A Comparative Analysis Regarding the Osseointegration of Immediate Loaded Implants Using Two Different Implant Site Preparations: Erbium:Yttrium-Aluminum-Garnet Laser Versus Surgical Conventional Way-An In Vivo and Histological Animal Study.

Objective: The aim of the study is to evaluate the possibility of preparing the implant site using the erbium:yttrium-aluminum-garnet (Er:YAG) laser scanner prototype and to reduce and/or eliminate time between primary (mechanical) stability and secondary (biological) stability, looking to the immediate occlusal loading in a single implant. Background: A prerequisite for successful osseointegration is the establishment of direct bone-to-implant contact without interposition of nonbone or connective tissue. In recent years, the use of laser radiation was presented as an alternative/adjunctive treatment for bone tissue ablation due to vaporization of the tissues in the absence of a smear layer. Methods: The experimental protocol included six minipigs, which underwent tooth extraction, followed (after 2 months) by implant bed preparation in two methods: using a conventional bur kit and using an Er:YAG laser scanner (X runner) protocol. Four implants were placed in positions 34, 37, 44, and 47 on each animal. The animals underwent the second surgical procedure for bone sample collection (including the implant) before their sacrifice at 45-60-90-120 days. The newly formed bone was evaluated on the bone samples using histological examination and quantitative evaluations of different histological parameters based on microscopical analysis. Results: The results that we obtained allow some interesting comparison in terms of different bone composition, depending on the method of implant site preparation and on healing periods. Moreover, it was possible to compare the bone composition, at different time stages, of implant sites prepared in the same way. Conclusions: Our research allowed us to demonstrate that the use of Er:YAG laser compared with traditional drill leads to the presence of a greater share of lamellar bone and a lower necrotic share in the implant site. We also showed the possibility of applying immediate occlusal loading on an in vivo animal model.

Effect of the laser beam on implant site preparation: a preliminary pilot study.

The aim of this preliminary study is to histologically evaluate the effects of erbium-doped yttrium aluminum garnet (Er:YAG) laser on soft and hard tissues during implant bed preparation, in comparison with bur and cutter in order to observe the following aspects: (i) the shape of the cavity, (ii) the presence of debris, and (iii) structural modification of the cell architecture. Bone temperature changes during the preparation of the implant bed were also measured in order to evaluate thermal damage on soft and hard tissues. Er:YAG laser, Fotona X-Runner scanner and circular cutter of 5 mm diameter were compared using an in vitro model. Implant bed preparations were performed in bovine rib bone (hard tissue) and tongue muscle (soft tissue) tissues. Results of the study show that in all bur samples were present more debris and more blood cells than in laser samples, which, according to the rules of healing processes, can be a negative factor for the osseointegration process. Regarding the thermal effects on soft tissue, they were present when using MAX mode, but absent when using quantum square pulse (QSP) mode. A preliminary conclusion emphasizes the use of laser to prepare the implant site without debris formation. Nowadays, is not still present a laser device that can overtake the technical limitations of the laser scanner (i.e., deepness control and scanner movement during the preparation of the holes, etc.).

Er:YAG laser cavity preparation and composite resin bonding with a single-component adhesive system: relationship between shear bond strength and microleakage.

BACKGROUND AND OBJECTIVES: The purpose of this study was to assess the performances of a single-component adhesive system when an Er:YAG laser was used to prepare cavities. STUDY DESIGN/MATERIALS AND METHODS: Shear bond strength tests were performed on composite rods bonded with a single-component adhesive system to dentin surfaces prepared using either bur+acid, Er:YAG laser (fluence = 44 J/cm2), or Er:YAG laser+acid. Class V cavities were prepared differently according to the molar surface: buccal surfaces were prepared using a diamond bur, and lingual surfaces using the Er:YAG laser. In group 1, cavity walls were not acid treated after Er:YAG laser preparation. In group 2, only the enamel walls were acid treated. In group 3, all the enamel and dentin walls were acid treated. Microleakage was assessed using a methylene blue dye penetration method. RESULTS: Bond strength values did not differ significantly between the three groups (P = 0.162). Better marginal adaptation was obtained between the composite resin and cavity walls when Er:YAG laser preparation was followed by a total acid etching (P = 0.008). CONCLUSIONS: Our results supported the use of single-component adhesive systems in cavities prepared using Er:YAG laser. The step of acid etching must be maintained for the whole cavity walls in regard of the microleakage values.