Adherence to and acceptability of three alcohol‐free, antiseptic oral rinses: A community‐based pilot randomized controlled trial among pregnant women in rural Nepal

Abstract Objectives Antiseptic oral rinses have been evaluated as interventions to reduce the risk of adverse pregnancy outcomes associated with periodontal disease in pregnant women. Oral rinse use is not common in Nepal or other countries in South Asia, where the prevalence of adverse pregnancy outcomes is high. Understanding whether pregnant women in rural communities in this region would incorporate rinse use into their daily teeth cleaning routine is an important prerequisite to future research on this topic in South Asia. Methods We conducted a community‐based pilot randomized controlled trial of three alcohol‐free, antiseptic oral rinses among pregnant women <22 weeks pregnant in rural Nepal with the aim of assessing rinse acceptability, adherence, and effect on clinical periodontal measures. At baseline, participants underwent a clinical periodontal examination, and then were classified as healthy or having at least mild gingivitis (≥1 site with probing depth (PD) 3 mm and bleeding on probing (BOP) or ≥4 mm (PD)). Participants were stratified by periodontal status and randomized within each exposure category to chlorhexidine (CHX) (0.12%), cetylpyridinium chloride (CPC) (0.05%), salt and water (NaCl), or control (no rinse). Rinse participants were followed weekly for 12 weeks, and all participants underwent a second periodontal examination and answered a questionnaire. Results Pregnant women in the rural Terai region of Nepal showed high adherence to (mean weekly rinse use: 185 mL (standard deviation: 66 mL)) a recommended 210 mL and acceptability of all three rinses. Participants reported greater frequency of tooth brushing with toothpaste and improvements in other recommended oral hygiene behaviours. CHX significantly reduced rates of gingivitis (defined as a participant with BOP ≥ 10% of sites) and the extent of BOP (gingivitis at the end of follow‐up for CHX vs control: RR 0.37, 95% CI: 0.16, 0.84). CPC and NaCl rinse groups had rates of gingivitis and extent of BOP similar to the control group (gingivitis at the end of follow‐up for CPC: RR 0.81, 95% CI: 0.47, 1.38; NaCl: RR 0.92, 95% CI: 0.55, 1.56). Conclusions Adherence to and acceptability of three alcohol‐free, antiseptic oral rinses were high among pregnant women in rural Nepal. Among participants with mild gingivitis at baseline, CHX rinse was most effective at reducing signs of disease compared to the control group. Oral rinse should be considered as a supplement to current oral self‐care routines for pregnant women in settings where rinse use is uncommon and access to oral health services is limited.


| INTRODUC TI ON
Periodontal disease in pregnant women has been posited by some observational studies as a possible risk factor for adverse pregnancy outcomes, including preterm birth. 1 Hypothesized mechanisms behind this association include haematogenic translocation of periodontal pathogens or their by-products to the foetal-placental unit, action of inflammatory mediators in the periodontium, or a confounding genetic hyper-inflammatory phenotype. 2,3 Yet meta-analyses of trials have not reported clear evidence of an effect of periodontal treatment vs no treatment on preterm birth (RR 0.87, 95% CI: 0.70, 1.10). [4][5][6][7] Further, a meta-analysis of studies evaluating the efficacy of periodontal therapy to prevent preterm birth, low birth weight, and perinatal mortality, found evidence of publication bias for each of these outcomes. 8 Systematic reviews have attributed inconsistent findings among trials to heterogeneity between studies, low methodological quality, and differences in when during pregnancy the intervention was delivered. 9 One meta-analysis, however, reported a significant reduction in risk of preterm birth in a sub-group of five studies using a chlorhexidine rinse (CHX) as a co-intervention with periodontal treatment (RR 0.69, 95% CI, 0.50, 0.95). 10 In another review, among a sub-group of four studies, a significant effect of treatment in reduction of preterm was found for women with high risk of the outcome (defined as incidence of preterm ≥15%) (RR 0.66, 95% CI: 0.54, 0.80). 7 Antiseptic oral rinses are known to reduce gingival bleeding, inflammation, and the presence of aggressive periodontal pathogens associated with progression of periodontal disease, including P gingivalis and A actinomycetemcomitans. [11][12][13][14][15] Studies have shown CHX to result in greater improvements in gingival index scores and other clinical measures than rinses with different agents, but this comes with a greater risk of side-effects, such as tooth staining and transient taste loss; these do not commonly occur with other rinses, such as cetylpyridinium chloride (CPC). 16 Salt and water rinse (NaCl), while not as effective as CHX or other agents, has shown some antimicrobial effect and would be a cheaper and easier option. 17 An antimicrobial oral rinse, along with oral hygiene instruction, as an intervention for preterm birth and other adverse pregnancy outcomes would be appealing in many low-and middle-income settings, where access to quality oral care is limited. Use of antiseptic oral rinses is not common in Nepal or other countries in South Asia. 18,19 It is unclear whether pregnant women in rural communities in this region would take up the practice of daily rinse use as part of their oral self-care routine.
We conducted a community-based randomized controlled trial of three alcohol-free, antiseptic oral rinses, including CHX, CPC, and NaCl. Our primary aim was to assess levels of adherence to and acceptability of these three oral rinses over a 12-week period among pregnant women in rural Sarlahi District, Nepal. A secondary aim of the trial was to evaluate changes in clinical periodontal measurements between examinations at baseline and the end of the 12-week follow-up period in both healthy participants and participants with signs of mild gingivitis by rinse assignment.

| ME THODS
We conducted a randomized controlled trial nested within the Nepal Oral Health Cohort Study (NOHCS), a community-based, prospective cohort study of maternal gingivitis and adverse pregnancy outcomes in a sub-area of Sarlahi District, Nepal, between January and November 2016. NOHCS participants were identified and determined eligible using the infrastructure of a large community-based randomized trial, the Nepal Oil Massage Study (NOMS) (NCT01177111), which was actively enrolling a population-based sample of pregnant women in this study area.
Pregnant women <22 weeks gestation from across eight village development committees (VDCs) in Sarlahi District were enrolled in the trial and followed for 12 weeks. A clinical periodontal examination conducted at the enrolment visit was used to assign participants into two groups -healthy and at least mild gingivitis. Within the healthy group, we randomly assigned 25 participants to one of two rinse groups (CPC, NaCl, and a control group). Within the disease group, we randomly assigned 25 participants to one of three rinse rates of gingivitis and extent of BOP similar to the control group (gingivitis at the end of follow-up for CPC: RR 0.81, 95% CI: 0.47, 1.38; NaCl: RR 0.92, 95% CI: 0.55, 1.56).
Conclusions: Adherence to and acceptability of three alcohol-free, antiseptic oral rinses were high among pregnant women in rural Nepal. Among participants with mild gingivitis at baseline, CHX rinse was most effective at reducing signs of disease compared to the control group. Oral rinse should be considered as a supplement to current oral self-care routines for pregnant women in settings where rinse use is uncommon and access to oral health services is limited.
gingivitis, oral health, oral hygiene, plaque control, public health groups (CPC, NaCl, and CHX) or the control. CHX rinse was not used in healthy participants as this rinse is typically indicated as a therapeutic intervention only due to its strong side-effects. In summary, group assignments by disease status were planned as the following: healthy (n = 25 CPC, n = 25 NaCl, n = 25 control) and disease (n = 25 CHX, n = 25 CPC, n = 25 NaCl, n = 25 control) for a total of 175 participants (Figure 1).
At the enrolment visit, all participants were consented for the trial, underwent a periodontal examination, were assigned to control or a rinse group, and received oral hygiene instructions, including a brushing demonstration. Those assigned to a rinse group also received their first batch of rinse at this time, and they were instructed not to dispose of the oral rinse containers after use.
After enrolment, participants in the three rinse groups were visited weekly for 12 weeks. Adherence was measured by observing the amount of rinse remaining in containers delivered the previous week and through questions about daily use in the previous 7 days.
Participants were also asked basic questions on the acceptability of the rinse. Early exit from the trial occurred when participants either had the birth outcome (live birth, stillbirth, miscarriage or abortion) or refused further participation. At their 12th weekly visit, or at the time of early exit from the trial, all participants (both rinse and control groups) underwent a second oral health clinical examination. At this final visit, the women in the three rinse arms also answered a short questionnaire to gather additional information on oral rinse acceptability and adherence. Control participants were asked questions on oral hygiene behaviours during the 12-week period.
All study visits, including oral health clinical examination, were performed in participant homes by five auxiliary nurse midwives who were trained by an experienced dentist (NKA) from the Department of Dentistry, Institute of Medicine, Tribhuvan University, Kathmandu, Nepal. The auxiliary nurse midwives conducted a full-mouth periodontal examination, including measurement of PD at six sites per tooth (disto-, mid-, and mesial-aspects of buccal and lingual surfaces) and the CEJ-GM distance on two sites per tooth (mid-buccal and lingual aspects), excluding third molars. After probing each quadrant, the auxiliary nurse midwives assessed presence or absence of BOP for buccal and lingual surfaces of each tooth. PD values were recorded in millimetres from 1 to 10, rounded to the next higher whole number. CEJ-GM distances were recorded similarly, with values of 0 to 10 mm. If the free gingiva was coronal to the CEJ, the CEJ-GM measurement was recorded as 0. Clinical attachment loss (CAL) was calculated by summing the PD and CEJ-GM distance; the CEJ-GM distance was assigned a value of 0 for distal and mesial sites, where this measure was not collected, and these sites were not considered F I G U R E 1 Participation flow chart in measures of CAL. We estimated the validity of PD measurements of the auxiliary nurse midwives relative to the dentist and found that per cent agreement, weighted kappa scores, and intraclass correlation coefficients, with an allowance of PD ± 1 mm, exceeded 99%, 0.7, and 0.9, respectively, indicating an acceptable level of agreement. 20 A case definition of gingivitis was devised by our research team to allow the auxiliary nurse midwives to determine disease status (ie, healthy or at least mild gingivitis) in the participant's home directly after completion of the periodontal examination at the enrolment visit. We selected this approach for logistical reasons, primarily due to the large distances and travel times between participant homes in the study area. We defined healthy participants as those with no Rinse participants were provided with a toothbrush and toothpaste and an initial amount of rinse, sufficient for 2 weeks, and small cup with a line marked at 15 mL. These participants were instructed to rinse twice daily with 15 mL of oral rinse, after brushing their teeth for 1 minute. Rinse safety information was also provided, including storage and how to keep the rinse away from children.
Additional rinse was provided as needed by auxiliary nurse midwives during their weekly adherence visits to participant homes. Control participants received the same oral hygiene information as well as the toothbrush and toothpaste.
Baseline participant characteristics were compared between healthy and diseased groups across rinse assignment through bivariate analyses using cross-tabulations and chi-squared and Fisher's exact tests. We assessed differences in adherence and acceptability using chi-squared tests and linear regression modelling as appropriate. Periodontal measures were analysed using an intention-to-treat approach. We calculated risk ratios for gingivitis (RR) at the end of follow-up and associated 95% confidence internals (CI) using a log-binomial regression models. All statistical analyses were performed in   Table 1).

| RE SULTS
The total volume of rinse used by participants averaged 1921 mL (SD: 851 mL) of a recommended 2520 mL, ranging from 0 mL to 3700 mL (Table 2) keep the rinse away from their children. Rinse adherence was similar between rinse groups, with one exception; four participants in the chlorhexidine group reported sometimes using the rinse before cleaning their teeth.
Nearly all participants in each group reported liking the rinse to some degree when questioned at the end of the trial (Table 3).
Responding about the individual characteristics of the rinse, taste or smell were the two most common aspects of the rinse that participants reported disliking. We found no significant differences in rinse acceptability between rinse groups for any of these questions.  a Complete follow-up is defined as participants followed until the end of the study for whom the final questionnaire and second examination were administered and the data were available for analysis.
b P-value for chi-square test of difference between complete data and incomplete data groups.

| D ISCUSS I ON
We conducted a pilot community-based randomized controlled trial to understand the adherence to and acceptability of three nonalcohol, antiseptic oral rinses among young pregnant women in rural Nepal. Generally, across the three rinses, we observed high adherence to rinse protocol, and participants reported positive opinions of the rinse taste, smell, and other characteristics. These findings suggest that pregnant women might be willing to incorporate an oral rinse into their daily oral hygiene routine. TA B L E 2 Adherence to oral rinse use instructions (n = 125), by group (parentheses contain percentages) Oral rinse use is uncommon in Nepal and other countries in South Asia. A survey of women in this study population that found the prevalence of both dental floss and oral rinse use to be <1%. 18 Another study, conducted in a predominantly urban and semi-urban area of Dharwad District in Karnataka, India, reported a prevalence of oral rinse use of 1% among Indian adults. 19 Although rinse use in this region is uncommon, our findings are supported by a qualitative study conducted by our study team that reported that women in this population would be willing to use an oral rinse during pregnancy if it might have a positive impact on the baby's health; this could also explain the high percentage of women who reported being willing to use an oral rince if they became pregnant again. 24 We additionally considered several secondary outcomes, in-

| CON CLUS ION
Our study demonstrated that adherence to and acceptability of three alcohol-free, antiseptic oral rinses were high among pregnant women in rural Nepal. Among participants with mild gingivitis at baseline, CHX rinse was most effective at reducing signs of disease compared with the control group. Oral rinse should be considered as TA B L E 5 Periodontal measurements among women with gingivitis at baseline and the end of the study, by group (parentheses contain percentages or standard deviation) a Risk ratio of gingivitis at the end of the study for rinse group vs control and 95% CI. a supplement to current oral self-care routines for pregnant women in settings where rinse use is uncommon and access to oral health services is limited.