ABSTRACT
The aim of this study is to compare cariogenic characteristics of fluoride-sensitive Streptococcus mutans [fluoride-sensitive (FS) S. mutans ] and fluoride-resistant Streptococcus mutans [fluoride-resistant (FR) S. mutans] in the presence of sucrose, and to evaluate its effect on cariogenic biofilm formation. S. mutans ATCC 25175 was continuously cultured in trypticase soy broth (TSB) containing NaF (70 ppm) for 40 days to generate FR S. mutans . FS and FR S. mutans were inoculated in TSB with or without 2% sucrose, and optical density and pH were measured every hour. An oral biofilm was formed using saliva bacteria and analyzed through confocal laser scanning microscopy and CFU count. Finally, the expression of glucosyltransferases genes of both S. mutans was investigated through RT-PCR. FR S. mutans exhibited slower growth and lower acidogenicity in the presence of sucrose compared to FS S. mutans . Both cariogenic and single species biofilm formation was lower in the presence of FR S. mutans , along with reduced number of bacteria. FR S. mutans showed significantly low levels of gtfB, gtfC, and gtfD expression compared to FS S. mutans . On the basis of results, FR S. mutans may be less virulent in the induction of dental caries.
ABSTRACT
The purpose of this study is to evaluate the validity of primary anterior zirconia crown made with Computer Aided Design/Computer Aided Manufacturing (CAD/CAM) technology by analyzing fracture strength and translucency parameter.Zirconia crown was designed with CAD software, using 3D scanned data of #61 tooth model. Crown fabrication was performed with CAM machine using zirconia block. Zirconia crowns were divided into 3 groups according to thickness(0.3, 0.5, and 0.7 mm), and fracture strength was compared with 1.0 mm thickness of resin strip crown. The compressive force was applied with universal testing machine at 30° along the incisal edge at increments of 1 mm/min. For translucency evaluation, 0.3, 0.5, and 0.7 mm thickness of zirconia specimens were fabricated and translucency was measured with spectrophotometer.Among zirconia groups, there was a significant increase in fracture strength as thickness increased (p Thin primary anterior zirconia crown can be designed and fabricated according to individual needs by using CAD/CAM. Restoration with thin crown would reduce the amount of tooth reduction, risk of pulp exposure, and make more esthetic restoration possible.
ABSTRACT
Patient management is considered an important factor in dental field. The aim of this review is to analyze the efficacy of hypnosis to treat fear, anxiety, pain, stress of dental patients, and see how it can be adopted in dentistry for improving patient satisfaction. Medline research was carried out to find the use of hypnosis in dentistry and other aspects of hypnosis in medical area. It can help patient more comfortable, relax, and accordingly reduce patient's negative feelings such as fear, anxiety, pain, stress during dental treatment. Also, it affects patient recovery after surgery by accelerating healing speed and reinforce immune system. When hypnosis is used with other anesthetic method, it can reduce the use of main medication, leading to reduce possibility of side effect. Therefore, using Hypnosis can give patients more comfortable dental experience, both mentally and physically, ultimately making patients more satisfied with the dental treatment.