Refractive, biometric and topographic changes among Portuguese university science students: a 3-year longitudinal study

PURPOSE

The aim of this study was to investigate the changes in refractive, biometric and topographic ocular parameters among university students in Portugal during a 3-year period.

METHODS

A 3-year longitudinal study comprised 118 Portuguese university students from the School of Science (34 males and 84 females; mean age 20.6 +/- 2.3 years). Ocular refraction, corneal curvature (CR) and eccentricity, and A-scan biometry were conducted under cycloplegia. The sphero-cylindrical refractive results were converted into vector representations (M, J(0) and J(45)) for statistical analysis. Myopia was defined as M < or = -0.50 D, emmetropia as M > -0.50 D and < +0.50 D and hyperopia as M > or = +0.50 D.

RESULTS

At the beginning of the study sphero-cylindrical refraction (M) ranged from -6.75 to +3.00 D, with a mean value of 0.23 +/- 1.46 D [mean +/- standard deviation (S.D.)]. Eighty-three students presented astigmatism with a mean value (+/-S.D.) of -0.52 +/- 0.41 D, and a maximum of -2.25 D. After 3 years the mean refractive change for the M component was -0.29 +/- 0.38 D (p < 0.001) and non-significant changes of 0.02 +/- 0.16 D (p = 0.281) for the J(0) component and 0.01 +/- 0.09 D (p = 0.784) for the J(45) component. Prevalence of myopia increased by 5.1%, while the prevalence of hyperopia decreased by 9.4%. Myopia progression > or =0.5 D was observed in 22% of the population. Axial length, vitreous chamber depth and lens thickness increased significantly while anterior chamber depth and central CR did not change significantly.

CONCLUSIONS

This study shows a change in refraction towards myopia accompanied by a vitreous chamber elongation in a Portuguese population comprising science students during the first three years of their university course. Younger students were more likely to show clinically significant myopia progression.

Characterization of inflammatory cells in oral paracoccidioidomycosis

Paracoccidioidomycosis (Pmycosis) is one of the most common deep mycoses in many regions of Latin America, particularly in Brazil. Microscopically, it shows granulomatous inflammatory reaction with giant cells, macrophages, lymphocytes, plasma cells, polymorphonuclear neutrophilic leukocytes, and eosinophils. The purpose of this study was to assess the distribution of inflammatory cells in oral Pmycosis. Fifteen cases of oral Pmycosis were studied by immunohistochemistry for the presence of macrophages, CD4(+) and CD8(+) lymphocytes, CD20(+), CD15(+), and S100(+) cells. Macrophages were the main cells in well-organized granulomas and non-granulomatous areas. The CD4 phenotype was predominant in well-organized granulomas and a balance between CD4(+) and CD8(+) cells was observed in non-granulomatous areas. Dendritic, S100(+) cells were found mainly in the epithelium, in subepithelial connective tissue, and at the periphery of organized granulomas. CD15(+) cells were concentrated mainly in areas of intraepithelial microabscess and ulceration. Macrophages and T cells are the predominant cells in oral Pmycosis. Well-organized granulomas contain fewer yeast particles, indicating a more effective host immune response. Better understanding of the histopathological changes in oral Pmycosis might help determine treatment, severity and systemic involvement of the disease.

Technical Note: Accuracy and repeatability of a new portable ultrasound pachymeter

PURPOSE

To assess the accuracy and repeatability of central corneal thickness (CCT) measurements taken with a new portable ultrasound (US) pachymeter.

METHODS

Central thickness measurements were taken with a portable pachymeter (SP-100 Handy; Tomey, Nagoya, Japan) and a conventional US pachymeter (Nidek UP-1000; Nidek Technologies, Gamagori, Japan) from 57 right corneas of 57 young adults (19 males, 38 females) aged 18-44 years (mean +/- S.D., 22.95 +/- 3.92). Three repeated measures were obtained and then compared to obtain the repeatability of each instrument and the agreement between the pachymeters. The three readings taken with the portable pachymeter were compared against each other in order to evaluate intra-session repeatability and bias of each individual measurement with respect to the mean of three.

RESULTS

Mean values of CCT were 537 +/- 35 microm for conventional and 534 +/- 35 microm for the new portable pachymeter. A high agreement was found between the two instruments (mean difference = 2.58 microm; 95% CI 1.41-3.75 microm) with only two eyes presenting differences larger than +/-8.6 microm which represents 95% CI in the Bland-Altman plots which represents 1.6% of the mean CCT. The first reading taken showed the highest agreement with the mean value for the portable pachymeter.

CONCLUSIONS

The instrument tested in this study is able to take reliable measurements of corneal thickness even if a single reading is considered. Intra-session repeatability was very high, as was also the agreement between the average of three readings taken with the two US pachymeters.

Age differences in central and peripheral intraocular pressure using a rebound tonometer

AIM

To evaluate the influence of age on the measurements and relationships among central and peripheral intraocular pressure (IOP) readings taken with a rebound tonometer.

METHODS

The IOPs were measured using the ICare rebound tonometer on the right eyes of 217 patients (88 men and 129 women) aged 18-85 years (mean 45.9 (SD 19.8) years), at the centre and at 2 mm from the nasal and temporal limbus along the horizontal meridian. Three age groups were established: young (< or =30 years old; n = 75), middle aged (31-60 years old; n = 77) and old patients (>60 years old; n = 65).

RESULTS

A high correlation was found between the central and peripheral IOP readings, with the central readings being higher than the peripheral ones. Higher IOP values for the central location were found in the younger patients. Older patients had significantly lower temporal IOP readings than those for the remaining two groups (p<0.001), whereas no significant differences were found among groups when IOP was measured at the central and nasal locations. A significant decrease was observed in the nasal and temporal IOP readings as the age increased (p = 0.011 and 0.006, respectively).

CONCLUSION

Older patients had lower IOP values than the middle-aged and younger patients in the temporal peripheral location. A negative correlation was found between age and IOP by rebound tonometry in the corneal periphery but not in its centre.

Non-contact tonometry synchronized with cardiac rhythm and its relationship with blood pressure

PURPOSE

The main objectives of this study were to determine the differences between non-synchronized intraocular pressure (IOP_N) and intraocular pressure readings synchronized with cardiac pulse and try to determine if these parameters are related to blood pressure values.

METHODS

One hundred and sixty-five right eyes from 165 volunteers (107 females, 58 males) aged from 19 to 73 years (mean +/- S.D., 29.93 +/- 11.17) were examined with the Nidek NT-4000, a new non-contact tonometer that allows the measurement of IOP synchronized with the cardiac rhythm. IOP measurements in the four different modes of synchronization were taken in a randomized order. Three measures of each parameter were taken and then averaged. The blood pressure was determined three times with a portable manometer and mean values of systolic and diastolic pressure and the pulse rate were computed. Mean arterial pressure (MAP) was determined as being 1/3 of systolic plus 2/3 of diastolic blood pressure.

RESULTS

The mean +/- S.D. values for the standard intraocular pressure (IOP_N: 14.76 +/- 2.86), intraocular pressure in the systolic instant or peak (IOP_P: 14.99 +/- 2.85), intraocular pressure in the middle instant between heartbeats or middle (IOP_M: 14.68 +/- 2.76), and intraocular pressure in the diastolic instant or bottom (IOP_B: 13.86 +/- 2.61) were obtained. The IOP_P was higher than the remaining values. A significant difference in mean IOP existed between IOP_B and the remaining modes of measuring (p < 0.05). Differences were statistically significant for all pair comparisons involving IOP_B. Arterial blood pressure values were systolic 125.5 +/- 14.22, diastolic 77.7 +/- 8.38 and MAP 93.64 +/- 9.44 mmHg. The pulse rate was 77.3 +/- 12.6 beats per minute. Except for the MAP (p = 0.025) there was no significant correlation between different IOP values and systolic or diastolic blood pressure, or pulse rate.

CONCLUSIONS

NT-4000 is able to differentiate IOP values when synchronized with the cardiac rhythm and those differences are expected to be within a range of +/-2.5 to +/- 3.0 mmHg. IOP_B seems to be the parameter whose value differs from the non-synchronized and the remaining synchronized parameters in a significant way. Other than a weak association with MAP, no significant correlation between IOP and BP was found. The measurements of IOP readings for the three modes are consistent with timings during the cardiac cycle and IOP pulse cycle.

The influence of cycloplegia in objective refraction

The purpose of this study was to compare refractions measured with an autorefractor and by retinoscopy with and without cycloplegia. The objective refractions were performed in 199 right eyes from 199 healthy young adults with a mean age of 21.6 +/- 2.66 years. The measurements were performed first without cycloplegia and repeated 30 min later with cycloplegia. Data were analysed using Fourier decomposition of the power profile. More negative values of component M and J(0) were given by non-cycloplegic autorefraction compared with cycloplegic autorefraction (p < 0.0001). However more positive values for the J(45) vector were given by non-cycloplegic autorefraction, although this difference was not statistically significant (p = 0.233). By retinoscopy, more negative values of component M were obtained with non-cycloplegic retinoscopy (p < 0.0001); for the cylindrical vectors J(0) and J(45) the retinoscopy without cycloplegia yields more negative values (p = 0.234; p = 0.112, respectively). Accepting that differences between cycloplegic and non-cycloplegic retinoscopy are only due to the accommodative response, the present results confirm that when performed by an experienced clinician, retinoscopy is a more reliable method to obtain the objective starting point for refraction under non-cycloplegic conditions.

Comparison of the ICareR rebound tonometer with the Goldmann tonometer in a normal population

The aim of this study was to evaluate the accuracy of measurement of intraocular pressure (IOP) using a new induction/impact rebound tonometer (ICare) in comparison with the Goldmann applanation tonometer (AT). The left eyes of 46 university students were assessed with the two tonometers, with induction tonometry being performed first. The ICare was handled by an optometrist and the Goldmann tonometer by an ophthalmologist. In this study, statistically significant differences were found when comparing the ICare rebound tonometer with applanation tonometry (AT) (p < 0.05). The mean difference between the two tonometers was 1.34 +/- 2.03 mmHg (mean +/- S.D.) and the 95% limits of agreement were +/-3.98 mmHg. A frequency distribution of the differences demonstrated that in more than 80% of cases the IOP readings differed by <3 mmHg between the ICare and the AT. In the present population the ICare overestimates the IOP value by 1.34 mmHg on average when compared with Goldmann tonometer. Nevertheless, the ICare tonometer may be helpful as a screening tool when Goldmann applanation tonometry is not applicable or not recommended, as it is able to estimate IOP within a range of +/-3.00 mmHg in more than 80% of the population.

Primary intraosseous fibrosarcoma of jaw

This paper reports one case of primary fibrosarcoma affecting the mandible in a 41-year-old woman. Microscopically, the tumor was cellularized with an intense mitotic activity, and areas of necrosis and hemorrhage, and the cells showed immunoreactivity only for vimentin, establishing the diagnosis of primary intraosseous fibrosarcoma. The patient underwent tumor surgical resection, supraomohyoid neck dissection and mandible reconstruction with fibula flap and titanium bar. She also received post-surgical radiotherapy and is in follow up for 36 months without signs of recurrence or metastases.

Peutz-Jeghers syndrome in a 14-year-old boy: case report and review of the literature

Peutz-Jeghers syndrome (PSJ) is a relatively rare but well-recognized condition, with a prevalence of approximately one in 120,000 births in the USA. It is generally inherited as an autosomal dominant trait, although 35% of cases are new mutations. This disorder is characterized by melanocytic macules on the hands, feet, peri-oral skin and oral mucosa, and multiple gastrointestinal hamartomatous polyps. People with PSJ have an increased risk for developing a variety of malignant tumours. The aim of the present study was to report one case of PSJ in a 14-year-old boy with mucocutaneous pigmentation associated with duodenal hamartomatous polyps.

Ovariectomy reduces the gelatinolytic activity and expression of matrix metalloproteinases and collagen in rat molar extraction wounds

Osteoporosis is commonly associated with estrogen deficiency. However, the mechanisms by which the lack of this hormone causes bone loss are poorly understood. The bone structure of the oral cavity seems to be affected by estrogen deficiency, since a delayed healing process after tooth extraction has been observed after ovariectomy in rats. The aim of this study was to describe the effect of the absence of estrogen on the expression and activity of matrix metalloproteinases (MMC)-2 and -9 and expression of types I and III collagens in the alveolar granulation tissue of young female rats after tooth extraction. Sixty-six, four-week-old female rats underwent bilateral ovariectomies (OVX) or sham operations. Three weeks later, both first and second mandibular molars were extracted and the animals were killed by cervical dislocation 3, 5, or 7 days after tooth extraction. The granulation tissues were collected from the extracted alveolar sockets and used for zymographic, Western blot, or reverse transcription polymerase chain reaction (RT-PCR) analysis. There was a gradual increase on the expression of all studied proteins as well as MMP-2 and -9 activities in the periods after surgery. In contrast, OVX animals showed a significant decrease in the gelatinolytic activities and expression of MMP-2 and -9 and types I and III collagens. The results presented here in suggest that the absence of estrogen may possibly contribute to the delayed alveolar wound healing by interfering with the extracellular matrix turnover.

Primary tuberculosis of the oral cavity

Tuberculosis is one of the major causes of ill health and death worldwide. Nevertheless, tuberculous lesions of the oral cavity are rare and can be a diagnostic challenge, particularly in young immunocompetent patients. Most of the cases are secondary to pulmonary disease and the primary form is uncommon. In this paper, we present a case of primary oral tuberculosis, affecting the floor of mouth in a 13-year-old Brazilian male patient.

A comparison of the ARK-700A autokeratometer and Medmont E300 corneal topographer when measuring peripheral corneal curvature

PURPOSE

The purpose of this study was to evaluate if corneal topogometry measurements as taken with the ARK-700A autokeratometer are comparable with those measured by the Medmont E300 videokeratoscope at corresponding locations.

METHODS

Central and peripheral radius and eccentricity were measured in 122 right eyes of young normal subjects using autokeratometry and videokeratoscopy, obtained in a random order.

RESULTS

Curvature measurements obtained with the ARK700A and Medmont E300 correlated well for the central cornea. Larger differences were observed between peripheral autokeratometry readings and the empirically determined corresponding locations with the videokeratoscope. Correlations between the instruments are inconsistent, resulting in unacceptable confidence intervals. Corneal eccentricity was significantly different between the instruments for the vertical (t = 2.4; p = 0.018) and for the horizontal meridians. In the first case, the difference between the averaged values was not clinically significant, but in the horizontal meridian the AK significantly overestimated eccentricity values (t = -11.5; p < 0.001) with differences which were clinically significant.

CONCLUSIONS

Central corneal curvature data obtained by ARK700A and Medmont E300 can be interchanged but the same is not true of peripheral determinations of corneal shape. ARK700A probably measures peripheral corneal shape within an elliptical region between 5 and 7 mm in diameter, with the major axis in the vertical meridian.

Oral Candida flora from Brazilian human immunodeficiency virus-infected patients in the highly active antiretroviral therapy era

One of the main opportunistic fungal infections amongst immunocompromised individuals is oral candidosis, which has been found in up to 90% of human immunodeficiency virus (HIV)-infected patients. This study employed yeasts isolated from the saliva and oral cavities of 114 HIV-infected patients living in Campinas, São Paulo. Of the isolates, 57.8% were identified as Candida albicans and 42.1% as non-C. albicans. The latter isolates were subsequently identified as C. krusei (7.5%), C. lusitaniae (5.2%), C. tropicalis (4.6%), C. parapsilosis (4.6%), C. glabrata (2.8%), C. kefyr (1.7%), C. guilliermondii (1.7%), C. intermedia (1.1%), C. norvegensis (0.5%), and Rhodotorula rubra (1.7%). Susceptibility of the isolates to amphotericin B, fluconazole, miconazole, and itraconazole was also determined by a microdilution method adopted by the National Committee for Clinical Laboratory Standards. The isolates demonstrated various susceptibilities to the antifungal agents. In particular 29 C. albicans and 13 non-C. albicans isolates showed low susceptibility to FLCZ (> 64 micro g/ml). This study revealed huge diversity of Candida species, in particular the increasing emergence of non-C. albicans associated with the oral flora of HIV-infected patients.

Clinical performance of non-contact tonometry by Reichert AT550 in glaucomatous patients

Measuring intraocular pressure (IOP) by non-contact tonometry (NCT) has been demonstrated to be a valid and reliable technique to be used in primary eye care; it is easier to use, it does not transmit infectious diseases, and it is not necessary to use anaesthetic or staining eye drops. Recently, a new NCT device has showed an excellent level of agreement with Goldmann tonometry, but there are no records of its performance in glaucomatous eyes. To rectify this, IOP was measured in twenty-two patients (44 eyes) receiving medical treatment to control elevated IOP, with AT550 and Goldmann tonometry. Mean values of IOP were 18.98 +/- 2.77 and 19.08 +/- 3.02 mmHg using Goldmann and AT550, respectively. Plots of differences against means displayed good agreement (mean difference +/- limits of agreement, -0.09 +/- 3.30); this value was not significantly different from zero (t-test for dependent samples, p = 0.709). In conclusion, IOP values as measured with the AT550 NCT are clinically comparable with those obtained with Goldmann tonometry in glaucomatous patients. This validates this NCT not only for screening of IOP but to follow-up glaucomatous patients with a rapid, non-invasive method.

Primary aspergillosis affecting the tongue of a leukemic patient

We describe a case of primary aspergillosis involving the tongue of a patient with acute myeloid leukemia. Intraoral aspergillosis is very rare and we found only 23 cases reported in the English literature. Clinically it was a 2-cm, ulcerated, grayish lesion on the dorsum of the tongue. Microscopically there was invasion of the epithelium, connective tissue and muscle of the tongue by fungal hyphae branching at 45 degrees angle. The large hyphae were easily seen by H & E stain, and were strongly positive for periodic acid-Schiff and Grocott methenamine. The patient was successfully treated with intravenous amphotericin B. Based on clinical, microscopic and culture data, the diagnosis of primary aspergillosis of the tongue was established. Invasive oral aspergillosis is a potentially lethal disease and it should be considered in immunosuppressed patients.

Transmission of HIV in the dental clinic and elsewhere

This review focuses on the risk of transmission of HIV in dental practice in developed and developing countries; and as a result of oral sex, perinatal transmission and breast feeding. Postexposure prophylaxis (PEP) and practical measures to control cross-infection with TB are also discussed. There are few data from resource-poor countries where prevalence of HIV and risk of infection are higher--issues that deserve priority. Available information indicates that the risk of HIV transmission in the dental office is very low. Transmission of HIV from three healthcare workers to patients has been confirmed, including a dentist who infected six patients. There are >300 reports (102 confirmed) of occupational transmission to healthcare workers, including nine dental workers (unconfirmed). Exposure to HIV has been reported by 0.5% dentists/year. The risk of HIV infection after percutaneous exposure (0.3%) can be reduced by 81% with zidovudine PEP. However, risk assessment is required to assess the need and appropriate regimen. The risk of HIV transmission associated with orogenital sex exists, but is considered extremely low: barrier protection is recommended. Conversely, the proportion of babies who acquire HIV from untreated HIV-seropositive mothers is 15-25% in developed countries and 25-45% in developing countries. The frequency of HIV transmission attributable to breastfeeding is 16%. Airborne transmission of TB can be avoided by the prompt referral of known/suspected cases of active TB for chemotherapy, deferral of elective procedures until patients are not infectious, and the use of appropriate standard/isolation precautions including adequate ventilation of treatment areas.

Clinical performance of the Reichert AT550: a new non-contact tonometer

The aim of the present study was to assess the level of accuracy for measurements of intra-ocular pressure (IOP) obtained with a new non-contact tonometer (NCT) the Reichert AT550. Measurements were compared against those obtained with the Reichert Xpert Plus, Goldmann applanation tonometer and Perkins tonometer. Thirty-five university students were assessed with the four tonometers in a randomised order, with non-contact tonometry performed first. Each of the four measurement devices had its own trained clinical observer. Plots of differences of IOP as a function of the mean for each pair of instruments were obtained. No statistically significant differences were found when comparing the AT550 NCT with contact applanation tonometry (AT) (p> 0.05), displaying the closest level of agreement (as represented by the lowest mean difference and the narrowest confidence interval) with the Goldmann tonometer (limits of agreement, 0.12+/-2.17). In conclusion, readings of IOP with the AT550 NCT are clinically comparable with those obtained with Goldmann tonometry in a population with IOP within the normal range.

Thalidomide: a role in oral oncology?

Thalidomide is having increasing application in the management of a wide spectrum of immunologically-mediated and infectious disorders. It is also suggested that this agent may also have be of importance in the treatment of solid and non-solid malignancies. The present article reviews the role of thalidomide in the management of malignancy and outlines its possible potential in the treatment of malignancy of the mouth.

Juvenile intraoral pleomorphic adenoma: report of five cases and review of the literature

The aim of this study is to report on five cases of intraoral pleomorphic adenoma (PA) in patients under 18 years of age and to review the literature. Intraoral salivary gland tumours were reviewed in two Brazilian institutions and five cases of PA in patients under 18 years of age were found. Clinical data were obtained from the medical records and paraffin-embedded tissues were sectioned for proliferating cell nuclear antigen (PCNA) and p53 immunohistochemical analysis. Four patients were female and one was male; two cases affected the palate, two the upper lip and one the tongue. All five patients were treated surgically and after long follow-up periods no recurrences were observed. Tumour cells were weakly positive for PCNA and negative for p53. PA should be considered in the differential diagnosis of submucosal nodules in young patients. In youngsters, PA seems to have similar biological characteristics as in adults, with low recurrence rates after surgical resection.

Molecular characterization of Candida spp. isolated from the oral cavities of patients from diverse clinical settings

Infections by Candida spp. have increased in medical importance over the past few decades. Our understanding of species identification, commensalisms, pathogenicity, person-to-person spread, and the development of antifungal resistance within specific strains has been greatly enhanced by the utilization of molecular epidemiological methodology. The aim of the current research was to assess the quantity, species and molecular characterization of oral yeast isolates from well-defined cohorts of immunocompetent patients from a diverse range of clinical settings. Oral rinse samples were assessed for the growth of yeast and degree of colonization. Isolates were defined to the species level by both phenotypic and molecular methods and strains were further genotypically subtyped. Significant variation was shown to exist in the number, species and genotypic subgroups of yeast isolated from the oral cavity in different patient groups. This variation could be attributed to the local oral conditions unique to these patient groups.

The effect of cyclosporin A on the activity of matrix metalloproteinases during the healing of rat molar extraction wounds

Cyclosporin A (CyA) is a cyclic peptide used as an immunosuppressive agent because it can block the synthesis of interleukin-2 and other cytokines produced by CD4+ lymphocytes. It is widely used for the prevention of allograft rejection and treatment of autoimmune diseases. Several side-effects of CyA treatment have been reported, among which are chronic nephrotoxicity, hepatotoxicity and neurotoxicity, lymphoproliferative neoplasms, hypertension, thromboembolic complications and gingival overgrowth. Here, using a rat molar model, it is demonstrated that CyA immunosuppression inhibits the activity of matrix metalloproteinases 2 and 9 in the early phase of granulation tissue in the healing dental socket. These observations suggest that CyA may interfere with the wound healing following dental extractions.

Regional odontodysplasia. Report of two cases

Two cases of regional odontodysplasia in girls are reported; one affected the lower incisors, and the other the left maxilla. The first case was radiographically followed over a 6-year period, during which time the ghost teeth exhibited significant dentin formation, along with a resultant decrease in pulp size and relative normalization of the radicular anatomy. The second case involved the deciduous molars and the first permanent molar. In addition to tooth alterations, both cases exhibited many odontogenic epithelial islands and extensive areas of calcification in the mucosa. Diagnosis, causes, and treatment are discussed in the light of recent data.

Knowledge of and attitudes about blood-borne viruses and infection control in Brazilian dental practice

OBJECTIVE

To determine whether there were any recent changes in hepatitis B immunisation of dental staff, infection control or understanding of viral infections in Brazilian dentists.

DESIGN

A randomised survey was conducted on 740 dentists attending the National Dental Congress in Sao Paulo, Brazil in 1994.

SUBJECTS AND METHODS

The 740 dentists were questioned as to the presence of various viruses in saliva, the perceived risks of dental staff and long-term sequelae, the availability and uptake of vaccines, willingness to treat virus-infected persons, and means of infection control. Nearly 69% of respondents were female dentists, of mean age 30 years. Results were compared with a similar survey from 1990.

RESULTS

Most respondents knew that HIV and hepatitis viruses could appear in saliva and almost all knew of infective risks from hepatitis B (HBV), and the availability of the vaccine. Less than half knew of the association of HBV with liver cancer. There was a four-fold increase in those vaccinated against HBV since the low figure of 9% in 1990. Nearly two-thirds of respondents perceived an occupational risk to dental staff from HIV, and a similar proportion were also unwilling to treat virus-infected persons. A similar proportion also used chemical disinfection for some dental instruments.

CONCLUSIONS

The results show little improvement over a 4-year period except a much greater proportion of dentists were immunised against HBV. However, still only one third of dentists had been vaccinated, in a country with a high prevalence of infection in the general population.