EXHIBIT 11 - COMPUTATION OF EARNINGS PER SHARE CASTLE DENTAL CENTERS, INC. (IN THOUSANDS, EXCEPT PER SHARE DATA) Three Months Ended Nine Months Ended September 30, September 30, ----------------------- ----------------------- 1996 1997 1996 1997 ------- ------- ------- ------- PRIMARY: Weighted average common shares outstanding ......................... 2,353 2,993 2,194 2,555 Assumed conversion of preferred stock issued within one year of initial public offering .............................. 865 804 865 900 Treasury stock calculation of stock options and warrants issued within one year of initial public offering ....... 28 31 28 31 ------- ------- ------- ------- Total primary shares ............................................... 3,246 3,828 3,087 3,486 ======= ======= ======= ======= Loss before extraordinary item ..................................... $ (283) $ (30) $ (252) $ (111) Extraordinary item ................................................. -- (3,685) -- (3,685) ======= ======= ======= ======= Net loss ........................................................... $ (283) $(3,715) $ (252) $(3,796) ======= ======= ======= ======= Loss per common share: Loss before extraordinary item ................................... $ (0.09) $ (0.01) $ (0.08) $ (0.03) Extraordinary item ............................................... -- (0.96) -- (1.06) ======= ======= ======= ======= Net loss ......................................................... $ (0.09) $ (0.97) $ (0.08) $ (1.09) ======= ======= ======= ======= FULLY DILUTED: Weighted average common shares outstanding ......................... 2,353 2,993 2,194 2,555 Assumed conversion of preferred stock issued within one year of initial public offering .................................. 865 804 865 900 Treasury stock calculation of stock options and warrants issued within one year of initial public offering ................ 28 31 28 31 ------- ------- ------- ------- Total fully diluted shares ......................................... 3,246 3,828 3,087 3,486 ======= ======= ======= ======= Loss before extraordinary item ..................................... $ (283) $ (30) $ (252) $ (111) Extraordinary item ................................................. -- (3,685) -- (3,685) ======= ======= ======= ======= Net loss ........................................................... $ (283) $(3,715) $ (252) $(3,796) ======= ======= ======= ======= Loss per common share: Loss before extraordinary item ................................... $ (0.09) $ (0.01) $ (0.08) $ (0.03) Extraordinary item ............................................... -- (0.96) -- (1.06) ======= ======= ======= ======= Net loss ......................................................... $ (0.09) $ (0.97) $ (0.08) $ (1.09) ======= ======= ======= =======