Dino Re

Effect of different bur grinding on the bond strength of self-etching adhesives

This study compared the microtensile bond strength (MTBS) of three all-in-one adhesive systems and a two-step system using two types of burs to prepare the dentin surfaces. Flat coronal surfaces of 24 extracted human molars were produced using either regular-grit or superfine-grit diamond burs. Resin composite was then bonded to equal numbers of these surfaces using one of the four adhesives: Clearfil SE Bond (CSE), G-Bond (GB), SSB-200 (SSB) or Prompt L-Pop (PLP). After storage for 24 hours in 37 degrees C distilled water, the bonded teeth were sectioned into slices (0.7-mm thick) perpendicular to the bonded surface. The specimens were then subjected to microtensile testing and the bond strengths were calculated at failure. Bond strength data were analyzed by two-way ANOVA and the GamesHowell test for interaction between adhesive and type of cut dentin. The fractured surfaces were observed by SEM to determine the failure mode. In addition, to observe the effect of conditioning, equal numbers of the two bur-cut dentin surfaces of eight additional teeth were conditioned with the adhesives and observed by SEM. Based on the results, when CSE and SSB were bonded to dentin cut with a regular-grit diamond bur, the MTBS values were significantly lower than that of superfine bur-cut dentin; whereas, GB and PLP showed no significant differences in MTBS between the two differently cut surfaces. SEM observation of the fractured surfaces revealed a mixed mode (adhesive in some areas and cohesive in others in the same sample) of failure in all specimens except PLP, which showed cohesive failure within the adhesive for both types of bur preparation. Generally, SEMs of the conditioned surfaces using both types of burs showed partial removal of the smear layer for CSE, minimal for GB and SSB and complete removal for PLP. In conclusion, when cutting dentin, selecting the proper bur type is important for improving the bond strength of some self-etching adhesive systems.

Maxillary Sinus Septa and Anatomic Correlation With the Schneiderian Membrane.

AbstractAim of this investigation is to evaluate prevalence, localization, and height of 114 maxillary sinus septa by using cone-beam computed tomography scans. The thickness of the mucosa has been measured together with the variations of the membrane in relation to those septa.A total of 228 maxillary sinuses have been considered. Septa were identified using “panorex” reconstructions and axial scans of cone-beam computed tomography using the software “eXamVision.” The thickness of the mucosa has been evaluated in the paraxial scans and related to those septa where they were present.In the current study, the prevalence of sinus septa is 38.1%. Significant difference can be found in the height of primary and secondary septa. The mean height of primary septa was 5.5 mm (±1.19) and of secondary septa 3.4 mm (±1.6). Anterior and medium septa resulted significantly higher than posterior septa (P = 0.003). The medium thickness of the mucosa was 0.85 mm (±0.58), whereas close to the septa it turned out to be 1.8 mm (±1.87). The difference is statistically relevant (P = 0.003). There is no statistically significant proportional relation between dimensions of septa and thickness of mucosa (P = 0.53).Underwood septa are frequent anatomic variations of the maxillary sinus. Their presence may result in a thickening of the sinus membrane. The systematic study of radiographic anatomy of maxillary sinus is necessary before the sinus lift surgery planning.

Zirconia implants in esthetic areas: 4-year follow-up evaluation study

Objectives. The aim is to evaluate the survival and success rates, as well as the marginal bone loss (MBL) and periodontal indexes of zirconia implants positioned in the esthetic jaw areas. Materials and Method. 13 patients were selected and 20 one-piece zirconia implants were used for the rehabilitation of single tooth or partially edentulous ridge in the esthetic jaw areas. Six months after surgery and then once a year, a clinical-radiographic evaluation was performed in order to estimate peri-implant tissue health and marginal bone loss. Results. The survival and success rates were 100%. The average marginal bone loss from baseline to 48 months after surgery was +2.1 mm. Four years after surgery, the median and the mode for visible Plaque Index and Bleeding On Probing resulted 1 whereas Probing Pocket Depth amounted to 3 mm (SD = ±0.49 mm). Conclusion. One-piece zirconia dental implants are characterized by high biocompatibility, low plaque adhesion, and absence of microgap that can be related to the clinical success of these implants even in the esthetic areas.

La responsabilità professionale in odontoiatria: analisi di una casistica interdipartimentale

Riasunto Obiettivi L’incremento degli addebiti di responsabilita professionale in ambito sanitario, unitamente alla diffusione di dati espressivi di una differente distribuzione percentuale dei settori odontoiatrici coinvolti nel contenzioso, ha indotto gli autori a condurre un’analisi conoscitiva del fenomeno attraverso lo studio di una casistica interdipartimentale di accertata responsabilita professionale odontoiatrica in ambito civilistico. Materiali e metodi E stata condotta un’analisi descrittiva di tipo poliparametrico su un campione costituito da 436 casi di errata condotta odontoiatrica accertata, promossi da soggetti di eta compresa tra 14 e 70 anni. Risultati Il settore odontoiatrico in cui e piu frequentemente ravvisato un errore tecnico-deontologico e quello protesico e implantoprotesico, seguito da quelli endodontico- conservativo e ortognatodontico. Nella maggioranza dei casi si e accertata la carenza della documentazione sanitaria descrittiva dello stato anteriore, in assenza di un modulo di consenso informato al trattamento odontoiatrico. Il danno ha riguardato piu frequentemente strutture dentarie, concretizzandosi in un danno permanente alla persona ≤ 4% in oltre due terzi dei casi, con un importo del danno emergente quasi sempre (97%) Conclusioni Gli autori propongono un decalogo comportamentale al fine di ridurre i possibili addebiti di responsabilita professionale o, comunque, utile a documentare la corretta condotta tecnico- deontologica.

Inlay-retained fixed dental prosthesis: a clinical option using monolithic zirconia.

Different indirect restorations to replace a single missing tooth in the posterior region are available in dentistry: traditional full-coverage fixed dental prostheses (FDPs), implant-supported crowns (ISC), and inlay-retained FDPs (IRFDP). Resin bonded FDPs represent a minimally invasive procedure; preexisting fillings can minimize tooth structure removal and give retention to the IRFDP, transforming it into an ultraconservative option. New high strength zirconia ceramics, with their stiffness and high mechanical properties, could be considered a right choice for an IRFDP rehabilitation. The case report presented describes an IRFDP treatment using a CAD/CAM monolithic zirconia IRFDP; clinical and laboratory steps are illustrated, according to the most recent scientific protocols. Adhesive procedures are focused on the Y-TZP and tooth substrate conditioning methods. Nice esthetic and functional integration of indirect restoration at two-year follow-up confirmed the success of this conservative approach.

Effect of different dental articulating papers on SEMG activity during maximum clenching.

This study evaluated the influence of two different occlusal indicators (articulating papers of 40μm and 200μm) on muscular activity of the temporalis anterior (TA) and superficial masseter (MS) during maximum voluntary clenches (MVC), using surface electromyography (SEMG). It was hypothesized that an articulating paper positioned between dental arches during MVC elicits a different muscular activity compared with the occlusion on natural dentition (without the occlusal indicator). 30 healthy adult subjects with a complete, natural dentition were recruited; SEMG activity was recorded in the following experimental conditions: MVC with cotton rolls for standardization purposes; MVC on natural dentition; MVC onto the 40μm or 200μm paper indicator positioned on right or left side of the dental arch. Percentage Overlapping Coefficient (POC; separate values obtained for TA and MS), antero-posterior coefficient (APC) and total muscle activities (IMP) were the analyzed SEMG parameters. The use of an occlusal indicator statistically changed POC_TA, POC_MS and IMP median values (p<0.05). Both 40μm and 200μm occlusal papers did not significantly affect APC values (P=0.86). A pronounced asymmetric muscular activity has been recorded with the introduction of an interocclusal media. All indices of muscular activity did not differ between sexes (Kruskal Wallis test, P>0.05). In conclusion, the examined articulating papers affected two specific SEMG parameters (POC and IMP); the recorded muscular activity with the occlusal indicator varied regardless left or right side positioning, and independently from tested paper thicknesses.

Esthetic Rehabilitation of a Severely Compromised Anterior Area: Combined Periodontal and Restorative Approach

The complete oral rehabilitation of patients demanding a beautiful and attractive smile involves a multidisciplinary approach that includes the change of both the morphological aspect of the teeth and the architecture of gum tissues. This clinical report describes a successful interdisciplinary approach for the treatment of an esthetically compromised dentition. In a first phase, the periodontal plastic surgery was performed for root coverage and, in particular, it was decided for the execution of a coronally advanced flap for the treatment of multiple recession defects. Once complete healing of soft tissues was obtained, six lithium disilicate veneers were placed over the anterior maxillary teeth. Lithium disilicate is a glass-based ceramic which presents excellent aesthetics and allows the passage of light without creating unnatural reflections. This feature has made it possible to recreate a natural aspect of teeth that in combination with the harmonic architecture of soft tissue has permitted obtaining a beautiful and pleasant smile.

Treatment of the atrophic upper jaw: rehabilitation of two complex cases.

In reconstructive surgery, the fresh frozen homologous bone (FFB) represents a valid alternative to the autologous bone, because FFB allows bone regeneration thanks to its osteoinductive and osteoconductive properties. The purpose of this work is to describe the surgical-implant-prosthetic treatment of two complex cases using FFB. In particular, fresh frozen homologous bone grafts were used to correct the severe atrophy of the maxilla, and, then, once the graft integration was obtained, implant therapy was performed and implants placed in native bone were immediately loaded.

Odontogenic Keratocyst Mimicking Paradental Cyst

Objective. The aim of this paper is to present an uncommon clinical and radiographic aspect of odontogenic keratocyst (OKC) mimicking paradental cyst. Methods. A 32-year-old female patient showed a well-delimited radiolucent lesion connected with the root of the left third molar with close anatomical relationship with the mandibular canal. The clinical, radiographic, and anamnestic features lead us to diagnose a paradental cyst that was treated by enucleation after extraction of the partially impacted tooth. Results. Histological analysis showed typical histological features of PKC such as the presence of a lining of stratified squamous epithelium with a well-defined basal layer of palisading columnar of cuboidal cells. Conclusion. Initial X-ray analysis and the position of the lesion related to the third mandibular tooth caused us to mistakenly diagnose a paradental cyst. We were only able to identify the cyst as an PKC rather than a paradental cyst after histological analysis.

Digital Device in Postextraction Implantology: A Clinical Case Presentation

Aim. The aim of this work is to describe a case of immediate implant placement after extraction of the upper right first premolar, with the use of CAD/CAM technology, which allows an early digital impression of the implant site with an intraoral scanner (MHT 3D Progress, Verona, Italy). Case Report. A 46-year-old female was referred with a disorder caused by continuous debonding of the prosthetic crown on the upper right first premolar. Clinically, there were no signs, and the evaluation of the periapical radiograph showed a fracture of the root, with a mesial well-defined lesion of the hard tissue of the upper right first premolar, as the radiolucent area affected the root surface of the tooth. It was decided, in accordance with the patient, that the tooth would be extracted and the implant (Primer, Edierre implant system, Genoa, Italy) with diameter of 4.2 mm and length of 13 mm would be inserted. After the insertion of the implant, it was screwed to the scan abutment, and a scan was taken using an intraoral scanner (MHT 3D Progress, Verona, Italy). The scanned images were processed with CAD/CAM software (Exocad DentalCAD, Darmstadt, Germany) and the temporary crown was digitally drawn (Dental Knowledge, Milan, Italy) and then sent to the milling machine for production with a composite monoblock. After 4 months, when the implant was osteointegrated, it was not necessary to take another dental impression, and the definitive crown could be screwed in. Conclusion. The CAD/CAM technology is especially helpful in postextraction implant for aesthetic rehabilitation, as it is possible to immediately fix a provisional crown with an anatomic shape that allows an optimal healing process of the tissues. Moreover, the removal of healing abutments, and the use of impression copings, impression materials, and dental stone became unnecessary, enabling the reduction of the chair time, component cost, and patients discomfort. However, it is still necessary for scientific research to continue to carry out studies on this procedure, in order to improve the accuracy, the reliability, and the reproducibility of the results.