Dentists often experience uncertainty when deciding on the most effective treatment for a particular patient. There are various sources of uncertainty and different strategies for coping with it, such as reducing or accepting it and learning how to make decisions despite feeling uncertain.

The overall objectives of the thesis are to contribute with information that reduces uncertainty regarding the treatment of cariously exposed pulps in young permanent teeth and to improve dental education to ensure that future dental students manage well despite uncertainty.

By means of a systematic review and a model analysis, the thesis evaluates the available evidence and cost-effectiveness of a pulp capping procedure compared to a root canal treatment to reduce the uncertainty regarding the cost-effectiveness of treatments for young permanent teeth with vital pulps exposed by caries.

The thesis also addresses the acceptance of uncertainty. A reflection exercise was developed and tested in a group of dental students. Prompts from an established model were used to stimulate the students to write reflections during the risk assessment of a root-filled tooth. The effect of the reflections on the student’s awareness of and comfort with uncertainty was explored with a repeated questionnaire. The written reflections were analyzed with a qualitative method to explore how dental students reflected on clinical experience in relation to uncertainty.

In the systematic review, the success rate for pulp capping in children and adolescents varied between 64 and 100 percent in the included studies. The model indicated that pulp capping procedures are cost-effective compared to root canal treatment in teeth with pulp exposure due to caries. Fewer teeth were extracted after a pulp capping during the 9 years the patients were followed in the model and the cost for the initial treatment and follow-up treatments during this time period was lower compared to a root canal treatment.

The reflection exercise had an effect on the students’ responses to the questions regarding how certain they believed an experienced colleague would feel, and how certain they felt of their capacity to handle the case. Most students did not state that they felt certain about assessing the risk for exacerbation of apical periodontitis in root-filled teeth but felt certain of their own capacity to handle the case, as well as comfortable with their ability to handle the situation and do their best for the patient.

Three themes about experience and lack of experience were identified in the reflections: “the meaning of clinical experience”, “assumed differences regarding assessment” and “relating to the same risk factors”.

The following conclusions were drawn from the four studies:

For children and adolescents with pulp exposure due to caries, pulp capping procedures are cost-effective compared to root canal treatment, but there is a lack of prospective studies concerning root canal treatment. Moreover, the existing studies on pulp capping procedures are of low quality.

Most final-year dental students participating in a reflection exercise did not feel certain of their risk assessment of root-filled teeth but still felt certain of their capacity to handle the situation, as well as comfortable with their ability to do the best for the patient. The students believed that clinical experience leads to certainty even when the scientific evidence is lacking and experts who meet students have a great responsibility to be transparent with their own uncertainty.

Aims: Reflection on a deeper level is recognized as an important skill to learn for undergraduate students since mastering reflection can be helpful throughout their future careers. The aim with this study was to (i) examine if short structured written reflections could stimulate deep reflection among a group of dental students and (ii) explore specifically how the students reflected on clinical experience in relation to uncertainty when assessing the risk for exacerbation of apical periodontitis in root filled teeth.Methods: Short reflections were written by 52 dental students at Malmö University in 2021. All students first answered some questions associated with the risk for exacerbation of apical periodontitis in a case with a root filled tooth with a diffuse widening of the periodontal ligament space. After this, they were asked to write short reflections following prompts developed specifically to stimulate reflection. For each student, the reflections were analyzed and the level of reflection according to the 4Rs framework (Reporting/responding, Relating, Reasoning, Reconstructing) was assessed. The written content in the reflections were analyzed by a qualitative method, Systematic Text Condensation (STC). Results: Thirteen of the students (25%) reached the deepest level of reflection, Reconstructing. Sixteen students (31%), reached only the most superficial level, Report/respond. Two themes about experience and lack of experience were identified in the reflections: Theme 1 “The meaning of clinical experience” and Theme 2 “Differences and similarities”. The themes were subdivided into nine subgroups and described in more detail the relationship between experience and certainty as perceived by the students.Conclusions: A short reflection exercise stimulated deep reflection in a proportion of, but not all, dental students. The students believed that certainty comes with experience even when there is a lack of scientific evidence.

BACKGROUND: Multivariable prediction models are used in oral health care to identify individuals with an increased likelihood of caries increment. The outcomes of the models should help to manage individualized interventions and to determine the periodicity of service. The objective was to review and critically appraise studies of multivariable prediction models of caries increment.

METHODS: Longitudinal studies that developed or validated prediction models of caries and expressed caries increment as a function of at least three predictors were included. PubMed, Cochrane Library, and Web of Science supplemented with reference lists of included studies were searched. Two reviewers independently extracted data using CHARMS (Critical Appraisal and Data Extraction for Systematic Reviews of Prediction Modelling Studies) and assessed risk of bias and concern regarding applicability using PROBAST (Prediction model Risk Of Bias ASessment Tool). Predictors were analysed and model performance was recalculated as estimated positive (LR +) and negative likelihood ratios (LR -) based on sensitivity and specificity presented in the studies included.

RESULTS: Among the 765 reports identified, 21 studies providing 66 prediction models fulfilled the inclusion criteria. Over 150 candidate predictors were considered, and 31 predictors remained in studies of final developmental models: caries experience, mutans streptococci in saliva, fluoride supplements, and visible dental plaque being the most common predictors. Predictive performances varied, providing LR + and LR - ranges of 0.78-10.3 and 0.0-1.1, respectively. Only four models of coronal caries and one root caries model scored LR + values of at least 5. All studies were assessed as having high risk of bias, generally due to insufficient number of outcomes in relation to candidate predictors and considerable uncertainty regarding predictor thresholds and measurements. Concern regarding applicability was low overall.

CONCLUSIONS: The review calls attention to several methodological deficiencies and the significant heterogeneity observed across the studies ruled out meta-analyses. Flawed or distorted study estimates lead to uncertainty about the prediction, which limits the models' usefulness in clinical decision-making. The modest performance of most models implies that alternative predictors should be considered, such as bacteria with acid tolerant properties.

TRIAL REGISTRATION: PROSPERO CRD#152,467 April 28, 2020.

BackgroundThe nocebo response refers to the phenomenon where non-specific factors, including negative verbal suggestion and treatment expectations, cause adverse events (AE) following a placebo treatment. Non-specific factors are also likely to influence AE occurrence following administration of active pharmacological treatments. ObjectiveThis meta-analysis aimed to estimate the nocebo response in dentistry by assessing the AEs prevalence in placebo- and active arms of randomised controlled trials (RCTs) assessing analgesic treatment following third molar (M3) surgery. MethodsA systematic search was performed in PubMed, Embase, Scopus, Web of Science and the Cochrane Central Register of Controlled Trials. Eligible studies had to report the number of patients experiencing at least one drug-related AE (patients with AE >= 1) separately for the active and placebo arms. The proportion of patients with AE >= 1 and drug-related dropouts were pooled, and risk differences (RDs) between patients in the placebo- and active arm were calculated. ResultsIn 50 independent RCTs of 47 identified articles, the pooled rates of patients with AE >= 1 were 22.8% in the placebo arm and 20.6% in the active arm. The pooled rates of drug-related dropout were 0.24% in the placebo arm and 0.08% in the active arm. There were no significant RDs in patients with AE >= 1 and drug-related dropouts. ConclusionThese results show that patients in the placebo arm reported AEs to the same extent as patients receiving active treatment, suggesting that most AEs in analgesic medication following M3 surgery may be attributed to the nocebo phenomenon.

Evidence for the nocebo effect, a phenomenon characterised by suboptimal treatment efficacy, worsening of symptoms, or the occurrence of adverse events caused by an individual's negative treatment expectations, is growing across a multitude of medical fields. Within dentistry, little attention has been paid to patients' negative expectations, despite a number of studies supporting the influence of related factors, such as dental fear and anxiety, on the severity of peri- and post-operative dental pain. Only recently, a small number of commentaries and letters have emerged, urging dentists to recognise the possible existence of nocebo effects in dentistry and its implications for patient care. The present review summarises essential evidence of the nocebo phenomenon especially in relation to pain and drug administration. Subsequently, an overview of the current evidence of the nocebo phenomenon in the dental field is presented. Finally, based on the general knowledge of the nocebo effect, the review indicates fruitful arrays of research into the nocebo effect in dentistry.