Wear of Vita Ambria Only Restoration Compared With IPS Emax Onlay Restoration

The 1ry objective will be to evaluate the amount of wear of onlays restorations made from VITA AMBRIA & IPS e.max Press and their opposing natural teeth. 2. The 2ry objective of the clinical trial will be to evaluate the fractures, retention, contact points, food impaction and radiographic examination of the VITA AMBRIA onlays compared with IPS e.max press onlays as defined by FDI criteria.

A randomized controlled clinical trial, a double-blind (patient and examiner) is conducted by one trained and calibrated operators who perform all restorative procedures. The restorations are evaluated by a blind and calibrated two examiner using the FDI World Dental Federation criteria. A total of 24 patients will be randomly assigned to each group for a total of 48 patients. The randomization sequence will be generated (www.randomlists.com/team-generator) and to ensure the confidentiality of the allocation, this will be used opaque, sealed and numbered envelopes in series. These will be kept with an independent researcher for the moment of inclusion of the subjects. Both groups will receive Onlay preparation . Digital impression by intra oral scanner will be taken, wax pattern for the onlay restoration will be designed and milled using CAD/CAM software. After that, the wax pattern will be invested and final onlay restoration will be constructed from VITA AMBRIA and IPS e.max press ingots according to manufacturing instructions. Primary outcome: The amount of wear will be evaluated according to FDI standard.

The onlays will be constructed from Zirconia reinforced Lithium disilicate (Vita Ambria) glass ceramic system.

onlay restoration will be fabricated from Zirconia reinforced lithium disilicate glass ceramic(vita ambria)

The amount of wear will be defined as follows: Intra oral scanner will be used to scan the surface of the restorations and opposing natural enamel after achieving a complete dry surface by isolation. The recordings that measured at base line and 12 month periods will be superimposed on each other by specific software. Mean values and standard deviations of the amount of wear for all restorations' and opposing enamel's will be statistically analyzed.

contact points and food impaction of the onlay restoration will be evaluated according to FDI standard (Grade 1-5), which has been defined as follows: Grade 1: Normal contact point (floss or 25 µm metal blade of can be inserted but not 50 µm blade). Grade 2: Slightly too strong but no disadvantage: Grade 3: Slightly too weak, no indication of damage to tooth, gingivae or periodontal structures (50 µm metal blade can pass easily but not 100 µm). Grade 4:Too weak (100 µm metal blade can pass) and possible damage (food impaction). Repair possible. Grade 5:Too weak and/or clear damage (food impaction) and/or pain/gingivitis. Requires replacement.

Radiographic examination will be evaluated according to FDI standard (Grade 1-5), which has been defined as follows: Grade 1: No pathology, harmonious transition between restoration and tooth. Grade 2: (2.1) acceptable cement excess present ,(2.2) Positive/negative step present at margin<150 µm. Grade 3: (3.1) Marginal gap < 200 µm, (3.2)Negative steps visible < 250 µm and no adverse effects noticed,(3.3) Poor radiopacity of restorative material. Grade 4: (4.1) Marginal gap >250 µm, (4.2) Cement excess accessible but not removable,(4.3) Negative steps >250µm and repairable. Grade 5:(5.1) Secondary caries, large gaps ,(5.2) Apical pathology ,(5.3) Fracture/loss of restoration or tooth

Inclusion Criteria: The patient is healthy. 18-50 years old. Normal occlusion. Good oral hygiene. Tooth with complete root apex. Tooth with moderate coronal decay. Exclusion Criteria: • Patient Incapable of self-care, mental illness, undergoing radiotherapy, diabetic patient, allergy to one of the materials used, pregnancy, smoker, parafunctional habits, poor oral hygiene, severe periodontitis, tooth need vital pulp therapy or surgical crown lengthening or marginal elevation, tooth with enamel or dentin hypoplasia or hypocalcification, Mallaligned or malformed teeth and adjacent or opposing teeth are missed.

Griffis E, Abd Alraheam I, Boushell L, Donovan T, Fasbinder D, Sulaiman TA. Tooth-cusp preservation with lithium disilicate onlay restorations: A fatigue resistance study. J Esthet Restor Dent. 2022 Apr;34(3):512-518. doi: 10.1111/jerd.12666. Epub 2020 Oct 3.

Lee JH, Myagmar G, Kwon HB, Han JS. A digital method for wear volume loss analysis using a single-scan three-dimensional dataset. J Dent Sci. 2022 Jan;17(1):638-641. doi: 10.1016/j.jds.2021.06.015. Epub 2021 Jul 4.