Key messages

• No studies were found that looked at the need of root canal treatment.
• Two-step caries removal (stepwise) could decrease the risk of pulp exposure, the risk of signs and symptoms of pulp disease and the risk of restoration failure in teeth with deep caries (low certainty of evidence).

What is the evidence.
See evidence matrix in Epistemonikos later

We found three systematic reviews [2], [7], [17], which included five primary studies overall, reported in five references [8], [9], [10], [11], [12]. Four correspond to randomized trials [8], [10], [11], [12].

The table and summary are based on the randomized trials, as the observational studies did not increase the level of certainty of the evidence nor added any additional relevant information.

What types of patients were included*

Of the four trials, one included only children (five to 10 years) [12] and three included children and adolescents (four to 18 years) [8], [10], [11]. One included only primary molars [12], two trials included only permanent teeth [8], [11] and only one trial include both dentitions [10]. 

Regarding the extent of caries, three trials describe that they included deep carious lesions [8], [11], [12]. One trial describes that they were carious lesions with probable pulp exposure during treatment [10].  

Finally, all the trials excluded patients with irreversible pulp symptoms and / or apical lesions prior to inclusion [8], [10], [11], [12].

What types of interventions were included*

All trials compared stepwise (two-step) removal of dentin caries compared to non-selective removal. 

Removal using a stepwise technique (two-steps), consisted of excavating the carious dentin in the first stage until leaving a thin layer of soft dentin tissue on the floor of the cavity and making a provisional restoration. In a second stage, the provisional restoration was removed and a permanent restoration was placed [4], [5]. The period prior to completion of the final restoration ranged from four to eight weeks in one trial [12], and in the other three trials from eight to 24 weeks [8], [10], [11]. 

Complete removal was described in all trials as excavation until hard dentin was found or pulp exposure occurred [8], [10], [11], [12]. 

For provisional restoration, two trials used calcium hydroxide and zinc oxide eugenol [8], [10], one trial used calcium hydroxide and orthophosphate cement [12]; and one trial used calcium hydroxide and self-curing glass ionomer [11]. 

For the permanent restoration, one of the trials used amalgam [12], while two trials used calcium hydroxide as base and resin or amalgam [8], [11]; one of them also included zinc oxide and glass ionomer cement. [8]. Finally, a trial used modified glass ionomer resin as base and compomer for primary teeth and resin for permanent teeth [10]. 

None of the reviews included information on the instruments used or the depth of excavation.

What types of outcomes 
were measured

To whom this evidence does and does not apply

• The results of this summary are applicable to people with deep tooth decay in temporary and/or permanent teeth, especially children and young adults.

• The outcomes selected are those considered critical for decision-making according to the opinion of the authors of this summary, which coincide in general with those presented in the systematic reviews identified.
• The “pulp exposure” outcome was included in the summary of findings table because it is a relevant outcome for clinical experts, even when it is an intermediate outcome for the need of root canal treatment.
• The outcome need for endodontic treatment is critical for health decision-making as it involves performing an additional procedure that is more complex and costly for the patient, but this outcome was not reported. 
• It is necessary to establish main outcomes (core set outcomes) for clinical trials on caries management, including long-term effectiveness measures (survival of restoration) and patient values and preferences.

• The evidence presented in this summary shows a possible benefit for stepwise removal in the risk of pulp exposure, risk of signs and symptoms of pulp disease and restoration failure.
• The length of follow-up of the included studies (six to 16 months) makes it difficult to measure the long-term adverse effects of both interventions. 
• It is not possible to determine the balance between benefits and risks between stepwise and complete removal because the certainty of evidence was low or very low for reported outcomes.

• None of the included studies performed a cost-effectiveness analysis of stepwise removal and complete removal techniques.
• There is evidence that stepwise removal would increase operative and total cost of dental treatment, since it requires two or more sessions [3]

• Most patients would prefer complete caries removal over selective partial or two-step removal. This preference is marked by the quality of the treatment, the sociodemographic characteristics, the personality of the patient, and previous dental experiences [13].
• There is evidence that almost half of dentists prefer the use of conventional techniques such as non-selective removal, for the treatment of deep dental caries. However, in recent years this preference has decreased, increasing the preference for conservative removal techniques [3].
• A limitation for the practice of the two-step technique (stepwise) could be patient dropout. Once the pains or dental sensitivity are resolved, patients often do not return to the dental office.
• Taking into account the results of this summary, patients and dentists are expected to be in favor of stepwise caries removal, due to the importance of the expected benefits of this technique in relation to its possible harms.

Differences between this summary and other sources

• The conclusions of this summary are consistent with all included systematic reviews [2], [7], [17] which consider that there is a benefit of stepwise removal on the outcomes of pulp exposure, restoration failure and signs of pulp pathology. However, there is uncertainty given that the level of confidence of the evidence is low.
• From clinical practice guidelines consulted [14], [15], [16], only the Ministry of Health of Chile guideline [16] mentions the two-step technique (stepwise) for the management of caries lesions in permanent teeth, and temporary vital and asymptomatic caries lesions that require operative treatment. It is recommended to perform partial caries removal therapies in one or two stages.

• There is a high probability that future research will change the conclusions of this summary due to the uncertainty in the existing evidence.
• We have not identified ongoing randomized trials in Clinical Trials on this technique.
• Systematic reviews that include new evidence could shed new light on this question. However, we did not identify any ongoing study in International prospective register of systematic reviews [PROSPERO] of the National Institute for Health Research.