Journal of Dental Sciences

Effects of storage solutions on mineral contents of dentin

Asli Secilmis, Erhan Dilber, Fatma Gokmen, Nilgun Ozturk, Tuba Telatar — 2011-10-20

Abstract: Background/purpose: It is important to understand how storage conditions affect the tooth structure for in vitro studies. There is little information regarding the selection of an appropriate storage solution. This study was conducted to determine the influence of storage solutions on the mineral contents of dentin.Materials and methods: Ninety dentin specimens were obtained from 30 molar teeth. Specimens were divided into two groups of 45 each (storage for 45 and 90 days). Each of the two groups was further divided into nine storage solution groups (n=5). For the control group, freezing was used to store the teeth. The mean percentage weights of calcium, potassium, sodium, and phosphorus in each dentin slab were measured by inductively coupled plasma-atomic emission spectrometry. Two-way analysis of variance and Tukey’s honest significant difference test were used to analyze the data (P=0.05).Results: There were significant differences in calcium among groups. The potassium level of slabs stored in artificial saliva and the sodium level of slabs stored in buffered solutions and saline solution increased (P<0.05). Potassium, sodium, and phosphorus levels were highest when stored for 45 days (P<0.05).Conclusion: The storage solution and storage time affected the compositional structure of dentin. The results suggest that storage processes may influence outcomes of in vitro dental research.

Effects of orthodontic treatment with a fixed appliance on the caries experience of patients with high and low risk of caries

Muhammet Karadas, Kenan Cantekin, Mevlut Celikoglu — 2011-10-20

Abstract: Background/purpose: We tested the hypothesis that there are no differences between changes in the caries experience in a group of orthodontic patients at high and low risk for caries.Materials and methods: Data were obtained from clinical and radiographic examinations of 186 orthodontic patients being treated with a fixed appliance in both arches. Patients were divided into two groups based on their prebonding decayed, missing, and filled permanent teeth (DMFT) scores and caries risk susceptibility. Statistical analyses were performed using the Wilcoxon and Mann–Whitney U tests.Results: Changes in DMFT values were 0.39 ± 0.66 and 1.46 ± 1.24 for the low- and high-caries risk groups, respectively. Changes in each group were significant (P 0.05).Conclusion: The hypothesis was rejected; the difference in DMFT scores between the caries risk groups was statistically significant. Although patients in both groups cared for their teeth during treatment, oral hygiene after treatment was worse than that before treatment. These results suggest that conventional oral hygiene procedures, especially for patients in the high-caries risk group, are less useful in preventing carious lesions during orthodontic treatment, and thus such patients must follow a very rigid oral hygiene protocol during orthodontic treatment with a fixed appliance.

Pullout strengths of orthodontic palatal mini-implants tested in vitro

2011-10-31

Abstract: Background/purpose: New modified mini-implants are used in orthodontic practice to reinforce palatal anchorage. The aim of this study was to evaluate the anchorage strengths of palatal mini-implants in terms of their vertical and horizontal pullout strengths.Materials and methods: Thirty palatal mini-implants (2mm in diameter) of three brands (Absoanchor, Bio-Ray, and Lomas) were manually driven into artificial bone (Sawbones) to a depth of 5mm. Their vertical and horizontal pullout strengths were measured using a material testing machine. The Kruskal–Wallis test was used to assess differences among brands (P<0.05).Results: The pullout strengths of all the brands were significantly greater than routine orthodontic forces. The vertical pullout strength of the Absoanchor mini-implants was the lowest among the tested brands, and the horizontal pullout strengths of the Lomas and Absoanchor mini-implants were significantly higher than that of the Bio-Ray mini-implant. There was no significant relationship between the insertion torque and pullout strength in the vertical or horizontal directions.Conclusion: The pullout strengths of mini-implants were significantly greater than normal orthodontic forces. Moreover, no significant correlation was found between the insertion torque and pullout strength.

Lysyl oxidase-like 3 mRNA expression indicates poor survival from oral squamous cell carcinoma

2011-10-20

Abstract: Background/purpose: Oral squamous cell carcinoma (OSCC) is highly prevalent worldwide. Lysyl oxidase (LOX) is an important enzyme that modulates the extracellular matrix. The LOX superfamily contains LOX and LOX-like (LOXL) enzymes. The aim of the present study was to determine the expressions of LOXL genes in OSCC.Materials and methods: RT-PCR was performed to detect messenger (m)RNA expression of the LOXL genes, LOX-L1, -L3, and -L4, in paired OSCC and non-cancerous matched tissues (NCMTs).Results: Increased mRNA expressions of LOX-L1 and LOX-L3 in OSCC relative to NCMTs were identified in 41% and 65% of OSCC samples, respectively. The normalized mRNA expression of LOXL-3 was 1.11 ± 0.15 in OSCC, which was significantly higher than 0.68 ± 0.12 in NCMTs (P = 0.004). The increased expression of LOX-L3 was associated with worse survival of OSCC patients (P = 0.028).Conclusion: The results indicated the frequent increase in LOX-L3 mRNA expression in OSCC, and the value of LOX-L3 mRNA expression might have clinical uses in monitoring OSCC.

Effects of different ceramic and dentin thicknesses on the temperature rise during photocuring

Wen-Chieh Kuo, Yen-Hsiang Chang, Chun-Li Lin, Jau-Shing Kuo — 2011-10-24

Abstract: Background/purpose: The aims of this investigation were to describe the effect of different ceramic and remaining dentin thicknesses on substrate temperature during photocuring, and investigate whether the temperature increased by >5.5°C for different dentin/ceramic combinations.Materials and methods: Three groups of dentin thicknesses of 1.0 (D1.0), 1.5 (D1.5), and 2.0 mm (D2.0), and three groups of ceramic thicknesses of 1.5 (C1.5), 2.5 (C2.5), and 3.5 mm (C3.5) were examined. Temperature changes and the maximum temperature were observed under a high-intensity halogen light (QTH-Atralis 10 ECS program at 1200mW/cm2 for 30 seconds, Ivoclar Vivadent AG, Schaan, Liechtenstein). Four groups, D1.0–C1.5 (+11°C), D1.5–C1.5 (+7.2°C), D1.0–C2.5 (+6.7°C), and D2–0C1.5 (+5.8°C), demonstrated temperature changes of >5.5°C.Results and Conclusions: A statistical analysis showed that separate individual thicknesses and combinations of dentin and ceramic had significant effects on temperature changes (P<0.01). It was observed that the ceramic exhibited a smaller temperature shielding effect than dentin. Clinically, it would be optimal to preserve the dentin to avoid damaging pulp tissues. Where there is insufficient overall thickness (≤3.5mm), continuous high-energy output photocuring should be avoided to protect pulp tissues from thermal injury.

Effects of different denture cleaning methods to remove Candida albicans from acrylic resin denture based material

Huey-Er Lee, Chiung-Yu Li, Hsueh-Wei Chang, Yi-Hsin Yang, Ju-Hui Wu — 2011-10-24

Abstract: Background/purpose: Different denture cleaning methods have different effects. The purpose of this study was to evaluate the efficiency of six different denture cleaning methods to remove Candida albicans that had accumulated on denture-based materials.Materials and methods: We generated 140 identical acrylic resin specimens and soaked them in a suspension of C albicans. The reduction in microorganism counts after application of the different denture cleaning methods was calculated. Six cleaning methods were evaluated: a mechanical method of brushing with a toothbrush, a chemical method of soaking in a commercial cleansing tablet solution, a combined method of brushing and soaking in a commercial cleansing tablet solution, a chemical method of soaking in a commercial mouthwash solution, irradiation in an ultraviolet (UV)-light e-box, and soaking in distilled water. The effectiveness of the denture-cleaning methods in reducing C albicans was evaluated following a single cleaning event.Results: The denture cleaning techniques had considerably different efficacies in reducing C albicans. There was no significant difference among the effectiveness levels of cleaning by brushing, soaking in a commercial cleansing tablet solution, or a combination of both in removing C albicans. Similarly, the effectiveness levels of soaking in a commercial mouthwash solution or irradiation in a UV-light e-box were statistically similar.Conclusion: Compared to other methods, brushing, soaking in a commercial cleansing tablet solution, or a combination of both methods can significantly reduce the adherence of C albicans to denture samples. Compared to soaking in distilled water, soaking in a commercial mouthwash solution or irradiation with UV-light had more significant cleaning effects, but these methods were not as effective as the aforementioned three methods.

Analysis of verbal diadochokinesis in normal speech using the diadochokinetic rate analysis program

Cheng-Chieh Yang, Yuh-Mei Chung, Lin-Yang Chi, Hsiu-Hsien Chen, Yu-Tsai Wang — 2011-10-24

Abstract: Background/purpose: The purposes of this study were to report the suitability, alternate-forms reliability, and the concurrent validity of the analysis of diadochokinesis (DDK) samples in normal speech using the Diadochokinetic Rate Analysis (DRA) program.Methods: Fifteen healthy participants were recorded as they repeated various syllables as quickly and steadily as possible. When the lowest peak intensity during consonant-vowel syllables is lower than the highest peak intensity during intersyllable pauses, the DRA output is incorrect and the DDK sample is defined as nonexecutable. The executable DDK samples were hand measured and executed by the DRA program to generate outputs at different thresholds. Analyses were based on the percentage of nonexecutable DDK samples and the comparisons of the results between repeated analyses at different thresholds and between automatic and manual measuring methods.Results: One-ninth of the DDK samples could not be accurately executed. When the protocol could be accurately executed, the reliability at different thresholds and the validity between different measuring methods were both satisfactory.Conclusion: Although inadvertent articulatory breakdown or the incoordination of intrasyllabic movements were major limiting factors to the suitability, the alternate-forms reliability and concurrent validity of the analysis of DDK in adults with normal speech using the DRA program were both satisfactory if the DDK train was executable by DRA.

Dental and periodontal health status of subjects with sickle cell disease

Esra Guzeldemir, Hilal Uslu Toygar, Can Boga, Ulkem Cilasun — 2011-10-24

Abstract: Background/purpose: Sickle cell disease (SCD) is a chronic, hereditary, autosomal recessive disorder. The pathophysiology of SCD is thought to result from polymerization of hemoglobin S in red blood cells under hypoxic conditions, which results in vaso-occlusion. The aim of this study was to determine the periodontal and dental health status of patients with SCD.Materials and methods: Fifty-five SCD patients and 41 healthy individuals were evaluated. Detailed medical and dental histories were taken, and a record made of dental status (missing teeth, restorations, impacted teeth, root canal treatment), periodontal status [plaque index (PI), gingival index (GI), probing depth (PD), bleeding on probing (BOP)], alveolar bone level (ABL), mandibular cortex index, and bone quality index.Results: Two hundred and six teeth were missing, and a total of 195 teeth had restorations. Between-group differences existed for the PI, GI, and BOP; these variables were higher in patients than in the healthy individuals (P<0.0001). No between-group differences existed for PD. In patients, there was a positive correlation between PD and BOP (P<0.0001; r=0.657), PD and GI (P=0.02; r=0.299), PD and PI (P=0.01; r=0.343); BOP and GI (P<0.0001; r=0.503), BOP and PI (P<0.0001; r=0.496); and GI and PI (P=0.003; r=0.388). The ABL in patients was found to be similar to that of the general population with an unknown periodontal condition.Conclusion: No clinical periodontal disease or attachment loss was detected in patients. However the PI, GI, and BOP were significantly higher in patients with SCD, which may reflect an as yet undefined variable response to microbes. There were no significant differences, however, in pocket depth between the two groups. Therefore we are unable to confirm any significant relationship between SCD and periodontal diseases. Oral health is not a major concern for SCD patients. The reason for this finding may be the potentially severe complications of SCD, which mean that oral and dental problems are not major concerns for this particular group of patients.

Effects of orthodontic treatment with fixed appliances on oral health status: A comprehensive study

2011-10-24

Abstract: Background/purpose: The purpose of the present study was to assess changes in the oral health status in a group of young Turkish dental patients undergoing orthodontic therapy.Materials and methods: Data were obtained from clinical and radiographic examinations of 659 patients (with a mean age of 14.2 ± 1.59 years, including 39% males and 61% females), who were being treated with a fixed appliance in both arches at the Department of Orthodontics, Faculty of Dentistry, Ataturk University, Erzurum, Turkey. Changes in the decayed, missing, and filled permanent teeth (DMFT) counts and plaque index (PI) were evaluated. Statistical analysis was carried out using Wilcoxon and Mann–Whitney U tests.Results: Total DMFT counts at the time of debonding were higher than at prebonding (P < 0.05) with no gender difference. The PI showed minimum values at the beginning of orthodontic therapy and maximum values at the end of therapy.Conclusions: The results of this study showed that DMFT counts and the PI increased in a group of young dental patients undergoing orthodontic therapy, and thus patients undergoing orthodontic therapy must follow very rigid oral hygiene protocols.

Treatment of traumatized maxillary central incisors

Jun Kuo, Yng-Tzer J. Lin — 2011-10-24

Abstract: Traumatic injury to the upper anterior teeth is not uncommon in young children. Dental ankylosis frequently occurs when teeth are traumatically luxated or replanted after being avulsed. Orthodontic movement of a traumatized tooth is difficult, especially when treating an ankylosed tooth without surgical luxation and distraction osteogenesis. This report describes a case of a patient with class I crowded malocclusion and labially displaced and intruded traumatized maxillary incisors. The protruded traumatized incisors were successfully brought to an acceptable position with acceptable gingival esthetics through the use of simple orthodontic traction combined with first-premolar extraction. An acceptable overbite and overjet were achieved within 14 months after completion of orthodontic treatment.