Fifteen interviews were conducted (13 face-to-face and two by telephone) with 14 participants. One participant was interviewed twice, once prior to, and again after, applying SDF for the first time. No participants contacted refused to participate. Six participants worked within primary care and eight within secondary care. Of the 14 participants, 12 were dentists (nine general dental practitioners, one consultant, one core trainee and one vocational trainee), one dental therapist and one dental nurse. Nine of the14 participants were female. The age of participants ranged from 25 to 61 years with a clinical experience ranging from one to 33 years. Five participants had used SDF before. Most interviews lasted, on average 25 minutes in duration (ranging from 10 to 35 minutes), A few of the interviews were shorter when participants did not have much to discuss i.e. had not had considerable knowledge, or experience with SDF.
DPs’ perceptions about using SDF in practice
The vast majority of those interviewed were aware of SDF and were able to articulate that it can be used for arresting carious lesions in children. A small number also identified that it can be used to treat dentine hypersensitivity or knew that it can be used as a topical fluoride to prevent caries. The black staining of arrested carious lesions was raised by most participants.
“Um, so I know that it’s a method for arresting carious lesions, uh, and quite like with stainless steel crowns, it has a similar challenge, sometimes, to present to the parents that it’s not going to be very aesthetic because it’s going to stain them black”
Four participants reported that they had experience applying SDF before participating in the interviews although one was on extracted teeth only. One DP, a dental therapist, had not applied SDF at the time of their initial interview, however, had a patient booked in for SDF application. A second interview was conducted with this participant to gather feedback and explore their initial thoughts and experience. This made the total number of interviewed DPs with experience of SDF five. It was noted that that these five participants were all employees of Dundee Dental Hospital and School.
DPs’ perceived advantages of SDF
When participants were asked about the advantages of using SDF over other dental treatments, the majority highlighted that minimum cooperation was required; this could potentially be beneficial for children or patients with special needs or dental phobia. One dentist commented that this could result in reduced referrals to secondary care. It was however also highlighted that a degree of cooperation would still be required, given that SDF is prone to staining with anything it comes into contact.
“I think it’ll be good for patients who we’ve got very little cooperation ……... So I think the children who have got developmental issues or erm, a low tolerance for dental treatment will be very good because there’ll be limited time where they’re in the chair”
DP3 (Dental nurse).
The majority of DPs suggested that they believe SDF to be a simple, easy and non-invasive approach for managing carious lesions in children because there is no requirement for local anaesthetic, use of rotary instruments or even excavating carious tissues. One dentist who had used SDF several times commented:
“I think it’s, it’s very easy, it’s very easy to do, it’s um, it doesn’t require us to do anything that a child will, will find particularly traumatic at all… Erm, it’s really no more difficult than putting on fluoride varnish”
DP 2 (Dentist).
Contrary to this, one dentist commented that not requiring an injection was not necessarily a unique advantage of SDF, highlighting other approaches used in children’s dentistry, such as HT.
Participants also suggested that due to being pain free and minimally invasive, SDF may help to acclimatise children to having dental treatment, helping them to be more aware of the dental environment and more accepting of more complex dental procedures in future visits. It may also help build a cooperative non dental-phobic patient through their adult life.
DPs perceived disadvantages and barriers of SDF
The majority of participants were concerned with the aesthetic outcomes of SDF treatment and suggested that the permanent discolouration of arrested carious lesions could potentially be a barrier to parents’ acceptability of its use. SDF can also stain the oral mucosa, skin and the clinic surface. Therefore, DPs highlighted that meticulous attention is required while applying it to avoid any inadvertent spillage or contact. Riva star™ (SDI Limited, Bayswater, Australia), which is the commercial SDF product available in the UK, is a clear solution. One dental therapist who reported having used this particular product reported that they found it inconvenient to use, because it was difficult to notice any accidental spillage before staining occurs.
“Um, I would say the biggest disadvantage with something like silver diamine fluoride would be that get-getting patients to accept it, the fact that it might… they’ve maybe got lesions that are just pale brown or you know, not very highly coloured, when you paint this on it’ll actually turn them black so it’ll look quite unsightly”
DP 8 (Dentist).
Participants believed that the aesthetics associated with SDF application would be the largest barrier from the parent’s and child’s perspective. There was an assumption even from those who had not used SDF before, that parents may not agree to its use. Reasons given for this included, a fear of their child being bullied or a fear of judgment from others, who may think that they are not looking after their child’s teeth.
“Um, I think there are some children where, um, if their teeth go dark chocolate brown they might get picked on at nursery or at school and, um, that certainly -- I have met children where that has been an issue”
Given the additional possibility of inadvertently staining the skin or the gingiva, one dentist suggested that parents may hesitate about choosing SDF unless they fully trusted the DP applying it. One participant mentioned having encountered patients reluctant to receive any fluoride treatment. They believed that SDF would not be an option for these patients:
“There are some parents who believe fluoride is a poison and that is their belief and, um, despite the fact that you and I might think otherwise…”
DP 4 (Dentist).
Another disadvantage highlighted was the unpleasant taste or sensation attributed to SDF. In addition, participants with experience of applying SDF highlighted that it was not easy to access interdental lesions in posterior teeth unless the lesion was fully cavitated. In addition, food packing in that area might obstruct SDF from reaching the whole carious lesion. It was noted that the size of the micro-brush supplied with the SDF kit was not sufficiently small to access fully all interdental lesions in posterior teeth.
A number of participants suggested that the lack of training and information available about using SDF was a barrier to its use in general dental practice. However, this was less of an issue for DPs working within Dundee Dental School who reported that they had received training as to its use.
“I mean, obviously, I work in a teaching hospital so I get exposed to new techniques and things, but people in practice, unless they go on courses to learn how to use it, if they weren’t trained with it, they might be very reluctant to use it not knowing anything about it”
It was suggested that introducing a new fluoride agent into practice may be challenging due to another type of fluoride based preventive material, Fluoride Varnish (FV), having been used in practice for a significant period. In addition, since SDF is licenced for treating dentine hypersensitivity, using it to arrest carious lesions would be deemed “off-label”. Indeed, for this reason, some of those interviewed suggested they would be hesitant to use it, with one DP querying whether there could be legal implications using this “off-label”.
“The off licence to me is more of an issue if you're trying to get it used in general practice because personally, I would feel less comfortable. Doesn’t mean I wouldn’t use it, it just means that I would be a bit more cautious in how I’d approach the children”
Dental Professionals working within NHS primary care highlighted an additional barrier with SDF not currently listed in the Scottish Statement of Dental Remunerations (SDR). As a result, practitioners in Scottish NHS primary care practices would not be able to claim financially for applying this agent.
DPs’ perceived enablers of SDF use
As well as capturing potential barriers to using SDF in practice, factors to enable its use were also explored. It was suggested that the lack of training opportunities available could be addressed with the development of new training courses or Continuous Professional Development events which may in turn encourage use in practice. In addition, educating DPs about the implications of using agents “off-label” would mitigate such concerns.
“Um, so I think for me it was a barrier initially. Um, but then the more I read about it I realised that being used off licence is okay… Um, so I'm very happy to do it now”
It was suggested that in order to facilitate the introduction of SDF to parents, an information sheet, explaining the associated advantages, disadvantages and expected outcomes, with photographs demonstrating arrested carious lesions, could help.
“It would be nice to have something official in place that they could read as well, that’s probably a good consideration”
DP 12 (Dentist).
A few participants suggested that improving the evidence base around the use of SDF for arresting carious lesions in children and restricting or minimising the staining effect could increase implementation. It was also suggested that the introduction of SDF into the SDR would allow NHS primary care practitioners to claim for it, hence removing the financial barrier. Figure (1) summarises the perceived barriers and enablers to using SDF in practice.
DPs’ perceived uses of SDF
The DPs Interviewed for this study believed that SDF would be a useful option for children unable to cooperate or tolerate other treatment approaches. One dentist went on to say that SDF should be limited to uncooperative children but could also be used for adults with dental anxiety or special needs. The majority of participants agreed that SDF would be particularly beneficial in avoiding or delaying the use of General Anaesthesia (GA) and intimated that parents would rather their child had black teeth, whether in the posterior or anterior sextants, if this avoided their child having a GA. A dental therapist who had experience of applying SDF on a three-years old boy’s anterior and posterior carious lesions commented:
“Uh, I didn’t really need to convince her (the child’s mother). She was happy to do it if it’s a possibility of avoiding a general anaesthetic”
DP 5 (Dental therapist).
One dentist identified another potential advantage of SDF was that applying it does not require any complex or advanced equipment, making it particularly useful in developing countries or areas with limited resources. Some DPs also suggested that SDF would be especially valuable where a child has multiple carious lesions, where treating all lesions would normally require several dental appointments. Applying SDF on all carious lesions during one appointment could result in both time and cost savings.
“you’ve often got the situation where a child has got lots of teeth that need treatment, um, so you could quite easily apply SDF on everything, even at one visit. And that would be a quick, cost-effective way of getting it done”
DP 1 (Dentist).
DPs’ views of SDF compared to HT
Some of those interviewed raised points about the similarities between SDF and the HT. The HT has become increasingly popular in children’s dentistry and has been proven to be effective for managing carious lesions in primary teeth (25). This was a theme which emerged from the initial few interviews and as a result the interview topic guide was adapted to specifically explore DPs perceptions of the relative advantages and disadvantages of both SDF and the HT. Some DPs interviewed during this study suggested that SDF would be more comfortable for the child due to the simple application process involved, whereas the HT can be uncomfortable when seating the crowns.
“I mean certainly we do use the Hall crown a, a lot and you know, the Hall Technique and that’s, that’s very effective. But even then there are certain things you’ve got to do with it that maybe are slightly uncomfortable you know, putting the separators, actually seating the crowns, um, and they can be quite difficult, quite challenging if the crown, if it’s difficult to match the crown size to the tooth”
DP 8 (Dentist).
Participants stated that placing the HT requires more cooperation, as fitting the HT crowns has more steps and takes more time than applying SDF.
“Um, however, I guess the downside of the Hall crown is it does need a little bit more cooperation to do I think than SDF, um, because you need to seal it and remove cement and things like that”
DP 9 (Dentist).
It was still felt however, that when it comes to SDF, parents may be more sceptical about its effectiveness due to the lesion being left open, and food might keep packing in the area. The area would require careful tooth cleaning to remove the debris. It was suggested that parents may feel more confident about the use of the HT due to the lesion being covered and because it may not require the same level of follow-up care.
“The only thing about the Hall crown is at least the parent thinks it’s covered so they don’t have to pay so much attention to cleaning they would think in their head, you know, they think oh, it’s covered up whereas they’d be more worried about, “Oh, you’re just putting a paint on and darkening it, you haven’t actually fixed the hole”. So in their head they think why haven’t you fixed the hole?”
DP 11 (Dentist).
DPs’ views regarding parents’/children’s acceptability of SDF
Participants had mixed views about how parents may feel about SDF. Some participants believed parents would be reluctant to have SDF used on their children, due to the discolouration of the teeth, while others thought they would not mind the appearance of SDF treated carious lesions.
“The downside is it does look black so you will get some parents that’ll say, “No, my kid’s not having that done”, I’m sure”
DP 1 (Dentist).
These beliefs were explored further in the interviews, as were the factors that DPs believed may influence parents’ decision-making. Some participants suggested that fathers may be less concerned about the appearance of their child’s teeth after treatment especially if it was simple and pain-free, whereas mothers may be more concerned about the aesthetics. One participant however, disagreed with this viewpoint:
“Um, no, I, I don’t think a mother versus father’s opinion would be different”
DP 7 (Dentist).
Child gender was identified by participants as a potential influence with some participants suggesting that girls are generally more self-conscious than boys. Other participants however, thought that gender would not impact upon the child’s decision-making around SDF. The age of the child at the time of treatment was also identified as potentially influencing parents’ decision-making with some participants suggesting that parents of younger children (six or younger) would be less concerned about discoloration, believing that younger children may not be as self-conscious. It was also perceived that there would be less opposition to SDF being applied to posterior rather than anterior teeth
When exploring children’s acceptability of SDF, DPs suggested that children generally preferred what they consider to be the least invasive treatment and, therefore, may choose SDF, despite the discolouration. One dentist interviewed suggested that while younger children may be less bothered by the staining, they may also be influenced by their parent’s views.
“Yeah, younger kids wouldn’t be as self-conscious. They haven’t got the capacity to determine that, unless of course mummy says it’s horrible-looking then they’re probably not going to be very happy with it either”
Participants believed that older children can be more self-conscious and more accepting of SDF for their posterior teeth, but less so for anterior teeth and may be influenced by their social environment, and therefore may be influenced by other factors, such as the school they attend and the views of their peers.
“I think it, I think it depends on what environment they’re in, so depending on what school they’re at and the type of school that they’re at, ‘cause children can be cruel”
DP 3 (Dental nurse).