Purpose: The internal fit and fracture resistance of single-tooth implant-supported all-ceramic crowns after being subjected to different surface treatments. Materials and methods: Thirty specimens of IPS e.max Press crowns were fabricated according to manufacturer instructions on thirty zirconia ceramic abutments. Specimens were distributed to three groups with differing surface treatments: sandblasting with 50μm aluminum oxide; 9% hydrofluoric acid etching; a combination of sandblasting and acid etching. Internal fit was measured using replica technique. Then specimens were silanated and cemented using Variolink II resin cement. Specimens were subjected to 500 cycles between 5ºC and 60ºC for 30 seconds in each dwelling temperature. Fracture resistance was performed using universal testing machine. Results: Mean internal fit of group treated with sandblasting was 310 and its mean fracture resistance was 1005.8, mean internal fit of group treated with 9%hydrofluoric acid was 300.2 and is mean fracture resistance was 811,mean internal fit of group treated with both surface treatments was 266.2 and mean fracture resistance was 1215.7. Conclusion: 1-Fracture resistance is affected by the type of surface treatment performed to lithium disilicate glass ceramics. 2- Internal fit is not affected by the type of surface treatment performed to lithium disilicate glass ceramics.3- The highest fracture resistance obtained by the group treated by sandblasting and acid etching recorded the least internal fit gap thickness.