó grado 0 (55,6 por ciento) y grado 1 (33,3 por ciento), y a las 24 h, grado 1 (55,6 por ciento). Con respecto al hipoclorito de sodio 10 por ciento a las 12 h, grado 0 (44.4 por ciento) y a las 24 h predominó grado 1 (55,6 por ciento). Para la contrastación de hipótesis en muestras relacionadas se obtuvo en ácido fosfórico 37 por ciento e hipoclorito de sodio al 10 por ciento a las 12 h y 24 h un p= 0,052 y p= 0,584, respectivamente. Para comparaciones entre muestras independientes a las 12 h y 24 h se obtuvo p= 0,462 y p= 0,406, respectivamente. Conclusiones: El gel de hipoclorito de sodio al 10 por ciento presenta similar eficacia en el sellado marginal respecto al gel de ácido fosfórico al 37 por ciento, al utilizarlo como acondicionador dental(AU)

ABSTRACT Introduction: Microfiltration is one of the main problems of all resin sealings. Many studies aim to optimize marginal sealing using a variety of conditioners, such as sodium hypochlorite, which allows good penetration of the adhesive by generating deproteinization, and phosphoric acid, which allows removal of the dental smear layer, thus creating a hybrid layer when the adhesive is placed. Objective: Evaluate the marginal sealing degree of Bulk Fill resin applying 10 percent sodium hypochlorite gel versus 37 percent phosphoric acid gel in in vitro dental conditioning. Methods: The study universe was 72 teeth with class I cavities, divided into four groups of 18 teeth. Upon sealing, thermal cycling was performed at 500 cycles from 5 ºC to 55 ºC. Next the teeth were submerged in 2 percent methylene blue for 12 h and 24 h at a temperature of 37 ºC. Finally marginal sealing was evaluated in the stereo microscope according to ISO / TS 11405: 2015, using the following scale: grade 0 (no microfiltration), grade 1 (microfiltration as far as the enamel), grade 2 (microfiltration as far as the dentin), and grade 3 (microfiltration as far as the pulp floor). Results: Conditioning with 37 percent phosphoric acid was grade 0 (55.6 percent) and grade 1 (33.3 percent) at 12 h, and grade 1 (55.6 percent) at 24 h, whereas conditioning with 10 percent sodium hypochlorite was grade 0 (44.4%) at 12 h, and predominantly grade 1 (55.6 percent) at 24 h. Hypothesis contrast in related samples yielded 37 percent phosphoric acid and 10 percent sodium hypochlorite at 12 h and 24 h, p= 0.052 and p= 0.584, respectively. Comparison between independent samples at 12 h and 24 h yielded p= 0.462 and p= 0.406, respectively. Conclusions: The 10 percent sodium hypochlorite gel has similar marginal sealing effectiveness as the 37 percent phosphoric acid gel when used as dental conditioners(AU)

Intracellular metabolism and potential cardiotoxicity of a ß-D-2'-C-methyl-2,6-diaminopurine ribonucleoside phosphoramidate that inhibits hepatitis C virus replication.

ß-D-2'-C-Methyl-2,6-diaminopurine ribonucleoside (2'-C-Me-DAPN) phosphoramidate prodrug (DAPN-PD) is a selective hepatitis C virus inhibitor that is metabolized intracellularly into two active metabolites: 2'-C-Methyl-DAPN triphosphate (2'-C-Me-DAPN-TP) and 2'-C-methyl-guanosine 5'-triphosphate (2'-C-Me-GTP). BMS-986094 and IDX-184 are also bioconverted to 2'-C-Me-GTP. A phase IIb clinical trial with BMS-986094 was abruptly halted due to adverse cardiac and renal effects. Herein, we developed an efficient large scale synthesis of DAPN-PD and determined intracellular pharmacology of DAPN-PD in comparison with BMS-986094 and IDX-184, versus Huh-7, HepG2 and interspecies primary hepatocytes and human cardiomyocytes. Imaging data of drug treated human cardiomyocytes was found to be most useful in determining toxicity potential as no obvious beating rate change was observed for IDX-184 up to 50 µM up at 48 h. However, with BMS-986094 and DAPN-PD at 10 µM changes to both beat rate and rhythm were noted.

Phase I Study of CTT1057, an 18F-Labeled Imaging Agent with Phosphoramidate Core Targeting Prostate-Specific Membrane Antigen in Prostate Cancer.

Agents targeting prostate-specific membrane antigen (PSMA) comprise a rapidly emerging class of radiopharmaceuticals for diagnostic imaging of prostate cancer. Unlike most other PSMA agents with a urea backbone, CTT1057 is based on a phosphoramidate scaffold that irreversibly binds to PSMA. We conducted a first-in-humans phase I study of CTT1057 in patients with localized and metastatic prostate cancer. Methods: Two patient cohorts were recruited. Cohort A patients had biopsy-proven localized prostate cancer preceding radical prostatectomy, and cohort B patients had metastatic castration-resistant prostate cancer. Cohort A patients were imaged at multiple time points after intravenous injection with 362 ± 8 MBq of CTT1057 to evaluate the kinetics of CTT1057 and estimate radiation dose profiles. Mean organ-absorbed doses and effective doses were calculated. CTT1057 uptake in the prostate gland and regional lymph nodes was correlated with pathology, PSMA staining, and the results of conventional imaging. In cohort B, patients were imaged 60-120 min after injection of CTT1057. PET images were assessed for overall image quality, and areas of abnormal uptake were contrasted with conventional imaging. Results: In cohort A (n = 5), the average total effective dose was 0.023 mSv/MBq. The kidneys exhibited the highest absorbed dose, 0.067 mGy/MBq. The absorbed dose of the salivary glands was 0.015 mGy/MBq. For cohort B (n = 15), CTT1057 PET detected 97 metastatic lesions, and 44 of 56 bone metastases detected on CTT1057 PET (78.5%) were also detectable on bone scanning. Eight of 32 lymph nodes positive on CTT1057 PET (25%) were enlarged by size criteria on CT. Conclusion: CTT1057 is a promising novel phosphoramidate PSMA-targeting 18F-labeled PET radiopharmaceutical that demonstrates similar biodistribution to urea-based PSMA-targeted agents, with lower exposure to the kidneys and salivary glands. Metastatic lesions are detected with higher sensitivity on CTT1057 imaging than on conventional imaging. Further prospective studies with CTT1057 are warranted to elucidate its role in cancer imaging.

Effect of a novel quaternary ammonium silane on dentin protease activities.

OBJECTIVES: Demineralized dentin collagen release C-terminal cross-linked telopeptide (ICTP) and C-terminal peptide (CTX) during degradation. The present study evaluated the effects of dentin pre-treatment with K21, a quaternary ammonium silane (QAS), on matrix metalloproteinase (MMP) and cathepsin K-mediated collagen degradation. METHODS: Dentin beams were demineralized with 10% H3PO4 for 24h. After baseline dry mass measurements, the beams were divided into 5 groups (N=10) according to protease inhibitors. The beams were pre-treated for 2min with 2% chlorhexidine (CHX), 2%, 5% or 10% QAS; no pre-treatment was performed for the control group. The beams were subsequently incubated in calcium- and zinc-containing medium for 3, 7 or 14days, after which changes in dry mass were measured and incubation media were examined for ICTP and CTX release. The MMP-2 and cathepsin K activities in QAS-treated dentin powder were also quantified using ELISA. RESULTS: The two factors (disinfectants and time) had a significant effect on dry mass loss, ICTP and CTX release (p<0.001). The percentage of dry mass loss increased with time and was significantly lower in all experimental groups when compared to the control at 14days (p<0.001). Conversely, the rate of ICTP and CTX release was significantly lower in the experimental groups, compared to the uninhibited control at 7 and 14days (p<0.001). Dentinal MMP-2 and cathepsin K activities were significantly reduced after demineralized dentin was pre-treated with QAS. CONCLUSION: The experimental QAS is a good inhibitor of MMP and cathepsin K activities in demineralized dentin. CLINICAL SIGNIFICANCE: The newly developed antibacterial quaternary ammonium silane increases the resistance of dentin collagen to degradation by inhibiting endogenous matrix metalloproteinases and cysteine cathepsins. The quaternary ammonium silane cavity disinfectant is promising for use as a protease inhibitor to improve durability of resin-dentin bonds.

NaF Inhibits Matrix-Bound Cathepsin-Mediated Dentin Matrix Degradation.

Matrix metalloproteinases (MMPs) and cysteine cathepsins (CCs) degrade the collagen fibrils of demineralized dentin. Sodium fluoride (NaF) has previously been shown to inhibit recombinant MMP-2 and MMP-9. This study aimed to evaluate the efficacy of NaF on the inhibition of dentin-bound MMPs and CCs. Dentin beams were completely demineralized in 10% phosphoric acid. The baseline total MMP activity and dry masses were measured. Beams were assigned to test groups based on similar MMP activity and dry mass (n = 10/group), and incubated in artificial saliva (control) or artificial saliva with NaF containing 6-238 mM fluoride for 1, 7 and 21 days. The dry mass loss and MMP activities were reassessed at each time point. The proteolytic activity was screened by gelatin zymography. ICTP and CTX released to the incubation medium were analyzed as indices of MMP and cathepsin K activity, respectively. The beams were examined under scanning electron microscopy. All NaF doses reduced the dry mass loss after 21 days (p < 0.05). NaF inhibition of the total MMP activity ranged between 5 and 80%. In gelatin zymography, the bands of MMP-2 and MMP-9 became less prominent with increasing NaF levels. NaF did not decrease the released ICTP (p > 0.05). Less CTX release was detected with F ≥179 mM (p < 0.05). CaF2-like minerals were observed on the beams. High levels of NaF may slow the degradation of the dentin matrix due to the inhibition of cathepsin K. Fluoride does not seem effective in the direct inhibition of proteolysis by dentin matrix-bound MMPs.

Development and characterization of chemical cochleostomy in the Guinea pig.

OBJECTIVES: Creation of an atraumatic, hearing-preservation cochleostomy is integral to the future of minimally invasive inner ear surgery. The goal of this study was to develop and characterize a novel chemical approach to cochleostomy. STUDY DESIGN: Prospective animal study. SETTING: Laboratory. METHODS: Experimental animal study in which phosphoric acid gel (PAG) was used to decalcify the otic capsule in 25 Hartley guinea pigs. Five animals in each of 5 surgical groups were studied: (1) mechanically opening the auditory bulla alone, (2) PAG thinning of the basal turn otic capsule, leaving endosteum covered by a layer of bone, (3) micro-pick manual cochleostomy, (4) PAG chemical cochleostomy, exposing the endosteum, and (5) combined PAG/micro-pick cochleostomy, with initial chemical thinning and subsequent manual removal of the last osseous layer. Preoperative and postoperative auditory brainstem responses and otoacoustic emissions were obtained at 2, 6, 10, and 16 kHz. Hematoxylin and eosin-stained paraffin sections were compared. RESULTS: Surgical and histologic findings confirmed that application of PAG provided reproducible local bone removal, and cochlear access was enabled. Statistically significant auditory threshold shifts were observed at 10 kHz (P = .048) and 16 kHz (P = .0013) following cochleostomy using PAG alone (group 4) and at 16 kHz using manual cochleostomy (group 3) (P = .028). No statistically significant, postoperative auditory threshold shifts were observed in the other groups, including PAG thinning with manual completion cochleostomy (group 5). CONCLUSION: Hearing preservation cochleostomy can be performed in an animal model using a novel technique of thinning cochlear bone with PAG and manually completing cochleostomy.

Oral tissues and orthodontic treatment: common side effects.

The aim of this paper was to provide a literature review about the problems that can occur during orthodontic treatment. Using the PubMed database we collected items that would provide information regarding the direct consequences of the placement of an orthodontic appliance: coming to the discussion of the following topics: candida infections, the effects on the soft tissues, the effects on periodontal tissues and effects on hard tissues. The presence of appliances in the oral cavity increases the prevalence of people with candida, specifically the species Candida Albicans is the most frequently isolated. The balance between the clearance of the microorganism, the colonization and the state of candidiasis depends both on the virulence of the fungus, and the competence of the host immune system. On soft tissues, cases of ulceration of the upper jaw by a rapid palatal expander and pyogenic granuloma due to quad helix appliance have been reported. The second one is mostly observed on vestibular gingiva. The first one was found, however, in patients suffering from diabetes mellitus type 1 because of the tissue modifications induced by this pathological condition. The more severe periodontic effects are those caused by incorrect use of orthodontic elastic separators. Finally, the White Spot Lesions are the direct consequences of a wrong conditioning of enamel when attaching the bracket. They represent a first stage of caries in the positioning area of the bracket. The orthodontist is required to intercept these issues not to affect the success of the treatment.

Effect of phosphoric acid etching on the shear bond strength of two self-etch adhesives

Objective: To evaluate the effect of optional phosphoric acid etching on the shear bond strength (SBS) of two self-etch adhesives to enamel and dentin. Material and Methods: Ninety-six bovine mandibular incisors were ground flat to obtain enamel and dentin substrates. A two-step self-etch adhesive (FL-Bond II) and a one-step self-etch adhesive (BeautiBond) were applied with and without a preliminary acid etching to both the enamel and dentin. The specimens were equally and randomly assigned to 4 groups per substrate (n=12) as follows: FL-Bond II etched; FL-Bond II un-etched; BeautiBond etched; BeautiBond un-etched. Composite cylinders (Filtek Z100) were bonded onto the treated tooth structure. The shear bond strength was evaluated after 24 hours of storage (37°C, 100% humidity) with a testing machine (Ultra-tester) at a speed of 1 mm/min. The data was analyzed using a two-way ANOVA and post-hoc Tukey's test with a significance level of p<0.05. A field emission scanning electron microscope was used for the failure mode analysis. Results: Both adhesives evidenced a significant decrease in the dentin SBS with the use of an optional phosphoric acid-etching step (p<0.05). Preliminary phosphoric acid etching yielded significantly higher enamel SBS for FL-Bond II (p<0.05) only, but not for BeautiBond. FL-Bond II applied to un-etched dentin demonstrated the highest mean bond strength (37.7±3.2 MPa) and BeautiBond applied to etched dentin showed the lowest mean bond strength (18.3±6.7 MPa) among all tested groups (p<0.05). Conclusion: The use of a preliminary acid-etching step with 37.5% phosphoric acid had a significant adverse effect on the dentin bond strength of the self-etch adhesives evaluated while providing improvement on the enamel bond strength only for FL-Bond II. This suggests that the potential benefit that may be derived from an additional etching step with phosphoric acid does not justify the risk of adversely affecting the bond strength to dentin.

Lesiones de la mucosa oral ocasionadas por materiales de uso odontológico / Oral mucosal lesions caused by dental materials

Existe una gran cantidad de patologías que asientan sobre la mucosa bucal, cuyo origen está relacionado con materiales o instrumental utilizado durante la práctica odontológica diaria. Ellas van desde erosiones hasta ulceraciones o lesiones crónicas como las pigmentaciones y leucoplasias, entre otras. En este trabajo se propone una clasificación de estas lesiones según su etiopatogenia

Influência da aplicaçäo de fluoreto em esmalte sobre a resistência de uniäo ao cisalhamento e a permeabilidade marginal da restauraçäo de compósito / Influence of the floride use in the retention of composite on tooth structure, marginal permeability, and with shear bond strength of composite into enamel

Graças ao advento do condicionamento ácido, condicionar as superfícies que seräo restauradas com compósito é essencial para se alcançar uma perfeita adesäo entre o compósito e a estrutura dentária. Ocorre uma grande preocupaçäo em relaçäo à remineralizaçäo das áreas quimicamente alteradas pelo ácido fosfórico. Existem vários trabalhos sobre o uso de fluoreto na técnica do condicionamento ácido, porém ocorre uma estreita correlaçäo entre a adesäo do compósito com a estrututa dentária, e a concentraçäo de fluoreto no dente. Esta pesquisa verificou se a incorporaçäo desse fluoreto interfere na retençäo do compósito à estrutura dentária (permeabilidade marginal) e na resistência ao cisalhamento de colagem do compósito em esmalte. Foram realizadas cavidades e com 3mm de diâmetro e 2mm de profundidade em dentes bovinos, as quais foram condicionadas com as seguintes soluçöes: a) ácido fosfórico à 35 por cento (grupo controle), b) ácido fosfórico à 35 por cento com 0,02 por cento de NaF (grupo I); c) ácido fosfórico à 35 por cento com 0,2 por cento NaF (grupo II), d) ácido fofórico com 0,5 por cento de NaF (grupo III); e) ácido fosfórico à 35 por cento seguido de aplicaçäo no esmalte de FFA 1,23 por cento (grupo IV). Procedeu-se à lavagem, secagem, aplicaçäo de adesivo Single bond (3M) e restauraçäo das cavidades, segundo as orientaçöes do fabricante. A permeabilidade foi avaliada, através do método de aplicaçäo do nitrato de prata, e observada em microscópio óptico (15x). Os resultados mostraram microinfiltraçäo em todos os grupos. Os valores dos grupos tratados com fluoreto foram significativamente superiores em relaçäo aos dos grupos controle, exceto o grupo I. No ensaio de resistência mecânica ao cisalhamento o esmalte bovino foi condicionado com as soluçöes relatadas acima, no teste de permeabilidade (grupos controle I, II, III, IV), procedeu-se à lavagem, secagem, aplicaçäo do adesivo Single bond e a construçäo de clindros de compósito com 3mm de diâmetro e 2mm de comprimento sobre o esmalte. Os resultados do ensaio de cisalhamento mostraram que os grupos tratados com condicionamento ácido contendo fluoreto até 0,2 por cento näo apresentaram diferença estatisticamente significativa em relaçäo ao grupo controle. Em funçäo dos resultados obtidos na presente pesquisa, sugere-se o emprego de condicionamento ácido com no máximo até 0,02 por cento de fluoreto de sódio

Avaliaçäo clínica e histopatológica da polpa dental de humanos jovens 60 dias após seu condicionamento com ácido fosfórico a 37 por cento e colocaçäo de um sistema adesivo de quarta geraçäo sobre a área da exposiçäo / The clinical and histopathologic evaluation of the young human dental pulp 60 days after 37 per cent phosphoric acid action's and phacement of on adhesive system of the fourth generation in an exposition area

Neste trabalho, os autores observaram a açäo do ácido fosfórico a 37 por cento de um sistema adesivo em contato íntimo com a polpa de humanos jovens. Análise clínica e histopatológica, 60 dias após, constatou-se ausência de infiltraçäo com discreta fibrose na área de exposiçäo

[Soft-drinks and health]. / Los refrescos y la salud.

OBJECTIVE: To analyze published papers about soft drinks use, and to describe possible health benefits, risks, and damages related to soft drink consumption. INFORMATION SOURCE: A search was done in the MEDLINE compact disks, from January 1970 to January 1997, with the keywords soft drink, beverages, carbonated beverages, cola, Coca-Cola and sweetening-agents. STUDY SELECTION: Ninety nine papers reporting health-related damages or benefits in clinical or experimental studies were reviewed. DATA EXTRACTION: All articles with a clear description of at least one beneficial or harmful effect related to soft drink consumption were considered. RESULTS: There were reports on 25 harmful effects and of 7 possibly beneficial effects. Data are classified in prophylactic and therapeutic uses, dental caries and other dental disorders, mineral metabolism disorders, acid-peptic disease, neoplasm, risk factors for cardiovascular disease, effects on central nervous system, reproduction, allergy, and miscellaneous. CONCLUSIONS: High prevalence of exposure and excessive consumption of soft drinks may represent a public health problem in Mexico. Data analysis shows that soft drink consumption may not be as harmless as generally believed. Many of the reports are anecdotal, without a suitable methodological design. A wide field for research is present in this area.

Avaliaçäo da efetividade de agentes condicionadores ácidos em diferentes tempos de observaçäo, com e sem contaminaçäo pela saliva / Effectiveness of etching agents to enamel in different observation times, with and without saliva contamination

Verificou-se, por meio de testes de resistência ao cisalhamento, a efetividade de retençäo da resina composta Herculite XR ao esmalte dental, conseguida pelo condicionamento ácido, e a influência da contaminaçäo pela saliva durante 1 minuto. Cento e quarenta dentes permanentes humanos extraídos foram condicionados durante 15, 30 e 60 segundos com ácido fosfórico a 37 por cento em gel e durante 1 e 2 minutos com o oxalato de potássio a 3 por cento em gel e em soluçäo. Dos resultados obtidos e com base na análise estatística aplicada, pôde-se concluir que: o ácido fosfórico a 37 por cento apresentou melhor comportamento, com valores de resistência ao cisalhamneto significativamente maiores que o oxalato de potássio a 3 por cento; o tempo de aplicaçäo de 60 segundos do ácido fosfórico a 37 por cento, dentre todos os grupos, foi o que melhor resultado apresentou; dentre as formulaçöes, as que melhor se comportaram foram o ácido fosfórico a 37 por cento em gel, e o oxalato de potássio a 3 por cento, em soluçäo; a contaminaçäo salivar dos espécimes interferiu no poder de uniäo da resina composta ao esmalte, embora näo determinando significância estatística; o teste de Tukey-Kramer demonstrou que os valores médios, em MPa, foram menores quando se usou o oxalato de potássio a 3 por cento

Efeito do tempo de condicionamento ácido do esmalte na retençäo das resinas compostas / Effect of enamel condictional acid time in composite resins retention

Foi verificado o efeito do condicionamento ácido do esmalte com ácido fosfórico a 37 por cento por 15, 30 e 60 segundos, na adesäo das resinas Adaptic II, Prisma Fil e Herculite, através de testes de cisalhamento. Os resultados obtidos mostraram que o tempo de condicionamento ácido ideal variou para as diferentes resinas testadas, sendo que para a resina Herculite o melhor tempo de condicionamento foi 30 segundos e para a resina Adaptic II, 60 segundos. A resina Prisma Fil apresentou valores de adesäo estatisticamente semelhantes para todos os tempos testados

[Intravenous drop of calcium gluconate for phosphorus burns].

20 patients with phosphor burn (TBSA 2%-75%) were cured by i.v. drop of calcium gluconate combined with other therapies including eschar conservation. Our experimental data showed that dogs with burn by spreading 85% phosphoric acid and napalm locally increased the level of plasma phosphorus and pathological damages to the heart, lung, kidney and etc were similar to those previously reported phosphorus burns. Intravenous drop of calcium gluconate after phosphate burn reduced the level of plasma phosphorus to normal rapidly and lessened the visceral damages. We consider that i.v. drop of calcium gluconate can accelerate the elimination of phosphorus, and prevent phosphorus poisoning after phosphorus burns.

Chlorine gas toxicity from mixture of bleach with other cleaning products--California.

From October 1987 through November 1989, five episodes of chlorine gas exposure with toxicity to at least 14 persons occurred at two state hospitals in California. Each hospital provides inpatient treatment to approximately 1000 forensic psychiatric patients. As part of their rehabilitation programs, selected patients perform cleaning duties under the supervision of janitors or nursing staff. Each incident occurred during the performance of these duties and involved the mixture of bleach (sodium hypochlorite) and a phosphoric acid cleaner by inpatients. This mixture produced chlorine gas and other chemical byproducts (Figure 1a and 1b) and resulted in temporary illness in exposed persons.

Surgical implications of acid ingestion.

Ingestion of mineral acid may be accidental or intentional. This form of corrosive usually sears the esophageal mucosa only to produce major injury to the stomach. The prepyloric antrum is almost always injured, but the fundus and cardia may be involved if the stomach is empty at the time of ingestion. Clinically, significant esophageal injury occurs in less than 20 per cent. Initial treatment is supportive, with early operation reserved for patients with severe ingestion in whom gastric necrosis rapidly ensues. In the more typical patient, however, late gastric outlet obstruction still makes surgical therapy mandatory. Subtotal gastrectomy with Billroth I reconstruction is usually possible and is the treatment of choice. Total parenteral nutrition is a useful adjunct.