Background: The use of different polymerization methods may result in variation of mechanical properties of composite resin. Polymerization increases the conversion rate of monomers reflecting in improvement of compressive strength. Post-curing methods can be used to increase strength to the composite resin. Purpose: To determine the difference of compressive strength of post cured hybrid composite resin by using three different size of lightbox. Methods: This research was conducted in a true in vitro experiment. Research carried out by making a tube-shaped cylinder hybrid with 3 mm diameter and 6 mm height composite resin samples post cured by using 3 different size of light box, 3 cm x 3 cm x 3 cm (A), 4 cm x 4 cm x 4 cm (B) 6 cm x 6 cm x 6 cm (C), and a non post-curing control. Compressive strength test was then performed using a universal testing machine. Each sample was tested and averaged to obtain values in order to be analyzed statistically using ANOVA and multiple comparison. results: There is an increase in compressive strength of each group, namely group A (172.9460 MPa), B (154.821 MPa), C (154.0789 MPa) and control (123.3550 MPa), and a statistically significant difference (F<0.05). Conclusion: The smaller size of the lightbox is used, the higher the compressive strength of composite resin.

Cyst is an enclosed cavity surrounded by epithelial cells and contains cholesterin. Radicular cysts are formed as aresult of chronic inflammation of malassez epithelium, caused by trauma or untreated pulp necrosis. In this case, a 21years-old man came to Clinic of Conservative Dentistry, Faculty of Dentistry, University of Padjadjaran, in Bandungto get dental endodontic treatment on his maxillary right lateral incisor. Patient experienced trauma after a motorcycleaccident ten years ago. Clinical examination with vitality test, percussion test, palpation test showed no complaints.Radiological examination revealed a radiolucent lesion with a clear boundary around the apical. The disorder wasdiagnosed as a radicular cyst of teeth 12. Conventional endodontic treatment performed using calcium hydroxide as aroot canal medication in eight times visiting. The outcome of the treatment was assessed by clinical and radiographicevaluation that showed a reduction of radicular cyst size. It is concluded that conventional endodontic treatment usingcalcium hydroxide as medications is an adequate root canal treatment, that was accompanied by periodic observationcould heal the radicular cysts

Polimerizatian is the critical stage to determine the quality of composites resin, this involves isolated monomer carbon double bonds being converted to an extended network of single bonds. Physical and mechanical properties of composites are influenced by the level of conversion attained during polymerization. An adequate light intensity and light curing time are important to obtain the degree of polymerization. The objective of this study is to evaluate the difference of the hardness nanocomposites which activated by LED LCU based on the variation of curing times. This study is a true experimental research. The samples were made from nanocomposites material with cylinder form of 4 mm in depth, 6 mm in diameter. This samples divided into 3 groups of curing times. Group, I was cured for 20's curing time as a control due to manufactory recommended; Group II was cured for 30's, and Group III was cured for 40's and the hardness (Rebound hardness tester) was determined using Rebound scale (RS) and converted by Mohs scale (MS). There was a very significant level of hardness rate from each group using ANOVA test. The result of the study concludes that there were the differences on the nanocomposites hardness level cured under different curing times 20, 30 and 40 sec. The longer of curing times, the higher level of hardness.

Total etch adhesive system has been widely used in teeth conservation area as an adhesive agent before implicating composite resin restoration agent. The aim of this research is to prove the difference of tensile bond strength between total etch (Single Bond) and self etch adhesive system (Adper prompt L-Pop) on dentin surface in vitro. The extracted and non carries maxillary premolar teeth were used in this research and were divided into 2 groups. The first group comprised 15 specimen teeth etched in phosphoric acid and was applicated with the Single Bond adhesive agent. The second group comprised 15 specimen teeth, applicated with the Adper Prompt-L-Pop. The composite resin (Z 350, 3M) was applied incrementally and each of the layers was rayed for 20 seconds. The specimens were stored in physiologic solution before they were tested. Tensile bond strength was measured by LRX Plus Lloyd Instrument, with 1 N load and 1 mm/minute speed, and the measurement result was in Mpa unit. The result was evaluated statistically by the Student t-test with α = 0.05. Single Bond (the 5 th generation) showed a better bond strength compared to the Adper Prompt-L-Pop (the 6 th generation).

Resin based luting cement application generally requires pre treatment procedure such as, etching and adhesive application prior to cementation. This multi step application technique might compromise bonding alternative effectiveness and is time consuming. An alternative for multi step resin cement is the self adhesive resin cement that combines the use of etch, adhesive and cement in one single application. The objective of this study was to compare the bonding effectiveness of the multi step resin cement and the self adhesive resin cement using tensile bond strength method towards indirect composite block dentin surface. This study was a true experimental research conducted by in vitro method on 30 flat dentin surfaces created from extracted lower premolars samples. Samples were divided into two groups, each 15 samples for multi step and self adhesive resin cements. An indirect composite block (2x2x10 mm) was then cemented to each dentin surface using multi step resin cement (Rely X ARC, 3M ESPE) or self adhesive resin cement (Rely X Unicem, 3M ESPE) according to manufacture's instruction. Samples were storage for 24 hours in saline water and tensile bond strength of each samples were tested using the LRX Plus Lyod Instrument at 1 mm/minute speed. The result of the study concluded that the tensile bond strength of multi step resin cement towards indirect composite restoration and dentin surface was significantly higher than the self adhesive resin cement.