At present, dentistry aims for conservative treatments with the goal of maintaining as much tooth structure as possible. Dental caries remains the most prevalent chronic disease worldwide; these lesions can progress rapidly and reach deeper areas of the tooth. The carious lesion is considered deep when it goes through the main tissues of the tooth, and it can affect the pulp tissue, where the nerve and nutrients of the tooth are located. There are many treatment options for deep carious lesions and they vary by the clinical scenario. Vital pulp therapy has become a fairly predictable alternative treatment to pulpectomy (root canal therapy). The goal of vital pulp capping therapies is to keep the pulp of the teeth vital to prevent further interventions such as root canal treatments and complex restorative work. There are two main clinical scenarios when treating these lesions, depending on the remaining dentin thickness between the carious lesion and the pulp: vital direct and indirect pulp capping. Direct and indirect vital pulp therapies are routinely performed using different clinical protocols. The clinical protocols are selected based on the remaining dentin (between the tooth preparation and pulp) and the restorative materials. There are few studies that evaluate pulp capping method in adult teeth (permanent dentition); many studies have investigated baby teeth (deciduous teeth). Routine therapies include the using of adhesive restorations with and without an intermediate layer of restorative material. Calcium hydroxide based cements have been used for pulp capping as an intermediate layer of restorative material. More recently a new intermediate layer of restorative material composed of resin-modified calcium silicate has been indicated for use on direct and indirect pulp capping. The aims of this study are to compare, over a period of 12 months, the post-operative sensitivity and pulp vitality of three indirect pulp capping protocols and two direct pulp capping protocol in vital teeth. This study will provide the necessary evidence to allow clinicians to select the best restorative protocol when treating deep carious lesions where indirect and direct pulp capping protocol are needed.

This randomized, controlled, double-blind, prospective study compares over a period of 12 months, the post-operative sensitivity and pulp vitality of three indirect pulp capping protocols (TheraCal, Bisco; Dycal, Caulk, and no liner). The study was approved by the University of Illinois internal review board (Protocol # 2014-1163). Potential subjects will be screened by one of 3 calibrated investigators through a brief interview and intraoral examination. The screening process includes a medical and dental history, demographics, current/concomitant medication, oral soft and hard tissue examination, 2 radiographs: one periapical and one bitewing, and a review of all inclusion and exclusion criteria. The inclusion criteria consist of adults in good general health between 18 and 64 years of age; with primary active carious lesions deep into the dentin (75% or more of carious dentin) of permanent teeth; absence of clinical symptoms of irreversible pulpitis (spontaneous pain and lingering pain for more than 10 seconds after cold stimulus), and absence of periapical pathology, sinus tract, swelling or abnormal mobility. The outcomes measures are pain using visual analog pain scale (pain assessment form) and success rate (pulp vitality based on percussion, palpation, cold test, radiographic findings), collected at the screening visit, intervention day, 24 hours, 7 days, 3 months, 6 months, and 12 months follow-up visits,

Inclusion Criteria:

Clinical inclusion criteria:

• Adults in good general health between 18 and 64 years of age;
• Active carious lesions deep into dentin (75% or more of dentin) involving occlusal/incisal and/or proximal surfaces of permanent teeth;
• Absence of clinical symptoms of irreversible pulpitis (spontaneous pain);
• Absence of periapical pathology, sinus tract, swelling or abnormal mobility;
• Restorable teeth.

Radiographic inclusion criteria:

• Extension of carious lesion close to potential exposure upon excavation (within the D3 region - lesion extending 2/3 within dentin); with the presence of a well-defined radiodense zone between the lesion and the pulp;
• Absence of periapical radiolucency;
• Absence of thickening of the periodontal ligament,
• Absence of resorptive defects.

Exclusion Criteria:

• Non restorable teeth;
• Teeth with:
• Recent trauma (within 6 months);
• Calcified root canals;
• Periapical radiolucency;
• Patients experiencing spontaneous moderate to severe pain;
• Patients that are pregnant or planning to become pregnant in the next year.
• Patients taking analgesics, anti-inflammatory, or antidepressant medications;
• Patients with orthodontic treatment;
• Newly erupted teeth.