Depending how old the child is the bitewing could also be D0272

D0145-New patient under 3
D0150-New patient 4 and older
D0120-Established patient
D1120-Child prophy through 12
D1110-Adult prophy 13 and older
D0272-Two bitewings
D0274-Four Bitewings
D0330-Panorex
D1206-Topical Fluoride Varnish
D1208-Topical Fluoride-excluding varnish

Depending on the age of your child, how many Bitewings taken, and what type of fluoride is used, depends on which codes you would you. The codes above are codes you can bill out for.
You can also tract counseling/diagnostic documentation with codes, for example:

Caries Risk Assessment
D0601-Low risk
D0602-Moderate risk
D0603-High risk

Preventive tracking
D1301-Immunizaiton counseling
D1310-Nutritional counseling
D1320-Tabacco counseling
D1321-Adverse oral, behavior, and substance counseling
D1330-Oral hygiene instructions

These are mainly used for tracking and documenting on a claim level. It make it easier to run reports. While you can add fees to them, most insurances will not pay, and patients do not appreciate it.

D1120 Child Prophy
D0120 Periodic Exam
D0274 Two-Bitewings
D1206 Fluoride