• Journal of Korean society of Dental Hygiene
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• v.13 no.4
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• pp.701-711
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• 2013

Objectives : The aim of this study was to evaluate the pH and buffering capacity in some commercial fermented milks in Korea. Methods : The study was carried ouf from June to August, 2012. In 35 liquid type, 79 condense-stirred type and 71 condense-drink type fermented milks, available on the market, pH and buffering capacity were measured. Titration(with NaOH) was used to determine the buffering effect of each fermented milk. They were titrated with 1 M sodium hydroxide, added in 0.1 milliliters increments, until the pH reached about 5.5 and 7.0. Results : The average pH of tested fermented milks was $4.08{\pm}0.27$. The average pH values of fermented milks were $3.64{\pm}0.22$ in liquid type, $4.14{\pm}0.12$ in condense-stirred type, and $4.22{\pm}0.17$ condense-drink type. The average buffering capacity (pH 5.5) of tested fermented milk was $2.40{\pm}0.54$. The average buffering capacity (pH 5.5) of liquid type fermented milk was $2.37{\pm}0.33$, condense-stirred type fermented milk was $2.77{\pm}0.46$ and condense-drink type fermented milk was $2.01{\pm}0.42$. The average buffering capacity (pH 7.0) of tested fermented milks was $4.00{\pm}0.87$. The average buffering capacity (pH 7.0) of liquid type fermented milk was $3.11{\pm}0.36$, condense-stirred type fermented milk was $4.78{\pm}0.55$ and condense-drink type fermented milk was $3.58{\pm}0.59$. Conclusions : The average pH of tested fermented milks in this study was lower than pH 4.5. The type of fermented milks was an important factor for selection of fermented milk which is related with enamel erosion.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.1
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• pp.1-10
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• 2008

The purpose of this study was to develop the wireless pH telemetry lasting longer than 24 hours in the mouth to overcome the limits of conventional wire telemetry previously used for salivary and plaque pH measurement, and to assess its effectiveness. We developed a wireless pH telemeter which can measure and store the pH profile data during more than 24 hours. It was composed of intraoral part; pH sensor of antimony electrode, battery and microprocessor for data storage, and extraoral part; control/data receiver and data analyzing software which was newly made for this device. After inspecting wireless electrode for accurate measurement, it was attached to the removable intraoral appliance and delivered to the volunteer who was told to wear except brushing time, retrieved after 24 hours and finally the pH profile data was extracted and analyzed. When compared with conventional wire telemetry, this device showed similar results and induced less discomfort to examinees. The data showed pH changes at same time when examinees ate various scheduled foods and beverages. With this method it became possible to accurately measure pH changes within mouth for long time in accordance with individual's lifestyle, definitely reducing the discomfort inflicted to the examinees' life.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.4
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• pp.624-629
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• 2004

The purpose of study was to observe the effect of fluoride and calcium on enamel remineralizaton in vitro. Human premolar enamel specimens were prepared by demineralization in $0.1{\sim}l.0%$ citric acid for 60 minutes. They were remineralized for 6 hours in one of the 1311owing solutions : (1) artificial saliva, (2) artificial saliva with 100ppmF, (3) artificial saliva with 1000ppmF, (4) artificial saliva with 1000ppmCa, and (5) artificial saliva with 100ppmF and 1000ppmCa. No significant remineralization was occurred in artificial saliva and artificial saliva with 100ppmF. Significant remineralization was observed in artificial saliva with 1000ppmF at 3 hours, and in artificial saliva with 1000ppmCa and artificial saliva with 100ppmF and 1000ppmCa at 3 and 6 hours(P<0.05). The remineralization effect of artificial saliva with 100ppmF and 1000ppmCa was greater than that of artificial saliva or artificial saliva with 100ppmF. Addition of F to 100ppm or 1000ppm, addition of Ca to 1000ppm, and increasing the concentration of F from 100ppm to 1000ppm did not significantly increase the remineralization.

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.2
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• pp.262-268
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• 2006

The purpose of this in vitro study was to evaluate the remineralizing effects of Nd : YAG laser irradiation and fluorides application on primary tooth enamel eroded by acidic drink. The materials were 30 sound primary teeth with intact smooth enamel surfaces. They were demineralized with Coca-cola at $37^{\circ}C$ for 12 hours and then irradiated by Nd: YAG laser with 6W power, $50mJ/cm^2$ energy density. and 20Hz pulse repetition. After laser irradiation, teeth were treated by three kinds of fluorides : (1) 0.05% NaF solution, (2) 1.23% APF gel and (3) 0.1% fluoride varnish. Diagnodent scores and microhardness (VHN) were measured before and after the each treatment. The results were as follows: 1. Diagnodent scores decreased to 23.51% from the initial after demineralization, and then increased to 37.37% after laser irradiation, and to 51.34% after fluoride treatment. There were significant differences between the total scores of initial, demineralization, laser irradiation and fluoride treatment (P<0.05). There was no significant difference between scores after fluoride treatment according to fluoride types. 2. Microhardness(VHN) decreased to 33.58% from the initial after demineralization and then increased to 43.99% after laser irradiation, and to 51.38% after fluoride treatment. There were significant differences between the total scores of initial, demineralization, laser irradiation and fluoride treatment (P<0.05). There was no significant difference between scores after fluoride treatment according to fluoride types.

• The Korean Journal of Nuclear Medicine
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• v.31 no.3
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• pp.388-394
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• 1997

Temporomandibular (TM) joint Pain results from many etiologic factors. The aim of this study was to evaluate the utility of Bone SPECT in patients with TM joint pain. The subjects were 34 patients with TM joint pain. All patients underwent plain radiography, planar bone scan, and Bone SPECT The intensity of radioisotope uptake at TM joint was graded into three; no increased uptake above the background activity as grade 0, uptake similar to occipital bone as grade I, and uptake similar to maxillary sinus as grade II. Clinical findings and therapeutic methods were reviewed. Twenty-seven patients (80%) out of 34 patients with TM joint pain had increased uptake in bone SPECT. Twenty-one (78%) out of 27 patients had increased uptake in the mandibular condyle and remaining six patients (22%) had uptake in the mandibular and maxillary arch, which proved to be dental problem. Seven patients (21%) out of 34 were grade as 0, four (12%) were grade I, 23 (68%) were grade II. Four patients with grade I had clicking sound and symptoms which were subsided with medication in all cases. Among 23 patients with grade II, 7 patients had clicking sound and 14 patients underwent medication and decompression therapy. With Planar bone scan, 11 cases (32%) had increased uptake in TM joint area. Plain radiography revealed narrowing, distension, erosion and limitation of TM joint in 16 cases (47%). Bone SPECT can be valuable for screening and managing the patients with TM joint pain. Patients with grade II needed intensive treatment such as joint aspiration. However degree of the radioisotope uptake did not well correlated with clinical symptoms.