Creating protective appliances for preventing dental injury during endotracheal intubation using intraoral scanning and 3D printing: a technical note

Digital dentistry has influenced many dental procedures, such as three-dimensional (3D) diagnosis and treatment planning, surgical splints, and prosthetic treatments. Patient-specific protective appliances (PSPAs) prevent dental injury during endotracheal intubation. However, the required laboratory work takes time, and there is the possibility of tooth extraction while obtaining the dental impression. In this technical report, we utilized new digital technology for creating PSPAs, using direct intraoral scanners and 3D printers for dental cast fabrication.

Effect of zirconia surface treatment using nitric acid-hydrofluoric acid on the shear bond strengths of resin cements

PURPOSE: The aim of this study was to compare the surface roughness of zirconia when using Zircos E etching system (ZSAT), applying a nitric acid-hydrofluoric acid compound as a pretreatment agent, and also to compare the shear bonding strength according to different resin cements. MATERIALS AND METHODS: ZSAT, air abrasion, and tribochemical silicacoating were applied on prepared 120 zirconia specimens (10 mm in diameter, 7 mm in height) using CAD/CAM. Each 12 specimens with 4 different resin cements (Panavia F 2.0, Rely X Unicem, Superbond C&B, and Hot bond) were applied to test interfacial bond strength. The statistical analysis was performed using SAS 9.1 (SAS Institute Inc., Cary, NC, USA). The results are as follows: after application of the ZSAT on the zirconia specimens, surface roughness value after 2-hour etching was higher than those after 1- and 3-hour etching on SEM images. RESULTS: For Superbond C&B and Rely X Unicem, the specimens treated with ZSAT showed higher shear bond strength values than those treated with air abrasion and tribochemical silicacoating system. Regarding the failure mode of interface over cement and zirconia surface, Rely X Unicem and Hot bond showed cohesive failures and Panavia F 2.0 and Superbond C&B showed mixed failures. CONCLUSION: Zircos E etching system in zirconia restoration could increase its shear bond strength. However, its long term success rate and clinical application should be further evaluated.

Computer-controlled local anesthetic delivery for painless anesthesia: a literature review

Local anesthesia is administered to reduce pain during dental treatments, but may itself cause pain and contribute to increased dental fear. Computer-controlled local anesthetic delivery (CCLAD) is one the method to reduce patient pain during local anesthesia; it is a device that slowly administers anesthetics by using a computerized device to control the injection speed. This literature review aims to provide an objective assessment of the usefulness of CCLAD for controlling pain by reviewing papers published to date that have used CCLAD.

Computer-controlled local anesthetic delivery for painless anesthesia: a literature review

Local anesthesia is administered to reduce pain during dental treatments, but may itself cause pain and contribute to increased dental fear. Computer-controlled local anesthetic delivery (CCLAD) is one the method to reduce patient pain during local anesthesia; it is a device that slowly administers anesthetics by using a computerized device to control the injection speed. This literature review aims to provide an objective assessment of the usefulness of CCLAD for controlling pain by reviewing papers published to date that have used CCLAD.

Management of hyperthyroid patients in dental emergencies: a case report

The prevalence of thyroid disease, particularly hyperthyroidism, has rapidly increased in Korea in the past 10 years. Therefore, it is important to consider the complete medical history including thyroid disease in patients under dental treatment. Both the drugs used for dental treatment and psychological symptoms associated with treatment can induce emergencies in hyperthyroid patients. This case report considers emergency situations during dental treatment for hyperthyroid patients, and discusses risk factors and related concerns.

Management of hyperthyroid patients in dental emergencies: a case report

The prevalence of thyroid disease, particularly hyperthyroidism, has rapidly increased in Korea in the past 10 years. Therefore, it is important to consider the complete medical history including thyroid disease in patients under dental treatment. Both the drugs used for dental treatment and psychological symptoms associated with treatment can induce emergencies in hyperthyroid patients. This case report considers emergency situations during dental treatment for hyperthyroid patients, and discusses risk factors and related concerns.

Comparison of the retention of the full veneer casted gold crowns with varying convergence angle, crown length and dental cements / 대한치과보철학회지

PURPOSE: The aim of this research was to establish the effect and variation in differing convergence angle and length of abutment on the retention of full veneer casted gold crown. MATERIALS AND METHODS: Two different length,5 mm and 10 mm in height with convergence angles of 5, 10, 15 and 25 degrees crowns were fabricated. Cementation was done using cements; zinc phosphate cement (Fleck's zinc phosphate cement), resin-modified glass ionomer cement (Vitremer) and resin cement (Panavia 21). These were tested for tensile force at the point of separation by using Instron Universal Testing Machine. Statistical analysis was done by SAS 6.04 package. RESULTS: In all cements the mean retention decreased with significant difference on increase of convergence angle (P<.05). Increase in every 5 degree-convergence angel the retention rate decreased with resin-modified glass ionomer cement of 15.9% and resin cement of 14.8%. With zinc phosphate cement, there was largest decreasing rate of mean retention of 25.5% between convergence angles from 5 degree to 10 degree. When the crown length increased from 5 mm to 10 mm, the retention increased with the significant difference in the same convergence angle and in all types of cement used (P<.05). CONCLUSION: The retention was strongly dependent on geometric factors of abutment. Much care is required in choosing cements for an optimal retention in abutments with different convergence angles and crown lengths.

A Case of Tyrosinemia Type 1 with Cytomegalovirus Infection / 소아과

Tyrosinemia type 1 is an autosomal recessive inborn error of tyrosine metabolism that caused a mutation in the gene coding for the enzyme fumarylacetoacetate hydrolase(FAH). As a result, maleylacetoacetate(MAA) and fumarylacetoacetate(FAA) are formed. The accumulated FAA is converted into succinylacetone(SA) and succinylacetoacetate(SAA) which are excreted in urine. The first report with typical clinical and biochemical findings was presented by Sakai in 1957. Clinically, the disorder is characterized by progressive liver damage with liver failure, a high risk of hepatocellular carcinoma and renal tubular dysfunction hypophosphataemic rickets. Some patients have porphyria-like episodes. Liver transplantation has been the ultimate treatment of tyrosinemia. However pharmacological therapy with 2-(2-nitro-4-trifluoromethylbenzoyl) -1,3-cyclohexanedione(NTBC) has offered a new therapeutic option in addition to dietary restriction of tyrosine and phenylalanine. We experienced a case of tyrosinemia type 1 with cytomegalovirus infection in a 4-month-old male who improved by dietary restriction of tyrosine and phenylalanine.

Two Cases of Transient Neonatal Diabetes Mellitus in Twin Brothers / 대한소아내분비학회지

Neonatal diabetes mellitus (NDM) is defined as hyperglycemia that presents clinical symptoms within the first month of life and requires insulin therapy to maintain euglycemia. The diabetic condition may be transient, permanent, or transient with recurrence later in life. NDM is a rare clinical disorder. Three cases of NDM have been reported in Korea so far. We experienced two cases of NDM in twin brothers who were born with small for gestational ages. Their HLA typings were DR9 and DR14, and insulin autoantibody, islet cell antibody, GAD-reactive autoantibody, and insulin receptor antibody were not found. The genetic analysis with polymorphic DNA markers for chromosome 6 indicated paternal uniparental isodisomy.

Clinical Study of Benign Convulsion with Acute Gastroenteritis / 소아과

PURPOSE: This study was performed to characterize clinical features of benign convulsions with acute gastroenteritis(CwG) in infants. METHODS: We reviewed 83 consecutive seizures in 42 patients with CwG between January 1995 and December 2003. CwG was defined as convulsions having the following two characteristics : (a) seizures accompanied with symptoms of gastroenteritis without clinical signs of dehydration or electrolyte derangement; and (b) the body temperature remained less than 37.5 before and after the seizures. The clinical characteristics were compared between rotavirus positive and negative groups. RESULTS: Their ages ranged from 6 to 37 months(mean, 18.1 months). The average interval between the onset of astroenteritis and that of seizures was 56.4 hours. The seizure episodes ranged from one to seven times in cluster. Two or more seizures occurred in 23 patients(54.8%) within one episode of gastroenteritis. The seizure types constituted of generalized tonic-clonic(89.2%), generalized tonic(9.6%), or generalized clonic(1.2%). Only four of 42 patients showed abnormal electroencephalogram(EEG) findings, which reverted to normal during the follow-up period. All patients displayed normal psychomotor development without recurrent seizures, except two patients who had febrile seizures and a recurrence of CwG. Comparing the rotavirus positive group with the rotavirus negative group, the rotavirus positive group had more females, older patients and longer durations of seizure, significantly(P<0.05). CONCLUSION: The prognosis of afebrile seizures following acute gastroenteritis was benign.

Changes in High Levels of 17 alpha-Hydroxyprogesterone at Neonatal Screening / 대한소아내분비학회지

PURPOSE:There are some cases of false positive in neonatal screening for congenital adrenal hyperplasia. To understand its significance of the increased 17 alpha-hydroxyprogesterone(17 alpha-OHP) levels in the cases of positive result, we followed its levels during infancy. METHODS:From July 1997 to June 1998, totally 1,730 babies were screened for congenital adrenal hyperplasia(CAH) measuring 17 alpha-hydroxyprogesterone(17 alpha- OHP) using an enzyme immunoassay(EIA) on dried blood spots. In infants of positive result, the radioimmunoassay(RIA) was used measuring 17 alpha-OHP in serum. And we followed up the levels of 17 alpha-OHP during infancy. Cortisol and ACTH were also measured and followed up in the morning simultaneously. RESULTS:No CAH was detected during the study period. With the 13 ng/mL cutoff limit for 17 alpha-OHP before March 1998, the recall rate was 3.09%. With the 20 ng/mL cutoff limit after March 1998, the recall rate was decreased to 1.58%. Follow-up of the high levels of 17 alpha-OHP in positive cases showed a sharply decreased curve according to age. CONCLUSION: In clinically normal neonates, the high levels of 17 alpha-OHP at screening decreased continuously during infancy.

Changes in High Levels of 17 alpha-Hydroxyprogesterone at Neonatal Screening / 대한소아내분비학회지

PURPOSE:There are some cases of false positive in neonatal screening for congenital adrenal hyperplasia. To understand its significance of the increased 17 alpha-hydroxyprogesterone(17 alpha-OHP) levels in the cases of positive result, we followed its levels during infancy. METHODS:From July 1997 to June 1998, totally 1,730 babies were screened for congenital adrenal hyperplasia(CAH) measuring 17 alpha-hydroxyprogesterone(17 alpha- OHP) using an enzyme immunoassay(EIA) on dried blood spots. In infants of positive result, the radioimmunoassay(RIA) was used measuring 17 alpha-OHP in serum. And we followed up the levels of 17 alpha-OHP during infancy. Cortisol and ACTH were also measured and followed up in the morning simultaneously. RESULTS:No CAH was detected during the study period. With the 13 ng/mL cutoff limit for 17 alpha-OHP before March 1998, the recall rate was 3.09%. With the 20 ng/mL cutoff limit after March 1998, the recall rate was decreased to 1.58%. Follow-up of the high levels of 17 alpha-OHP in positive cases showed a sharply decreased curve according to age. CONCLUSION: In clinically normal neonates, the high levels of 17 alpha-OHP at screening decreased continuously during infancy.

Assessment of Genotoxic Hazard in Petrochemical Workers / 대한산업의학회지

In order to evaluate the genotoxic hazard among workers potentially exposed to low level petrochemical substances, the analyses of micronuclei (MN) and sister chromatid exchanges (SCEs) in lymphocytes were performed in 46 male workers (as exposed group) and 46 nonexposed subjects (as control group). Mean frequencies of MN and SCEs (respectively, 12.9/1000 cells and 6.5/cell) in exposed group were very significantly higher than those (10.2/1000 cells and 5.4/cell) in control group. And there were also significant differences in mean frequencies of MN and SCEs adjusted for age, employment duration, smoking, and drinking between two groups. Median frequencies of MN and SCEs in exposed group were very significantly higher than those in control group. Frequencies of SCEs were higher in smokers than in non-smoker. Frequencies of MN in smokers, however, were similiar to those of non-smoker. Interaction between exposure and smoking on MN and SCEs induction was not observed. The results suggest that there is genotoxic hazard in high risk group like workers handling carcinogens in petrochemical plants and the analyses of MN and SCEs are useful biomarkers for the exposure to hazard substances even at the level below the exposure limit.