الفهرس 
( Efficacy of Diode Laser, Experimental Nano Calcium Aluminate Based Material and Biodentine in Furcal Perforation Repair : (Animal Study
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Abstract
This study was designed to Prepare and evaluate the experimental nano bio-ceramic calcium aluminate-based repair material. And to evaluate, the bone healing process and histological changes beneath furcal perforation site after using Diode Laser, Experimental Nano Calcium Aluminate Based Material and Biodentine.
Preparation of the experimental material was done as following, a dry mixture of 1:1 of 99.8% purified Calcium Carbonate (CaCO3) and 99.6% purified Aluminum Oxide (Al2O3) was used to formulate Calcium Aluminate (CA) phase, while Tri Calcium Silicate (C3S) phase was formulated by firing a homogenized mixture of molar ratio 3:1(99.8%) Calcium Carbonate (CaO): 99.6% Quartz (SiO2) with the addition of 0.5% boric acid at 1000 ⁰C for 2 hours. The calcined material was crushed, finely ground and remolded using small amounts of CCl4. The Finley grounded powders of (CA) and (C3S) were investigated by x-ray diffraction and evaluated for cytotoxicity.
The experimental Calcium aluminate / Tri calcium silicate (CA/C3S) material was formulated from the prepared tricalcium silicate (C3S) and calcium aluminate (CA) phases according to the following weight percentages:- 40wt% C3S phase , 40wt% CA phase and 20wt% chemically pure Bismuth Oxide (Bi2O3).
The Experimental material Ca/C3S was tested for cytotoxicity using the (MTTA) technique. Evaluation of the physical and mechanical properties of experimental material (Ca/C3S) was done according to international standards ISO 6876:2012 for setting time, microhardness, solubility and dimension stability. Finally, the Experimental material CA/C3S was tested for calcium ion release using optical Emission Spectrometer (ICP-OES) with synchronous vertical dual view (SVDV).
Nine healthy adult male Mongrel dogs were used in this study, a total of 99 mandibular second, third and fourth premolars, maxillary second and third premolars were selected. Each dog was anesthetized and the selected teeth were isolated with rubber dam, the root canals instrumented using rotary files system, canals were cleaned and obturated. Then creation of a 1.4-mm-diameter perforation was performed in the center of the pulp chamber; the perforations involved the dentin, cementum, periodontal ligament, and 2 mm into alveolar bone.
Teeth was randomly distributed and divided into seven main groups according the used material and the laser application into: -
group I: -Sealed with Biodentine (n=15).
group II - Sealed with Biodentine and 870nm diode laser application (n=15).
group III: - Sealed with temporary filling and 870 nm diode laser application (n=15).
group IV: - Sealed with the experimental CA/ C3S material (n=15).
group V: - Sealed with the experimental CA/ C3S material and 870 nm diode laser application (n=15) .
group VI: - Positive control sealed with MTA(n=15).
group VII: -(Negative control) intact bone with no Furcal perforation, as a reference for normal histological tissue (n=5).
Each of the main six treated groups were subdivided into three subgroups (A, B and C) according the evaluation period: -
Subgroup A: First evaluation period after two weeks (n=5 in each group).
Subgroup B: Second evaluation period after one month (n=5 in each group).
Subgroup C: Third evaluation period after three months (n=5 in each group)
All the materials were prepared acceding to manufacture instructions and applied to the site of perforation .
Irradiation of a diode 870 nm laser was applied at the perforation site before placing the repair materials. After sealing the cavities with final restoration another application for 30 sec on 3 cycles (each cycle 10 sec) perpendicular to buccal bone and the lingual /palatal at the perforation site, the previous step repeated three times per week for two weeks, after the animal was anesthetized.
The animals were sacrificed according to each evaluation period, then teeth with surrounded bone were block sectioned and placed immediately in 10% neutral formalin for tissue decalcification.
For the preparation of histological slides, samples containing the treated teeth fixed by formalin, decalcified by placing in formic acid for 14 days then, 17% EDTA solution for 120 days. Then specimens were then embedded in paraffin wax; sections of each block were cut using a microtome at a setting of 5-micron thickness through the area of the furcal perforation. .Slides were stained with hematoxylin and eosin and examined under light microscopy for qualitative and quantitative analysis.
Cytotoxicity test of the experimental CA/C3S material showed that experimental material has a low cytotoxic effect as the inhibitory concentration inhibit 50% after 24 hr.
The present study showed that the CA/C3S mean setting time is (32.70 min ± 0.75) , the Mean microhardness was (56.50±7.41VHN), The present study showed that the CA/C3S exhibit 0.6 % expansion after 30 days, experimental CA/C3S showed an increase in weight after 7 days.
Comparing the inflammatory score of all the tested groups after three months evaluating period, group (III) (sealed with Cavit and exposed with 870nm diode laser) showed the highest inflammatory score with 60% mild and 40% severe inflammation, Evaluation of induced inflammation in the rest groups showed that the specimens had mild to moderate inflammatory reaction during the first two weeks, then the inflammation decreased by time. With highest records in group (V) showed total absence (60%) or mild (40%) inflammation, and group (IV) with total absence (80%) or mild (20%) inflammation. For group (V) that involved application of 870nm diode laser, it has highest improvement between all the tested groups after three months with no inflammation in 80% of the samples. Bone apposition increased with time to reach the highest score after three months for all the involved groups in the current study except for group (III) (sealed with Cavit and exposed to 870 nm diode laser), it showed no bone apposition. CA/C3S repair material in group (V) stimulates the formation of hard tissue over time, with osteoblastic rimming noted in 80% of samples and heavy osteoid tissue formation noted in 20% at the end of the evaluation periods. CA/C3S cement with the combination of 870nm diode laser in group (V) showed the highest bone apposition score among the tested groups after three months within 60% of the tested samples showing heavy osteoblastic rimming and abundant osteoid tissue formation. This outcome was better than using CA/C3S alone in group (IV).Concerning the periodontal ligament regeneration there was no statistically significant difference between the tested groups. While all the tested groups showed low epithelial tissue invasion at three months interval except for group (III)
For group (IV), there was a significant difference between values measured at different intervals with no cementum formation in all specimens after two weeks, in comparison to cementum deposition in 80% of the cases after three months .
The experimental (CA/ C3S) material within the limits of this study showed low cytotoxicity, good physical and mechanical properties, good impact on decrease the inflammation , high bone repair capacity, periodontal ligament regenerating . The experimental (CA/ C3S) material had a competitive impact on reduce the inflammation , bone healing, cementum deposition to Biodentine and MTA. 870 nm diode laser with the used parameters had a good effect in reduce the inflammation process and increase bone repair when combined with the experimental (CA/ C3S) material
Further studies are needed to improve the physical and mechanical properties of the experimental (CA/ C3S) material ,determine the effect of different diode wave lengths on the material behavior and effect on living tissues.