Dr. Nathaniel I. Grayson, 41, a Silver Spring dentist, has been convicted of failure to file state income tax returns for three years, Maryland Attorney General Stephen H. Sachs said yesterday. It took a Montgomery County jury four minutes to find Grayson guilty of all counts filed against him by the attorney general's Medicaid fraud control unit.

Grayson's tax problems became public last year in the course of an investigation of possible Medicaid fraud during which the attorney general's office issued a grand jury subpoena for Grayson's patient records. When he refused to produce them, he was convicted of contempt of court and sentenced to 89 days in jail.

In the tax case, evidence was presented that Grayson had not filed a Maryland tax return since 1976 and that he owed the state more than $2,695 for the years 1979-81. Sentencing has been set for Aug. 23. AROUND THE REGION Md. Dentist Is Convicted on Tax Charges

Dr. Nathaniel I. Grayson, 41, a Silver Spring dentist, has been convicted of failure to file state income tax returns for three years, Maryland Attorney General Stephen H. Sachs said yesterday. It took a Montgomery County jury four minutes to find Grayson guilty of all counts filed against him by the attorney general's Medicaid fraud control unit.

Grayson's tax problems became public last year in the course of an investigation of possible Medicaid fraud during which the attorney general's office issued a grand jury subpoena for Grayson's patient records. When he refused to produce them, he was convicted of contempt of court and sentenced to 89 days in jail.

In the tax case, evidence was presented that Grayson had not filed a Maryland tax return since 1976 and that he owed the state more than $2,695 for the years 1979-81. Sentencing has been set for Aug. 23.