| Suffolk County | Nassau County | The Hamptons | 
| La Rocco Louis L DDS 2 Joseph Ln Farmingdale NY, 11735 (516) 694-1883 | Labcorp at Hempstead Health - Sheila M Cipolla DDS 80 N Franklin St Hempstead NY, 11550 (516) 481-2042 | ||
| Laboratory Corporation - Henna Hussain DDS 80 N Franklin St Hempstead NY, 11550 (516) 481-2042 | Labowitz Paul DDS 2005 Deer Park Ave Deer Park NY, 11729 (631) 667-4075 | ||
| Lake Grove Dental - Haskel S Schiff DDS 1033 Hawkins Ave Lake Grove NY, 11755 (631) 981-0355 | Lakeville Dental Group 1 Hollow Ln New Hyde Park NY, 11042 (516) 869-3400 | ||
| Lakeville Dental Group - Robert G Devita DDS 1 Hollow Ln New Hyde Park NY, 11042 (516) 869-3400 | Lamberg Steven DDS OFC 140 Main St Northport NY, 11768 (631) 261-6014 | ||
| Lane Kerry J DDS 325 Meeting House Ln Southampton NY, 11968 (631) 283-1543 | Lara Mikhail DDS 953 New York Ave Huntington Station NY, 11746 (631) 423-4000 | ||
| Larios Ernest P DDS 14 Millstream Ln Stony Brook NY, 11790 (631) 689-3800 | Larocca James W DDS 405 Franklin Ave Franklin Square NY, 11010 (516) 437-0804 | ||
| Laser & Cosmetic Dentistry 736 E Park Ave Long Beach NY, 11561 (516) 432-7730 | Laura C Perratto DDS 285 E Main St Smithtown NY, 11787 (631) 382-2495 | ||
| Laura Lee Barinque DDS 50 Harbor Ln Massapequa Park NY, 11762 (516) 541-2612 | Lavorata Carl DDS 1036 W Jericho Tpke Smithtown NY, 11787 (631) 543-4433 | ||
| Lawrence J Richard DDS 101 Ontario St Port Jefferson Station NY, 11776 (631) 331-5200 | Lawrence J Richard DDS 206 Clay Pitts Rd East Northport NY, 11731 (631) 266-5061 | ||
| Lawrence Kessler DDS 5 Hilldale Dr Albertson NY, 11507 (516) 621-2232 | Lazar & Saucer - Martin Lazar DDS 919 Deer Park Ave North Babylon NY, 11703 (631) 669-2830 | ||