Effect of Nano Hydroxy Apatite Varnish and Potassium Nitrate Gel on the MIH-affected Permanent Teeth

This randomized clinical trial study aims to investigate the effectiveness of nano-hydroxy apatite crystal varnish, and potassium nitrate gel compared to fluoride varnish, in reducing dentin hypersensitivity, improving a child's oral hygiene, and gingival health, oral health-related quality of life, preventing post-eruptive enamel breakdown, and dental caries, along with economic evaluation.

The research unit of this study will be the MIH-affected permanent tooth, in children aged from six to ten years, from either gender.

Inclusion criteria

Participants related criteria:

• Children aged from six to ten years old.
• Medically free children according to the history taken from their parents.
• Children who are categorized as Class I or II according to the American Society of Anaesthesiologists (ASA).
• Children whom their parents accept to comply with the follow-up visits.
• Children who accept, and their guardians, to participate in the study by signing the informed consent.
• Children with no more than four cavitated primary teeth.

Tooth related criteria:

• The diagnosis of MIH will be done as per the Wurzburg concept, 2023 MIH diagnostic criteria:

The child will be confirmed to have MIH if any of the following characteristics are apparent:

• affected teeth show a clearly defined opacity at the occlusal and buccal surfaces of a tooth,
• defects vary in shape, size, and pattern,
• white, cream-colored, or yellow-brown color deviations are recognizable,
• defects variably vary in size,
• teeth with hypersensitivity are present,
• teeth have an atypical restoration,
• permanent teeth for (suspected) MIH reasons are missing (extractions),
• combinations of the above characteristics are present.

• MIH-affected permanent teeth, suffering from dentin hypersensitivity, (MIH-TNI 3, 4a).
• Positive Schiff Cold Airblasting Sensitivity score (score 1, 2, or 3).

• Exclusion criteria:

Participants related criteria:

• Children with severe behavioral or emotional disabilities.
• Children who received analgesics within the last 24 hours before the procedure.15
• Patients who are using chlorhexidine-based gels or mouthwashes.

Tooth related criteria:

• A tooth with signs and symptoms of irreversible pulpitis.
• A tooth with signs and symptoms of necrotic pulp.
• Sealing therapy or application of desensitizing agent on the MIH teeth within one month before participation in the study.
• Presence of dental caries on the MIH-affected permanent tooth.
• Presence of restoration(s) on MIH-affected permanent tooth.