Effects of cheese extract and its fractions on enamel demineralization in vitro and in vivo in humans

In order to isolate and identify the most active anti-cariogenic components(s) of aqueous cheese extract (CE), we separated it into low (LMW) (MW less than 500), medium (MMW) (500 less than MW less than 10,000), and high (HMW) (MW greater than 10,000) molecular weight fractions by means of the Amicon ultrafiltration system. These fractions were then tested in vitro with a bacterial system containing S. mutans, adapted from that of Turtola (1977). The LMW fraction reduced the demineralization caused by the fermentation of sucrose by 96% (p less than 0.001) as compared with the water control; this was not significantly different from a 50% concentration of the CE. The MMW and HMW fractions reduced demineralization by 36 and 42%, respectively. The concentrations of acid-soluble calcium and phosphorus in CE, LMW, MMW, and HMW were 1509 and 462, 991 and 310, 231 and 7, and 162 and 3 micrograms/mL, respectively. A solution containing the same levels of calcium and phosphorus as CE was somewhat more effective in reducing demineralization in vitro than was CE itself (p less than 0.01). In vivo, the addition of these same calcium and phosphorus levels to a 10% sucrose solution reduced its cariogenicity by 67% (p less than 0.001), as judged by the intra-oral cariogenicity test (ICT). Plaque calcium and phosphorus concentrations were significantly higher in the ICT plaque samples subjected to the sucrose-Ca,P solution (p less than 0.01) than in the sucrose control. The resting pH, minimum pH, and shape of the pH curves produced by the sucrose control and sucrose-Ca,P were similar.(ABSTRACT TRUNCATED AT 250 WORDS)     

Incidence and quantification of mycoplasma in saliva in patients with periodontal disease and subjects with healthy gingiva

The ecological niche of oral mycoplasmas are both gingival pockets in patients suffering periodontitis (PP) and gingival sulci in individuals with healthy gingiva (HG). The mycoplasmas migrate from these anatomical sites to the saliva and to entire oral cavity. The purpose of this report was to examine whether differences exist in the incidence and concentration of mycoplasma as determined in the saliva of thirty (30) PP and fifty (50) individuals with HG. Saliva samples were obtained from both groups, with capillary tubes and cotton swabs, and used for mycoplasma isolation and quantification. The methods employed were those recommended by the Centers for Diseases Control (CDC Atlanta, Georgia). The results showed an 80% mycoplasma incidence in group PP and 50% HG, with the following concentrations: 5.0 x 10(3) to 8.0 x 10(6) Colony Forming Units/ml (CFU/ml) in PP, and 3.0 x 10(3) to 4.5 x 10(4) UFC/ml in the HG (P less than 0.001). We conclude the both mycoplasma incidence and concentration were higher in PP than in HG individuals.     

Malocclusions and traumatic injuries in disabled schoolchildren and adolescents in Kuwait

The present study was carried out to determine the prevalence of malocclusion and traumatic injuries in disabled children and adolescents attending the special-needs schools in Kuwait. Included in the study were 818 children (438 males and 380 females), in the age groups of 3–20 years, who have visual impairment, hearing impairment, physical handicaps, or developmental disorders. The mean age of participants was 11.9 years. The survey was carried out according to the methods of WHO. The prevalence of severe malocclusion was 23.6%, and that of slight malocclusion was 37.0%. Children with Down syndrome (OR = 2.3; 95% CI = 1.51-3.52), those of increasing age (OR = 1.1; 95% CI = 1.01-1.10), and males (OR = 1.5; 95% CI = 1.05-2.07) had higher risk for the occurrence of severe malocclusion. Less than one-fifth of the subjects (16.9%) had traumatized anterior teeth. Severe malocclusion (OR = 1.8; 95% CI = 1.17-2.77) and increasing age (OR = 1.2; 95% CI = 1.13-1.26) were significant risk factors for the occurrence of traumatic injuries. We concluded that malocclusion and traumatic injuries are more prevalent among these subjects with disabilities than among the healthy population in Kuwait.     

Delay in diagnosis and its effect on outcome in head and neck cancer

We examined the records of two cohorts of patients who were seen from 1960 to 1999 with a diagnosis of squamous cell carcinoma (SCC) of the mouth and throat, one series being retrospective (n=400) and the other prospective (n=213) to find out about delays in diagnosis. The median delay in both cohorts was 3 months and the patients were responsible for the delay in most cases (n=319, 81% and n=160, 78%, respectively). Half the patients in each cohort had delayed diagnoses (n=217, 54% and n=119, 56%, respectively) and similar percentages (n=110, 53% and n=172, 47%) presented with advanced disease (stage III or IV). These were not the same patients for there was no correlation between delay and stage or survival. Logistic regression analysis showed that non-white race (p=0.01) and high-grade histology (p=0.002) predicted advanced disease. The proportion of patients presenting with advanced disease had not changed in 40 years despite public education. We suggest that some tumours may be silent and that initial symptoms do not reliably predict early disease.     

EBV-1 and HCMV in aggressive periodontitis in Brazilian patients

The purpose of the present investigation was to compare the presence of Epstein-Barr virus type 1 (EBV-1) and of Human Cytomegalovirus (HCMV) in crevicular fluid samples from deep and shallow periodontal pocket sites of Brazilian patients with aggressive periodontitis. A total of 30 systemically healthy patients with aggressive periodontitis participated in the study. Paper points were inserted into 2 gingivitis sites (<3 mm) and into 2 periodontitis sites (>5 mm) in each patient. PCR assay was used to identify genomic copies of HCMV and EBV-1. Twenty-three patients (77%) were positive for EBV-1, while only 2 patients (6%) were positive for HCMV. The McNemar test revealed a positive association between EBV-1 and periodontal lesions (p=0.043). Thirty-four (57%) out of 60 periodontitis sites were positive for EBV-1, whereas 18 (30%) gingivitis sites were positive (p=0.01). Only two sites (6.7%) were positive for HCMV. No positive association was found between HCMV and periodontitis or gingivitis (p=0.479). The elevated occurrence of EBV-1 DNA in periodontal pockets of patients with aggressive periodontitis supports a possible periodontopathic role of this virus.     

Tooth movement and cytokines in gingival crevicular fluid and whole blood in growing and adult subjects.

INTRODUCTION: Tooth movement has been studied largely with respect to the force required for tipping when pressure distribution varies along the length of the periodontal ligament. But important factors for effective canine translation include the nature and magnitude of applied stress and the patient's cell biology. The purpose of this research was to test 3 hypotheses: (1) the velocity of tooth translation (v(t)) is related to applied stress and growth status, (2) a threshold of stress accounts for the lag phase, and (3) v(t) is correlated with the ratio (AI) of 2 cytokines (IL-1beta, IL-1RA) measured in gingival crevicular fluid (GCF) and stimulated whole blood (SWB). METHODS: Continuous maxillary canine retraction stresses of 13 kPa and 4, 26, or 52 kPa were applied bilaterally in 6 growing and 4 adult subjects for 84 days. Dental models and GCF samples were collected at 1- to 14-day intervals. Cytokines were measured in GCF and SWB cell cultures. RESULTS: V(t) was positively related to stress and was higher in growing subjects (P = .001). It was also related to AI(GCF) in growers (R2= 0.56) and nongrowers (R2= 0.72). Canines moved with 52 kPa showed a lag phase, and postlag phase AI(GCF) was twice that of lag phase AI(GCF). Mean v(t) and associated AI(GCF) during the postlag phase were nearly double the values for canines moved with 13 and 26 kPa. SWB production of cytokines was dose-dependent. For growing subjects, SWB IL-1RA was correlated with v(t) (R = 0.70-0.72), and AI(SWB) and IL-1beta concentrations were correlated with AI(GCF) (R = 0.73-0.78). CONCLUSIONS: V(t) varied with growth status and stresses < or = 52 kPa; stresses of < 52 kPa showed no lag phase; and equivalent stresses yielded subject-dependent differences in v(t), which correlated with cytokines in GCF and SWB.     

唾液乳铁蛋白和溶菌酶含量与乳牙患龋的关系

目的 分析高龋和无龋儿童唾液乳铁蛋白和溶菌酶的含量,初步探讨唾液乳铁蛋白和溶菌酶含量与乳牙患龋的关系,为乳牙龋病防治提供依据.方法以高龋(龋、失、补牙数≥5,高龋组)和无龋(龋、失、补牙数=0,无龋组)儿童各40名为研究对象,双金鸡纳酸法测定唾液总蛋白含量,十二烷基硫酸钠-聚丙烯酰氨凝胶电泳分析唾液蛋白条带,免疫印迹法检测唾液乳铁蛋白和溶菌酶含量.结果高龋组总蛋白含量[(852.02±206.14)mg/L]低于无龋组[(1032.44±221.99)mg/L],差异有统计学意义(P<0.001),相对分子质量为77 000蛋白的百分含量[(12.50±7.73)IA/μg]显著高于无龋组[(8.71±4.28)IA/μg,P=0.009],相对分子质量为14 500蛋白的百分含量两组间差异无统计学意义(P=0.137).高龋组乳铁蛋白百分含量[(229.04±197.14)IA/μg]显著高于无龋组[(144.07±99.91)IA/μg,P=0.018],溶菌酶含量两组差异无统计学意义(P=0.091).结论唾液蛋白与乳牙患龋密切相关,乳铁蛋白可能是其中一种重要的成分.     

Ameloblastoma in children and adolescents

This study first reviewed the data of 37 patients aged 18 years and younger with ameloblastoma over a 16-year period and then reviewed the literature on this subject from 1970 to 2009. Of 37 patients with ameloblastoma, 23 were male and 14 were female, a ratio of 1.6:1. The mean age was 14.8 years. All lesions were in the mandible. Clinical typing included 28 solid type and 9 unicystic type. Ten cases were recurrent (27.0%). A series of literature review disclosed 233 well-documented cases of ameloblastoma in children and adolescents. The ages ranged from 4 to 20 years with a mean age of 14.5 years. The distribution among males and females were almost identical: 53.6% (125/233) males and 46.4% (108/233) females (1.16:1). The mandible was affected in 225 (96.6%), the maxilla in 8 (3.4%). Histologically, solid type (63.1%) predominated over unicystic type (36.9%). Of 226, 123 (54.4%) patients were treated with radical resection, 103 (45.6%) underwent conservative method. Owing to a high recurrent rate of ameloblastoma, solid type of tumors should be approached with radical surgical treatment, while conservative measure can be applied selectively to unicystic type. Long-term follow-up is important because recurrence may appear years after tumor removal.     

Caries and fluorosis in 6- and 9-year-old children residing in three communities in Iran

OBJECTIVES: The aim of this study was to investigate the caries and fluorosis prevalence among 6- and 9-year-old students in three communities in Iran with varying urbanization and fluoride in piped water. METHODS: Data were obtained from 523 dental examinations of 6- and 9-year olds in an upper middle class district in Teheran (T) (0.3 mg F/l), the city of Semnan (S) (1.3 mg F/l), and the village Dibaj (D) (0.2 mg F/l). RESULTS: Children in the naturally fluoridated town showed slightly higher dmfs/dfs (SD) values for both 6-year olds [S: 9.1 (9.2), T: 7.2 (7.4), D: 7.1 (6.1)] and 9-year olds [S: 6.0 (6.2), T: 4.4 (4.2), D: 5.0 (4.7)], whereas the mean dmft/dft values as well as the numbers of caries-free children were comparable. A lower prevalence of dental restorations was reported for both Semnan and Dibaj compared with Teheran. A higher prevalence of fluorosis [Tooth Surface Index of Dental Fluorosis (TSIF) 3-7] was observed in the naturally fluoridated town compared with the low-fluoridated communities. CONCLUSIONS: The ingestion of naturally fluoridated water (1.3 mg F/l) seemed to have a negligible effect on caries prevalence, but resulted in higher prevalence of dental fluorosis. It is emphasized that the study population was not adjusted for socioeconomic status, availability of dental care nor for exposures to other sources of fluoride. Nevertheless, it can be concluded that caries prevalence in Iran is quite low compared with that in other countries in the Middle East and that the elevated fluoride levels in the drinking water in Semnan may contribute to the development of mild to severe fluorosis.     

IL-12 and IL-18 levels in serum and gingival tissue in aggressive and chronic periodontitis

Oral Diseases (2011) 17 , 522–529 Objective: The aim of this study was to compare the levels of interleukin‐12 (IL‐12) and IL‐18 in gingival tissue and serum between patients with chronic (n = 18) or aggressive periodontitis (n = 12) and healthy subjects (HS) (n = 9). Methods: Gingival tissue biopsies and serum were obtained from all study subjects. The tissue was homogenized and cytokines IL‐12 and IL‐18 were quantified by enzyme‐linked immunosorbent assay. Results: Interleukin‐12 levels in gingival tissue were significantly higher in aggressive periodontitis patients than in HS; serum IL‐12 was significantly elevated in aggressive periodontitis relative to both chronic periodontitis (CP) and HS. IL‐18 levels in gingival tissue showed no significant differences between the groups. Patients with CP showed significantly elevated levels of serum IL‐18 compared with HS; however, the aggressive periodontitis group showed no significant differences with either the CP group or the HS. Conclusions: Our results showed higher levels of IL‐12 in gingival tissue and serum of patients with aggressive periodontitis, and IL‐18 was elevated in the serum of CP patients. The patterns of IL‐12 and IL‐18 are different in chronic and aggressive periodontitis; this finding suggests distinctive mechanisms of immunopathogenesis between these forms of periodontitis.     

The prevalence and antibiotic sensitivity of oral Viridans streptococci in healthy children and children with disabilities in Kuwait

The purpose of this study was to compare the antibiotic susceptibility profiles of Viridans streptococci (VS) isolated from the oral cavity of healthy children and children with disabilities in Kuwait. Plaque samples were collected from the tooth and tongue surfaces of 102 healthy children and 102 children who were intellectually disabled and institutionalized. The resistance to seven antibiotics (amoxicillin, cephalothin, clindamycin, erythromycin, penicillin G, tetracycline, and vancomycin) was tested.
A total of 330 (44.5%) VS were isolated from the children who were healthy and 411 (55.5%) from children with disabilities. The most common isolates were S. salivarias (27.3%) in healthy children; S. sanguis (22.6%) was predominant among children who were disabled. S. mutans was found in 12.1% of the healthy children and in 16.5% of the children who were disabled. The combined percentage of resistant strains (healthy and disabled) was found to be highest with amoxicillin (43%) and lowest with vancomycin (12%). S. sanguis, S. mitis and S. oralis were more resistant in healthy children (45%, 56%, and 55% respectively) than in children with disabilities (40%, 47% and 47% respectively). S. mutans was the least resistant species to all antibiotics in both groups of children. About 56% of ali streptococci isolated from both groups were resistant to at least one of the antibiotics tested.
The data showed that there was a diference in the level of resistance of oral VS isolated from healthy children and children with disabilities to some antibiotics commonly used in dentistry.     

Biological monitoring of sterilizers and sterilization failures in Norwegian dental offices in 1985 and 1996.

It is essential that dental office sterilizers be regularly challenged with biological indicators (BIs) in order to prove that the test spores are being killed during sterilization. The aims of the study were to biologically monitor Norwegian dental office sterilizers and to identify factors contributing to sterilization failure. In 1985, participants received a packet containing: (i) 4 BI units; (ii) a set of instructions; (iii) a questionnaire concerning operation (including biological monitoring) of the office sterilizer(s), and (iv) a return-address envelope. In 1996, offices were sent (i) a survey which included demographic questions and inquiries concerning instrument sterilization processes; (ii) 2 sets of 3 BI units with instructions for their use on 2 different days; (iii) 1 control BI unit that was not to be processed, and (iv) a return-address envelope. Both private and public offices participated. Response rate to the 1996 study was 60%, which was 9.1% of all dental offices in Norway. Testing results indicated a 6.3% overall sterilization failure rate. Three out of 163 steam autoclaves (SAs) (1.8% of total) and 14 out of 109 dry heat (DH) ovens (12.8% of total) failed. DH ovens were over 7 times more likely to fail BI testing than were SAs (chi2, P < 0.01). Demographic or hygiene procedural factors could not be correlated to sterilization performance (chi2, P > 0.05). The failure rate for SAs (n = 216) in 1985 was almost 5 times greater than in 1996 (8.8% vs 1.8%). Improvement in sterilizer performance during the decade may be related to issuance in 1986 of Norway's 1st infection control guidelines for dentistry and greater awareness of infection control practices and/or to increases over the previous 10 years in the number of postgraduate courses offered in infection control. The current Norwegian guidelines on infection control practices in public health services, including dentistry, recommend regular biological monitoring of sterilizers without specifying how often. There is a lack of information among Norwegian dentists as to how frequently dental office sterilizers should be regularly monitored by BI.     

Biological monitoring of sterilizers and sterilization failures in Norwegian dental offices in 1985 and 1996

It is essential that dental office sterilizers be regularly challenged with biological indicators (BIs) in order to prove that the test spores are being killed during sterilization. The aims of the study were to biologically monitor Norwegian dental office sterilizers and to identify factors contributing to sterilization failure. In 1985, participants received a packet containing: (i) 4 BI units; (ii) a set of instructions; (iii) a questionnaire concerning operation (including biological monitoring) of the office sterilizer(s), and (iv) a return-address envelope. In 1996, offices were sent (i) a survey which included demographic questions and inquiries concerning instrument sterilization processes; (ii) 2 sets of 3 BI units with instructions for their use on 2 different days; (iii) 1 control BI unit that was not to be processed, and (iv) a return-address envelope. Both private and public offices participated. Response rate to the 1996 study was 60%, which was 9.1% of all dental offices in Norway. Testing results indicated a 6.3% overall sterilization failure rate. Three out of 163 steam autoclaves (SAs) (1.8% of total) and 14 out of 109 dry heat (DH) ovens (12.8% of total) failed. DH ovens were over 7 times more likely to fail BI testing than were SAs (χ², P < 0.01). Demographic or hygiene procedural factors could not be correlated to sterilization performance (χ², P > 0.05). The failure rate for SAs (n = 216) in 1985 was almost 5 times greater than in 1996 (8.8% vs 1.8%). Improvement in sterilizer performance during the decade may be related to issuance in 1986 of Norway's 1st infection control guidelines for dentistry and greater awareness of infection control practices and/or to increases over the previous 10 years in the number of postgraduate courses offered in infection control. The current Norwegian guidelines on infection control practices in public health services, including dentistry, recommend regular biological monitoring of sterilizers without specifying how often. There is a lack of information among Norwegian dentists as to how frequently dental office sterilizers should be regularly monitored by BI.

     

The induction of gene mutations and micronuclei by oxiranes and siloranes in mammalian cells in vitro

Oxiranes and siloranes are candidate molecules for the development of composite materials with low shrinkage. Since some of these molecules are highly reactive, they could lead to adverse biological effects from underlying genetic mechanisms. Therefore, we analyzed the formation of micronuclei (chromosomal aberrations) and the induction of gene mutations (HPRT assay) in mammalian cells. The numbers of micronuclei induced by the oxirane di(cyclohexene-epoxidemethyl)ether (Eth-Ep) at low concentrations (10 micro M) were about five-fold higher than controls. The related compound epoxy cyclohexyl methyl-epoxy cyclo-hexane carboxylate (Est-Ep) was less effective. The activity of diglycidylether of bisphenol A (BADGE) was even lower but similar to the most reactive silorane, di-3,4-epoxy cyclohexylmethyl-dimethyl-silane (DiMe-Sil). No induction of micronuclei was detected in the presence of a rat liver homogenate (S9). Est-Ep and Eth-Ep also induced gene mutations. Our analyses indicated low mutagenic potentials of siloranes; however, some oxiranes induced strong effects at two genetic endpoints.     

Hygiene and methods of decontamination, disinfection and sterilization in dental offices in Yaounde]

Hygiene and asepsis of the dental office depend on medical ethics and legal obligation. The survey done with the participation of 33 practitioners over the 42 practicing in Yaounde allows apprehending the reality of the daily hygiene. The ways of cleaning, decontamination, disinfection or of sterilization of the premises, the dental equipment and instruments, hand-washing, disposable materials and the vaccination protection of the practitioners were analyzed. The cleaning of the floor and door mats is daily (100%); disinfection is done daily in 83% of the departments in all of the centers. The cleaning and disinfection of the dental chair is daily and is done using soap (23%) and/or bleaching-water (56%). Cleaning or disinfection of the suction machine is done with soap (24%) or with bleaching-water (47%). The hand-pieces and the turbines are cleaned and/or disinfected after each usage in (94%) with alcohol (17%) or with bleaching-water (32%) and sterilized with a heat sterilizer (45%), an autoclave(40%) or cold disinfected(15%). The frequency of the treatment of the instruments is well-respected (83%). Nevertheless the products used are very varied and are not always used in the prescribed order. Hand-washing is systematic after each patient; 50% of the practitioners use soap bars or powered soap and 50% use an antiseptic or a disinfectant solutions. With the regard to the vaccination, only 3 practitioners were properly vaccinated against hepatitis B, tetanus, diphtheria, poliomyelitis and tuberculosis. With regard to the protection of the practitioners, 72% do not wear caps, 56% do not wear eyeglasses, 40% do not wear masks, 95% do not use rubber dams, 56% do not disinfect the radiographic films and 37% do not disinfect the impressions; the habitual attire consists of a smock worn over street clothes (78%) and street shoes (90%). The debris is burnt in 35% of the centers. Better knowledge of the different stages (cleaning, decontamination, disinfection or sterilization and the products used, absolute respect of the disposable materials, optimal vaccination protection and the elaboration of the correct procedures written and posted up in the different departments are fundamental points for quality treatment. As a matter of fact, negligence and ignorance of the rules of hygiene and asepsis should not be part and parcel of the therapeutic hazard in the dental department.     

Surgical mandibular advancement and changes in uvuloglossopharyngeal morphology and head posture: a short- and long-term cephalometric study in males

The aim of the present study was to investigate, by means of an extensive cephalometric examination, the alterations which took place in hyoid bone position, head posture, position and morphology of the soft palate, and tongue and sagittal dimensions of the pharyngeal airway after mandibular advancement osteotomy for the correction of mandibular retrognathism. The sample consisted only of adult males who underwent mandibular advancement by bilateral sagittal ramus split osteotomy (BSRO) with rigid fixation. Profile cephalograms were obtained 1-3 days before surgery (20 subjects), and 6 months (20 subjects) and 3 years (19 subjects) after the surgery. Statistical evaluation was performed by paired Student's t-test and Pearson product moment correlation analysis. At the short-term follow-up, hyoid bone and vallecula assumed a more superior (AH perpendicular FH, AH perpendicular ML, AH perpendicular S, V perpendicular FH) and anterior position (AH-C3 Hor, V-C3), which was maintained at the long-term follow-up. The soft palate (NL/PM-U) became more upright at the short-term follow-up. The tongue demonstrated a transient increase in height (H perpendicular VT) and a less upright position (VT/FH) at the long-term observation. In addition, a more upright cervical spine (OPT/HOR, CVT/HOR) was recorded at the long-term follow-up. The pharyngeal airway space at the level of the oropharynx (U-MPW) and the retroglossal space at the base of the tongue (PASmin) showed an increase in the sagittal dimension at the short-term follow-up. Significant widening at the PASmin level was sustained at the long-term follow-up, indicating that mandibular advancement osteotomy could increase airway patency and be a treatment approach for sleep apnoea in selected patients.     

Dental and oral radiographic findings in first-year university students in 1982 and 2002 in Helsinki, Finland

OBJECTIVE: This study is part of a larger research program, at the Finnish Student Health Service in Helsinki, in which changes in the dental and oral health of first-year university students (born in Helsinki) in the years 1982 and 2002 were compared. MATERIAL AND METHODS: Panoramic radiographs were taken of 176 students in 1982, mean age 19.8 years (SD+/-0.7), and of 231 in 2002, mean age 20.2 (SD+/-0.7). DMFT index, caries and periapical changes, alveolar bone resorption, wisdom teeth, supernumerary, missing, and persisting deciduous teeth were evaluated from the radiographs. The chi-squared test and non-parametric tests were used to analyze the statistical significance of differences between the study groups and between genders. RESULTS: The DMFT index diminished from 11.0 (SD +/- 4.2) to 2.9 (SD +/- 3.3) (p < 0.0001). In 2002, 27.9% of the students had a DMFT index of zero (in 1982, 0%, p < 0.000). The mean number of endodontically treated teeth diminished from 0.1 to 0.03 (p < 0.05). The number of impacted wisdom teeth increased in males from mean 0.41 to 0.69 (p < 0.05). CONCLUSIONS: An improvement in dental health was obvious in the year 2002. The favorable change in DMFT index is a trend that has been going on for several decades in Finland, probably as a result of the use of fluorides and better education in dental hygiene. The change might also be connected with improved general health.     

Diplopia and enophthalmos in blowout fractures

The aim of this study was to compare the changes of diplopia and enophthalmos in patients with blowout fractures. Three hundred sixty-two patients who presented with blowout fractures between March 2006 and February 2011 were analyzed. The sequential time changes of diplopia and enophthalmos were measured in the operated group and the observed group according to (1) the duration of preoperative observation (early: within 7 days, late: 8-14 days, delayed: >15 days); (2) the defect size (minimal: <1 cm(2), small: 1.1-2.0 cm, medium: 2.1-3.0 cm(2), large: >3.0 cm(2)); and (3) the age of the patients (<20, 21-40, 41-60, >61 years).Among the 362 patients, 242 (66.9%) had an operation, and 120 (33.1%) did not. The duration of preoperative observation did not affect the postoperative diplopia or enophthalmos. There were significant differences of enophthalmos among the operated groups with a different defect size at the preoperative period (P = 0.036 [Pearson χ(2)]). There were significant differences of diplopia among the operated groups with different defect sizes at the 6 months' follow-up period (P = 0.014 [Pearson χ(2)]). The diplopia in the older age group (>60 years) was significantly greater than that of the other 3 groups at 6 months (P = 0.023) and at 12 months (P = 0.023, [Pearson χ(2)]).We think surgery should be delayed until the swelling is decreased unless the medial rectus muscle is incarcerated. We also think that the defect size is not an important factor for whether to perform surgery. We think that the reason for the greater diplopia in the older age group is that the adaptation of binocular convergence is decreased in the older age group.     

Fluoride uptake and development of artificial erosions in bleached and fluoridated enamel in vitro

The aim of the present in vitro study was to evaluate the effect of carbamide peroxide (CP) bleaching on fluoride uptake in enamel. Additionally, the susceptibility for erosion in bleached and fluoridated enamel was tested. Each four enamel specimens were prepared from 44 bovine incisors. The four samples gained from each tooth were distributed among four groups (A-D) of 44 specimens each: A: (unbleached/unfluoridated) served for determination of baseline fluoride concentration; B: (unbleached/fluoridated) four times in 2000 ppm NaF solution (2 min); C: (bleached/unfluoridated) four times in 10% CP (8 h); D: (bleached/fluoridated) four times in 10% CP and fluoridation. In 22 specimens of each group both KOH-soluble and structurally bound fluoride were determined in the outermost 30 micro m of the enamel. In the remaining specimens erosions were induced by immersing the samples in 5 mL of 1% citric acid (20 min) and microhardness was evaluated before and after demineralization. Statistical analysis showed that KOH-soluble fluoride uptake was similar for group B and D specimens. Structurally bound fluoride uptake after fluoride application in unbleached samples was significantly higher than in bleached ones. Bleaching only resulted in a highly significant fluoride loss. In all samples erosion caused a significant microhardness loss. The study showed that pre-treatment of enamel with CP followed by fluoridation does not improve erosive resistance. Moreover the study reveals that CP treatment decreases concentration of structurally bound fluoride in enamel which could not be outweighed by fluoridation with 2000 ppm NaF. It is concluded that it is not feasible to improve fluoride uptake in enamel with a pre-treatment with 10% CP.