Determinants of Iranian dentists’ behaviour regarding infection control

Abstract

Aim: To evaluate the determinants of Iranian dentists’ behaviour regarding infection control (IC). Design: A cross-sectional questionnaire survey. Setting: Iranian general dental practitioners (GDP) participating in a national dental congress. Methods: The GDPs filled in a self-administered questionnaire containing questions regarding their attitudes towards and their behaviour on several aspects of IC. Background factors included GDP’s year of birth, gender, and work-related factors. Statistical evaluation employed the Chi-square test, Cronbach alpha, and regression analysis. Results: In total, 479 GDPs returned the questionnaire. Their mean age was 38.6 years (SD = 9.4) and 53% were men. The vast majority of the GDPs had positive attitudes towards the inquired after IC criteria with no statistical difference based on the GDP’s background characteristics. Of all respondents, >70% reported that they inform the laboratory about the infection status of the sent items, disinfect impressions before sending to the laboratory, and wash patients’ mouths before working with high-speed or ultrasonic devices. Adherence to all the studied IC criteria was reported by 10% of the respondents; more frequently by younger GDPs and those with fewer experience years (P < 0.05). Conclusion: Greater emphasis on infection control programmes in dentists’ education is called for especially in continuing education.

INTRODUCTION

The emergence of life-threatening infections highlights the need for efficient infection control practices in health care facilities. Failure to adhere to infection control measures leads to the spread of pathogens which influence the health of both the healthcare personnel and the community. Due to their frequent contact with patients’ oral and dental tissues, dentists are at risk for occupational exposure to bloodborne pathogens, such as hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV). Exposures may occur through needlesticks or from other sharp instruments contaminated with infected blood or through contact of the eye, nose, mouth, or skin with a patient’s blood. Consequently, the issue of cross infection becomes an integral part of dental practice and a major concern both to public and dentists themselves.

Several professional health agencies such as the Centers for Disease Control and Prevention (CDC), Occupational Safety and Health Administration (OSHA), American Dental Association (ADA) in the United States and National Institute of Health and Clinical Excellence (NICE) in the United Kingdom have issued specific recommendations to minimise the risk of cross infection in dental practice. These guidelines suggest routine use of gloves and masks, sterilisation of dental instruments, vaccination against HBV, and the universal (standard) precautions¹.

Dentists’ level of knowledge, attitude and adherence to infection control programmes have been studied in different parts of the world2., 3., 4., 5., 6., 7.. These investigations indicate poor adherence of dentists to the standard infection control guidelines6., 7., 8. and limitations in dentists’ knowledge regarding some aspects of infection control⁵ such as hand hygiene practices⁹, modes of transmission of infectious diseases⁸, and the risk of infection from needle stick injuries7., 10..

Implementation of infection control practices is influenced by various dentist- and practice-related factors. Lack of concern regarding potential personal risk, costs of infection control procedures¹¹, limited access to required material, and practicing in public clinics⁸ have been indicated as barriers to comply with infection control practices among dentists. The objective of this study was to assess the determinants of Iranian dentists’ behaviour regarding infection control.

MATERIAL AND METHODS

The present data were gathered by means of a self-administered questionnaire distributed to the Iranian general dental practitioners (GDP) who attended in a nationwide dental congress on infection control in Tehran, Iran, in April 2009. The respondents completed the questionnaire, which was included in the congress documents, and returned it anonymously by the end of the congress. Background information covered each dentist’s year of birth, gender, and work-related factors.

Assessment of dentists’ attitudes towards infection control

Dentists’ attitude towards infection control was inquired by the following question ‘how important do you evaluate the following infection control criteria in your clinical practice?’ the criteria included sterilisation, vaccination, protective wearing, waste disposal, disinfectants, and, working with sharp devices. The answer was given on a 5-point Likert scale ranging from ‘Very much’ to ‘Very little’. For the analysis, answers ‘Very much’ and ‘Much’ were regarded as positive attitudes.

Assessment of dentists’ behaviour on infection control

The dentists were asked, by means of five separate questions, to indicate if they accomplish the following infection control criteria in their practice:

• •Using biological monitoring system
• •Using proper working gloves when washing infected tools and instruments
• •Washing patients’ mouths before working with high-speed or ultrasonic devices
• •Disinfecting impressions before sending to the laboratory
• •Informing the laboratory about the contamination of sent items.

The answers were yes/no and adherence to the all above criteria was calculated for those who answered yes to each of the five questions.

Work-related factors included:

• •Practice type (private or public)
• •Years in practice (years since graduation)
• •Practice hours per day and working load (average number of patients visited per day).

Respondents

Of all participating dentists, 479 returned the questionnaire. Their mean age was 38.6 years (SD = 9.4) and 53% were men with the majority of the dentists in the private sector. A distinct gender difference was evident in the dentists’ personal and work-related characteristics in which men were older, practiced for a great time each day and saw more patients per day than women (P < 0.001). Respondents’ background information appears separately for men and women in Table 1.

Table 1.

Distributions (%) of the responding Iranian dentists (n = 479) by background and professional factors, separately for men (n = 253) and women (n = 226)

	All	Men	Women	P-value*
Age in years
<40	49	34	65	<0.001
40–50	44	53	34
≥51	7	13	1
Practice hour/day
1–7	60	42	80	<0.001
≥8	40	58	20
Practice sector
Private	72	87	56	<0.001
Public	28	13	44
Years in practice
<10	45	56	61	<0.001
10–20	43	32	32
≥21	12	12	7
Average number of visited patient/day
<10	57	47	68	<0.001
10–19	35	41	27
≥20	8	12	5
Self-assessed knowledge on infection control
>Medium	42	47	36	0.01
≤Medium	58	53	64

^*Statistical evaluation of differences by gender: the Chi-square test.

Statistical evaluation

The differences in frequencies between the dentist subgroups were tested by the Chi-square test. To assess the relationships between attitude and behaviour items separately, Cronbach alpha was calculated which was 0.80 for the attitude items and 0.49 for the behaviour items.

To evaluate factors related to infection control behaviour, similar logistic regression models were fitted to the data to explain adherence to the five infection control measures; gender, age, practice hours per day, self-assessed knowledge and scored attitude on infection control, served as covariates. The corresponding odds ratios (OR) and their 95% confidence intervals (95% CI) were defined.

RESULTS

Figure 1 shows the percentages of dentists who reported that the infection control items are important ‘very much’ or ‘much’ to them. The vast majority of dentists had positive attitudes towards the importance of sterilisation, protective work-wear, vaccination, disinfectants, and correct handling of sharp devices. No statistical difference was found on these attitude items based on the dentists’ background characteristics.

Figure 1.

Percentages of Iranian dentists (n = 479) selecting ‘very much’ and ‘much’ for the question ‘how important do you evaluate the following infection control methods in your clinical practice?’

The dentists’ reported behaviour on the five recommended infection control criteria is shown in Figure 2. More than 70% of the dentists reported that they inform the laboratory about the infection status of the sent items, disinfect impressions before sending to the laboratory, and wash patients’ mouths before working with high-speed or ultrasonic devices. Among the five criteria, the lowest compliance was for the item ‘using biological monitoring system in the practice’ at 26% adherence. Of all the responding dentists, 10% reported that they adhere to the five criteria (Figure 2).

Figure 2.

Percentages of Iranian dentists (n = 479) complying with various recommended infection control.

Younger more than older dentists and those dentists with fewer years experience than those with higher experience years reported ‘washing patients’ mouth before working with high-speed or ultrasonic devices’, ‘using biological monitoring system in the practice’, and showed full adherence to all the studied criteria (P < 0.05). The dentists with a working load of <10 patient per day more frequently than those with higher working load, reported using a biological monitoring system in the practice and informing the laboratory about the infection status of sent items (P < 0.05).

Table 2 shows the results of the four similar logistic regression models explaining factors related to the dentists complying with various infection control criteria. The first model was to estimate dentists complying with all of the five recommended infection control criteria. That appeared to be more likely for female dentists (OR = 2.4, 95% CI = 1.0–5.4) and those with more positive attitudes toward infection control (OR = 1.2, 95% CI = 1.0–1.4). More positive attitudes toward infection control (OR = 1.0–1.2) and higher scores for self-assessed knowledge on infection control (OR = 1.5–1.8) were major factors which explained dentists complying with washing patients’ mouths, disinfecting impressions before sending to the laboratory, and using biological monitoring system in the practice.

Table 2.

Determinants for complying with various recommended infection control criteria among Iranian dentists (n = 479), as assessed by means of four similar logistic regression models

	E.S.	S.E.	OR	95% CI	P-value
Adherence to five*recommended infection control criteria (0 = no, 1 = yes)
Gender (0 = male, 1 = female)	0.89	0.41	2.4	1.0–5.4	0.03
Age (years)	0.06	0.02	1.0	1.0–1.1	<0.001
Practice hour/day	0.11	0.07	1.1	0.9–1.3	0.12
Scored attitude towards infection control	0.20	0.08	1.2	1.0–1.4	0.01
Self-assessed knowledge on infection control	0.34	0.28	1.41	0.8–2.4	0.21
Constant and goodness of fit† (P)	−12.9	2.85			P = 0.51
Disinfecting impressions before sending to the laboratory (0 = no, 1 = yes)
Gender (0 = male, 1 = female)	0.28	0.28	1.3	0.7–2.3	0.31
Age (years)	0.02	0.01	1.0	0.9–1.0	0.11
Practice hour/day	0.06	0.05	1.0	0.9–1.1	0.21
Scored attitude towards infection control	0.09	0.04	1.1	1.0–1.2	0.01
Self-assessed knowledge on infection control	0.49	0.18	1.6	1.1–2.3	0.007
Constant and goodness of fit† (P)	−4.66	1.54			P = 0.47
Washing patients’ mouth before working with high-speed or ultrasonic devices (0 = no, 1 = yes)
Gender (0 = male, 1 = female)	0.53	0.28	1.7	0.9–2.9	0.05
Age (years)	0.06	0.01	1.0	1.0–1.1	<0.001
Practice hour/day	0.07	0.05	1.0	0.9–1.1	0.16
Scored attitude towards infection control	0.06	0.03	1.0	0.9–1.1	0.07
Self-assessed knowledge on infection control	0.39	0.17	1.5	1.0–2.1	0.02
Constant and goodness of fit† (P)	−5.15	1.50			P = 0.76
Using ‘Biological Monitoring System’ for sterilization in the practice (0 = no, 1 = yes)
Gender (0 = male, 1 = female)	0.26	0.28	1.3	0.7–2.2	0.34
Age (years)	0.04	0.01	1.0	1.0–1.0	0.001
Practice hour/day	0.04	0.05	1.0	0.9–1.1	0.35
Scored attitude towards infection control	0.17	0.05	1.2	1.0–1.3	0.001
Self-assessed knowledge on infection control	0.60	0.19	1.8	1.2–2.6	0.002
Constant and goodness of fit† (P)	−10.1	1.88			P = 0.34

^*Including: Using biological monitoring system, Using proper working glove when washing infected tools and instruments, Washing patients’ mouth before working with high-speed or ultrasonic devices, Disinfecting impressions before sending to the laboratory, and Informing the laboratory about the contamination of sent items.

^†Hosmer–Lemeshow test.

DISCUSSION

Almost all of the present dentists showed positive attitudes towards infection control. However, compliance with all selected infection control criteria was a rare condition. Dentists’ attitudes regarding various aspects of infection control in this study is in line with the findings of studies in other countries9., 12. which presents overall positive attitudes of dentists regarding infection control criteria. This may provide a good basis for their practice since attitudes are an important prerequisite for action13., 14..

Despite clear guidelines and recommendations regarding infection control in dental practices from recognised international15., 16. and national¹⁷ organisations, dentists adherence to combination of all studied criteria was poor in this study. This rate (10%) is, however, comparable with the finding of the study on Jordanian dentists⁶ and Canadian dentists³ in which about 14% and 6%, respectively were found to be fully compliant with the studied infection control procedures, although the number of studied infection control criteria in the two latter studies was greater than the present study. Infection control practices must be an essential part of dentists’ work to provide a safe environment for both dental staff and patients. More investigations are, therefore, needed to shed light on factors which deter dentists from following all standard infection control criteria.

Communication between dental clinic and dental laboratory about the disinfecting procedure provide a reliable mean for infection control. More than two-thirds of the dentists reported that they inform the laboratory about the contamination of sent items and disinfect impressions before sending to the laboratory. This shows that they have great concerns about transmission of infection between clinic and laboratory. Findings of a study on disinfection in United States dental laboratories showed weak communication between dentists and laboratories about the disinfection procedures in which less than half of the 400 surveyed laboratories were aware of the disinfection status of impressions they had received from dental clinics¹⁸.

Using antimicrobial mouthwashes for patients prior to intraoral procedures can prevent possible disease transmission by minimising the microbial content of aerosols generated during dental treatments19., 20.. This practice was reported by a majority of the present Iranian dentists (75%), showing a high level of knowledge and adoption. This is far above the rate of Canadian dentists of whom no more than 5% reported to adhere to this criterion²¹.

In order to ensure the effectiveness of dental office sterilisers, regular use of biological indicators is essential²². In this study, however, less than a quarter of the dentists reported following this guideline. Compared to the findings of similar studies on Canadian dentists (50–91%)²¹, dentists in the USA (100%)²³ and in Ireland (89%)²⁴ this rate seems to be very low which indicates an underestimation of the importance of sterilisation by the dentists in the present study and pour doubt on the quality of sterilisation in their practices.

The findings of this study showed higher compliance of younger dentists with infection control procedures which is consistent with the findings of a study on dentists in Jordan⁶. This may be due to the impact of dentists’ recent education and practice in dental school which requires complete adherence to standard infection control protocols. Moreover, as it is clear in the results of the logistic regression models, adherence to infection control criteria is more likely among female dentists. This is again in line with the findings of the study on Jordanian dentists⁶.

This study employed participants of a dental meeting as sample subjects. Unfortunately, a mail survey was not possible since reliable data on registered dentists in Iran are not available. Thus the present method remained as the most practical way to reach the dentists. The characteristics of questionnaire surveys, which rely on self reporting and therefore raise the probability of social desirable answers²⁵, are another source of limitation for this study. In addition, the present results may have led us to an overoptimistic picture of real situation since dentists who participated in the meeting and responded to the questionnaire may have been more concerned about infection control issues than those who did not attend and respond.

The present findings call for greater emphasis on infection control programmes in dentists’ education specially in continuing education.

Acknowledgements

We wish to thank all the dentists for their participation.