Mato Sušić

Morphological and Ultrastructural Comparative Analysis of Bone Tissue After Er:YAG Laser and Surgical Drill Osteotomy

OBJECTIVE The purpose of this study was to analyze morphological, chemical, and crystallographic changes of bone tissue after osteotomy performed with an erbium:yttrium-aluminium-garnet (Er:YAG) laser and a low speed pilot drill. MATERIALS AND METHODS Bone blocks were prepared from porcine ribs, and on each block, two tunnel preparations were performed using the Er:YAG laser (pulse energy: 1000 mJ, pulse duration: 300 μs, pulse repetition rate: 20 Hz) or the low-speed surgical pilot drill. The morphological changes of the cortical and the spongious surface of the tunnel preparations were analyzed under the field emission scanning electron microscopy (FE-SEM) at low and high resolution. The distribution and the level of chemical elements in the treated surfaces were evaluated by qualitative and semiquantitative energy dispersive x-ray analysis (SEM-EDX). Diffraction x-ray analysis was used to detect any differences and thermally induced modifications of hydroxyapatite crystals. RESULTS FE-SEM revealed sharp edges of the Er:YAG preparations, with empty intertrabecular spaces and no signs of carbonization. In the drill group, the surface of the preparations was smooth, completely covered with smear layer and microcracks, and with hairy-like irregularities on the edges. SEM-EDX analysis did not reveal any differences in the number of specific chemical elements between the laser and the drill group. There were no thermally induced modifications of hydroxyapatite crystal structure in the bone tissue in either group. CONCLUSIONS The Er:YAG laser ablation did not cause any chemical or crystallographic changes of the bone tissue. Compared with the drill, Er:YAG laser created well-defined edges of the preparations, and cortical bone had no smear layer.

Surgical Treatment of Excessive Gingival Display Using Lip Repositioning Technique and Laser Gingivectomy as an Alternative to Orthognathic Surgery

Excessive gingival display (EGD) is a condition in which an overexposure of the maxillary gingiva (>3 mm) is present during smiling. The proper diagnosis and determination of its etiology are essential for the selection of the right treatment modality. Different techniques have been used in cases of hyperactive upper lip: botulinum toxin injections, lip elongations with rhinoplasties, lip muscle detachments, myotomies, and lip repositions. This report presents a case of a young woman with an EGD larger than 10 mm during smiling caused by altered passive eruption, vertical maxillary excess, and a hyperactive upper lip that was treated with a modified lip repositioning technique and laser gingivectomy because she strongly refused orthognathic surgical treatment. A novel addition to the technique is proposed, a reversible trial accomplished just by applying sutures on the borders of the future split-thickness flap, marked using diode laser, before starting the flap incision.

Odontogenic Sinus Tract to the Neck Skin: A Case Report

We describe a 22‐year‐old woman with neck skin sinus tract that developed as a consequence of dental infection. The patient was treated twice in an inappropriate way with recurrence of the sinus tract. We opted for an extraction of the tooth. This case illustrates the need for cooperative diagnostic referrals between physicians and dentists.

Properties of axially loaded implant-abutment assemblies using digital holographic interferometry analysis.

OBJECTIVE The aim of this study was to (i) obtain the force-related interferometric patterns of loaded dental implant-abutment assemblies differing in diameter and brand using digital holographic interferometry (DHI) and (ii) determine the influence of implant diameter on the extent of load-induced implant deformation by quantifying and comparing the obtained interferometric data. METHODS Experiments included five implant brands (Ankylos, Astra Tech, blueSKY, MIS and Straumann), each represented by a narrow and a wide diameter implant connected to a corresponding abutment. A quasi-Fourier setup with a 25mW helium-neon laser was used for interferometric measurements in the cervical 5mm of the implants. Holograms were recorded in two conditions per measurement: a 10N preloaded and a measuring-force loaded assembly, resulting with an interferogram. This procedure was repeated throughout the whole process of incremental axial loading, from 20N to 120N. Each measurement series was repeated three times for each assembly, with complete dismantling of the implant-loading device in between. Additional software analyses calculated deformation data. Deformations were presented as mean values±standard deviations. Statistical analysis was performed using linear mixed effects modeling in Rs lme4 package. RESULTS Implants exhibited linear deformation patterns. The wide diameter group had lower mean deformation values than the narrow diameter group. The diameter significantly affected the deformation throughout loading sessions. SIGNIFICANCE This study gained in vitro implant performance data, compared the deformations in implant bodies and numerically stated the biomechanical benefits of wider diameter implants.

Plasma rich in growth factors in dentistry

Background Plasma rich in growth factors (PRGF) has wider use in many fields of dentistry due to its endogenous biocompatible regenerative potential i.e., their potential to stimulate and accelerate tissue healing and bone regeneration. Aims This review shows the increasing use of PRGF technology in various fields of dentistry. Methods In the last nine years PubMed has been searched in order to find out published articles upon PRGF in dentistry and 36 papers have been included. Results PRGF technology has many advantages with positive clinical and biological outcomes in tissue healing and bone regeneration. Conclusion In order to determine the most effective therapeutic value for patients, further research is required. Key

Current Concept of Densitometry in Dental Implantology

In the literature densitometric measurements of the alveolar bone are commonly used prior to dental implants placement, as a main part of treatment planning and making the correct indications for dental implant therapy. Different assessment tools for the osseointegration quality evaluation have been proposed in everyday clinical usage. Current method for assessment of outcome of the osseoinegration process of alveolar bone around inserted dental implants is based on densitometric analysis. We have made the modification of conventionally used CADIA (computer assisted densitometric image analysis) and DIGORA software for densitometric measurement. The main task was measurement of bone density around inserted dental implants using the implants as a stepwedge. Main difference between new method and convetional stepwedge-based densitometry is the absence of stepwedge key. Usually, for the stepwedge the aluminium key is used. Digital intraoral periapical radiographs are commonly used for densitometric measurements of the alveolar bone with dental implants. Radiographs were taken following surgery during the wholw follow-up period, depends of certain method. Those RVG images were automatically digitalized and stored in the computer with the processed software DIGORA and adjusted to this research, in measuring bone density around inserted dental implant, not only in certain contours, but also in the precise positions. 12 points with diameter of 1mm on correctly allocated positions on cervical, middle and apical part of newly formated bone, around inserted implant, were measured. The measured densities were obtained automatically due to performed software package, after entering the RVG image. Positions of the 12 points were in advance specified and inserted in the software database, so the measurements on all the implants were every time in the same points. Three of those points served as a correction factors, and they were positioned on different parts of the implant. First correction point was placed in the apical part of the implant, were density of the gray shadows was highest ; second correction point was placed in the middle part of the implant were was already the perforation of the implant for the screw (density of gray shadows have medium intensity), and third correction point was placed on the cervical part of the implant, in the position were the crown screw is attached to the implant (density of gray shadows have minimal intensity) (Figure 1). Correction points served for revision of density changes in measured points which occurred in discontinuity on the x-rays (distortion on x-rays at each of four images in the series of the follow-up, differences in the exposition on the same series of four images that were taken in the follow-up period). Measuring points were positioned: first point was placed 1mm apical of the implant in the middle line, and the rest of 8 points were placed on the precise positions between previously defined screw threads, on each side of the dental implant. All the received densitometry results were processed and afterward used for the evaluation of osseointegration precess after different surgical techniques in dental implantology. In this book chapter this modified method of stepwedge-free densitometry in dental implantology will be clearly explained, making the emphasis on densitometric assessment of some surgical techniques and methods and determination of their clinical values. Assorted clinical cases of each method (maxillary sinus floor elevation techniques, splitting technique of the alveolar ridge, bone grafting procedures and flapless technique of dental implants placement)will be documented. Densitometric comparison between different maxillary sinus floor elevation techniques (lateral approach versus transcrestal approach) will also be shown through this new method. Densitometric assessment of flapless technique and determination of its clinical values in comparison with two-stage dental implant technique through computerized densitometric analysis will also be shown. Improved understanding of this current densitometric analysis may ensure increased bio-safety and predictability during implant placement using different surgical procedures in dental implantology, and may improve clinical decision-making and long-term implant success.