## 2 Materials and Methods
### Specimens' Preparation  
This study used sixty extracted human premolars that were free of cavities and flaws to conduct an in vitro investigation. These teeth were taken out of the Oral and Maxillofacial Surgery clinic due to periodontal disease. The Dental College's Ethical Committee authorized the infection control procedures for tooth collection. A hand scaler was then used to remove any remaining soft tissue and calculus (Zeffiro, Lascod, Florence, Italy). Next, the extracted teeth were cleaned using a rubber cup filled with a fine pumice water slurry, and then they were examined under a stereomicroscope (Olympus model SZ-PT, Tokyo, Japan) for indications of damage. The teeth were cleaned and disinfected with a 1% Chloramine-T solution for the following three days. The study only comprised teeth that were unrestored, noncarious, and in their entirety. A stereomicroscope (Olympus model SZ-PT, Tokyo, Japan) was used to inspect the teeth. To prevent dehydration, the teeth were then maintained in distilled water and replaced every five days during the study. They were only taken out for the test procedure. The teeth's roots were then buried up to 2 mm beneath the CEJ inside a PVC ring, which is 1.4 \(\times\) 2 cm and cylindrical. It was made of vinyl chloride and auto-polymerizing acrylic resin (Acrostone, Cairo, Egypt). This was performed to stimulate the periodontal \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Material** & **Description** & **Manufacturer** & **Batch** & **Steps of Application** \\ \hline \multirow{4}{*}{Try-In Paste} & \multirow{4}{*}{Glycerin, mineral fillers, and dyes.} & & 1. First the paste was spread on the fitting surface of ceramic restoration. & 1. First the paste was spread on the fitting surface of ceramic restoration. \\  & & & 2. Then, the ceramic was positioned in the correct position. \\ \hline \multirow{4}{*}{Liquid Strip} & \multirow{4}{*}{Glycerin gel.} & \multirow{4}{*}{Schaan, Liechtenstein, Ivoclar Vivadent} & 1. Spread the coating throughout the whole margin prior to light polymerization. & \\  & & & 2. Apply a light cure for 10 s on each part. & \\  & & & 3. Then rinse and dry. & \\ \hline \multirow{4}{*}{Monobond N} & Ethanol, 3-trimethoxysilyl propyl, methacrylate silane, methacrylated phosphoric acid ester, sulfide methacrylate. & & 1. With a brush and a gentle scrubbing motion, apply one layer of the bond. & \\  & & & 2. Let 5 s for a gentle air drying. & \\ \hline \multirow{4}{*}{G-Cem Capsule} & Powder and liquid: initiator, pigment, silica powder, dimethacrylate, phosphoric acid ester, fluoroluminosilicate glass, initiator, trimellitic acid, monomer, water, urethane dimethacrylate, stabilizer 65–70\%wt, 4-methacryloxymethyl. & 1. First the capsule is activated. & 2. Then mix for 10 s using an amalgamator. \\  & & & 3. Spread cement within \\ \hline \multirow{4}{*}{G-Cem Capsule} & Powder and liquid: initiator, pigment, silica powder, dimethacrylate, phosphoric acid ester, fluoroluminosilicate glass, initiator, trimellitic acid, monomer, water, urethane dimethacrylate, stabilizer 65–70\%wt, 4-methacryloxymethyl. & 129921 & 4. Secure the ceramic. \\ \hline \hline \end{tabular}
\end{table} 
Table 2: The luting resin composite system used in this study. ligaments. Each tooth was removed from the cylinder it had been stored in once the acrylic resin had had enough time to dry. To make the impression, polyether impression material (Soft Impregum by 3M ESPE, St. Paul, MN, USA) was injected into the acrylic resin's alveolus. This was accomplished by slicing away the extra polyether material with a scalpel blade, leaving a gap of 0.2 to 0.3 mm, which is nearly equal to the traditional thickness of the periodontal ligament. A high-speed handpiece (Sirona T3, Ballantyne Corporate Pl, Charlotte, NC, USA) was used to prepare the inlay and onlay cavities. Coarse diamond and finishing diamond burs (Inlay Preparation Set 4263; Komet, Lemgo, Germany) and (Onlay prep-set, Intensiv, Viagnello-Lugano, Switzerland) were used to accomplish this.