It is happy that you did professional scaling as per advice.
The gel is for sensitive gums, after brushing, leave 15 min then apply the gel over the gums and give massage with your fingers. Don't not wash with water, just spit it out . You can use soft brush for brushing. Brush twice daily. Sensitivity, it take 2-3 weeks( try sensodyne paste)to get back to normal.You can use both sides for chewing.
Health Tips
Use mouthwash for 1 week. Avoid hot and cold foods for 1 week.