One aim in pediatric dentistry is to allow our young patients to better experience dental care with comfort so that a relation of confidence is created with their pediatric and later general dental practitioner. If teaching of the RD practice in (under-)graduate training was primarily intended for technical reasons and asepsis of the dental operating field, particularly in endodontics, the clinical experience with this tool has shown an interesting side effect: relaxation and, if the treatment lasts a long time, slumber. This empirical observation has been made for both adults and children. Over the years, the use of the dam has no longer been exclusively indicated for endodontics or adhesive procedures. As students and practitioners acquire more skills in rubber dam use in adults, the step towards its application in the field of pediatric dentistry can easily be made. Our results show that the extra time needed for placing, adapting and removing rubber dam was about 2 minutes. As result of this small extra time, patient and practitioner gain in ergonomics: no more discomfort at the level of cotton rolls and the saliva ejector which reduce space in the operating field, lips, cheek and tongue are spread flexibly unlike manual retraction, no more saliva contaminating the treated tooth. But on top of that, the patient relaxes and sometimes falls asleep. During this research work, the objective was to shed light on this clinical observation by scientific evidence. Observation of behavior and heart rate of patients with or without a dam was chosen in order to have a simple, reproducible and clinically sensible protocol.
Whether in terms of behavior or heart rate, a favorable outcome in the RD group was observed compared to the CR group. This tendency is even more marked in patients observed in conscious sedation. Indeed, if the values recorded at different times in patients treated in the vigil state decrease after the stress peak of local anesthesia (T3), this decrease is even more important in patients in conscious sedation to the point that the patient is more relaxed than entering the dental office. Such a decrease is not observed with CR. The RD brings a state of relaxation to the patient, observable at the behavioral level and the heart rate. These same trends have been observed in other studies.(15, 16)
One of the most comparable studies with ours is that of Ammann et al.: our results point in the same direction, even if two fundamental elements are very different: the operator and the act itself. Ammann et al. mention the possibility of bias linked to the practitioner's preference for providing care under a dam (15). 12 different practitioners participated in our study: this diversity excludes the bias of the single practitioner. Moreover, in this study only fissure sealants were placed, a preventive act that did not require local anesthesia. However, we know that placing the RD clamp can be painful and therefore represents an observation bias in terms of dental anxiety.
Indeed, a RD disadvantage is that it requires local anesthesia (LA) because the placement of the clamp causes significant discomfort that is not present when using CR.(17) In the context of our study, all procedures were performed under LA. In other studies, the effect of the RD has been observed with pits and fissures sealings, an act that does not require local anesthesia. This choice of procedure is a bias in terms of the effect of the RD on anxiety because the placement of the clamp without LA is annoying or even painful. For technical procedures that do not require LA, a recent study has shown the interest of applying topical anesthetics to improve comfort when applying the clamp.(18) Other systems have also been studied, such as Isolite®. (19)
For children, local anesthesia is a source of anxiety. During anesthesia, the score obtained on the Venham scale rises by one or two graduations, even in the most relaxed children. But the interest of this study was to assess the effect of the dam on the anxiety of the young patient. The choice of a treatment with local anesthesia due to the nature of the treatment then made ethical sense.
During the treatment, if noises generated by rotary instruments are the same in both procedures, the suction cannula inconveniences are considerably decreased as soon as the dam is put in place. There was a decrease in the Venham scale or a return to the base level (T0). In the CR group, a persistent stimulus such as water flowing in the mouth or the taste of certain products may contribute to a further rise of stress-related behavior (20).
In our study, anxiety indicators were reduced by the use of the rubber dam during the dental procedures when compared to cotton-roll insolation.
How to explain this reduction of stress in children? "Anxiety is a reaction induced by our primary brain. It decreases by using the dam because it helps to reduce or even eliminate the feeling of rape of his intimacy. The patient no longer feels the intrusion, the tooth is like outside of the mouth "(6).
The dam provides a feeling of protection, as if the care was happening outside the mouth. (15)
The relaxation of the patient illustrated by the results obtained corresponds to what can be observed during clinical practice: the patient has a feeling of dental care being much less invasive: less effort to keep the mouth open during the treatment, less inconvenience by water or by suction in contact with tongue or lingual floor. If the treatment takes a little longer, some patients even tend to fall asleep. No case of falling asleep was not observed in our study because the operative criterion was to be limited to conservative treatments on deciduous molar which were carried out over a fairly short period, less than 20 minutes on average.
The behavior of the child at different times was evaluated in this study. Most children (46/51) were between 0 and 1 throughout the treatment. The difference between the two levels (0 and 1) was hardly noticeable because the stress of the child can only materialize by a tight hand, a worried look, moving feet or other signals. Since these differences in behavior were difficult to discern, the use of heart rate measurement was very relevant. Even if the subgroups of samples were small in terms of the analysis of patients treated under conscious sedation, our study showed a very clear effectiveness of the rubber dam combined with conscious sedation. We could demonstrate a correlation between heart rate and VS, although it was not perfect. Other possible stress indicators were cortisol in saliva.(21) However, heart rate can easily be measured, especially in patients undergoing conscious sedation.
Cardiac frequency (CF) is considered as a very representative parameter of stress. The autonomic nervous system is broken down into two nervous systems, the sympathetic nervous system (exciter) SNS and the parasympathetic nervous system (inhibitor) PNS. In his study, Appelhans showed that in a state of physical or psychological stress, the activity of the SNS becomes dominant. It then produces an excitation and, therefore, an increase in CF. PNS activity dominates during periods of rest or safety and then causes a decrease in CF. (22) So, a physical or psychological stress causes the activation of the excitatory nervous system which increases the CF. In our study, there is a highly significant difference (p = 0.001) in CF that decreases when a dam is used during care.
If this system brings so much benefit, one might wonder why practitioners tend to use it so little. Indeed, currently the RD remains an underused system.(23) The majority of clinical situations where the dental dam is used indicate the value of the mechanical barrier to avoid salivary contamination during bonding or endodontic treatment. (24) In our study, the use of RD has been analyzed as a tool for managing dental anxiety, a tool accessible to any practitioner. If the dental dam requires training for easy installation, master students are quite capable of placing it even despite their experience in very short dental practice. (25) The argument of loss of time during treatment is also often put forward.(2) However, in our study and, whatever the level of expertise of the practitioner, the average duration of treatment is greater than 2 minutes for the RD group, which is explained by the implementation of an additional procedure. The cost of the material is not an argument in Belgium because the nomenclature in our country provides for appropriate pricing and reimbursement.
In conclusion, even if the nature of the care changes, the evolution remains similar, that is to say a decrease in stress during care with rubber dam and an increase when it is not present.
The results obtained in this study show that the use of the rubber dam allows, in addition to all the benefits already mentioned, to reduce the stress in young patients during dental cares.