Minerva stomatologica最新文献

Background: Root trunk length (RTL) plays an important role in the diagnosis, prognosis and treatment of periodontitis. The aim of this retrospective pilot study was to evaluate the RTL of first maxillary premolar and to study the correlation with age and sex in this value.

Methods: The sample included 110 cone beam computed tomography (CBCT) images comprising 220 maxillaries first premolars from systemically healthy patients aged between 18 and 70 years. The tooth length (TL), root length (RL) and RTL were measured (dependent variables). Age and sex were considered as independent variables.

Results: No statistically significant correlation was found between the RTL and the TL. Longer RL and longer RTL were observed in younger patients than older subjects only in the left maxillary premolars. On the other hand, the sex of the patients had no effect on either of the dependent variables. The single rooted maxillary premolars were more frequent (relative to those with two roots) in woman and in elderly patients.

Conclusions: A correlation between the age and the RTL and RL has been found but only in left premolars. Sex seemed to have only a slight correlation on the frequency of single-rooted teeth of the right side of the mouth. Further studies should be addressed to clarify the significance of the asymmetries observed in the present study between the two sides of the mouth with the aim of deepening the knowledge and understanding of the different variables that could be correlated with the RTL.

Background: Evidence shows lower chance for osseointegration of implants without sufficient primary stability. The present retrospective study observed bone level conical screw implants with textured surface without primary stability.

Methods: Twenty-six Stark conical screw implants, with V-Blast (Vanish Blast) surface treatment were placed with low primary stability, (insertion torque lower than 10 N/cm and visible mobility at lateral load of 250 g). A soft diet was prescribed. osseointegration was assessed applying 30 Ncm of reverse torque 6 months after placement.

Results: The 26 implants that did not achieve primary stability still had a survival rate of 96% after the observation period and were classified as successful according with ICOI Pisa consensus conference success, survival, failure classification .96% of the implants showed clinical osteointegration and were successfully restored. After 12 months, all implants remained functional.

Conclusions: It can be concluded that bone-level implants with V-Blast surface in absence of functional loading are able to achieve osteointegration, even with low primary stability.

Introduction: Dentistry, therefore implantology, prosthetics, implant prosthetics or orthodontics in all their variants, are medical and rehabilitative branches that have benefited greatly from these methods of investigation to improve the predictability of rehabilitations. We will examine the Finite Element Method and Finite Element Analysis in detail. This method involves the simulation of mechanical forces from an environment with infinite elements, the real one, to a simulation with finite elements.

Evidence acquisition: The study searched MEDLINE databases from 2008 to 2018. Human use of FEM in vitro studies reported a contribution on oral rehabilitation through the use of FEM analysis. The initial search obtained 296 citations. After a first screening, the present revision considered the English-language works referred to human application of the FEM published in the last 10 years. Finally, 34 full texts were available after screening.

Evidence synthesis: The ultimate aim of this review is to point out all the progress made in the field of bioengineering and therefore, thanks to this, in the field of medicine. Instrumental investigations such as FEM are an excellent tool that allows the evaluation of anatomical structures and any facilities for rehabilitation before moving on to experimentation on animals, so as to have mechanical characteristics and satisfactory load cycle testing.

Conclusions: FEM analysis contributes substantially to the development of new technologies and new materials in the biomedical field, being able to perform a large number of simulations without the need for patients or to perform human tests. Thanks to the 3D technology and to the reconstructions of both the anatomical structures and eventually the alloplastic structures used in the rehabilitations it is possible to consider all the mechanical characteristics, so that they can be analyzed in detail and improved where necessary. It is possible thanks to these methods to know what are the ideal characteristics of a material to promote an oral rehabilitation, so we know the characteristics, it remains only to take a step in the field of the industry for the construction of materials close to these characteristics.

Introduction: The aim of this study was to review the histologic evidence of reosseointegration and related influencing factors in experimental induced peri-implantitis.

Evidence acquisition: An electronic search was performed on Medline for animal studies that included a histometric evaluation of the amount of regenerated bone in contact with an implant surface. Questions raised in the study focused on the role of implant surfaces, bone regeneration and decontamination treatments in achieving reosseointegration. A detailed electronic search was then conducted on MEDLINE (PubMed) up to July 2017.

Evidence synthesis: One hundred and one articles were selected as abstract, thirty-seven articles assessed as full-text and sixteen finally included in the study. Reported measurements of reosseointegration varied significantly in the study, from 0 to 3.37 mm. There is histological evidence that reosseointegration can occur after treatment of ligature-induced peri-implantitis. However regenerated bone in contact with bone is generally restricted to the most apical portion of the peri-implant defect.

Conclusions: Animal studies of induced peri-implantitis seem to indicate that rough surfaces can enhance reosseointegration as compared to smooth surfaces. With regard to bone regeneration techniques and materials, submerged healing and barrier membranes have shown a positive effect on reosseointegration. No evidence exists, however, about the specific role of different bone substitutes and their ability to improve bone formation. Growth factors have been shown to improve reosseointegration in animal models, though additional study is required to confirm the data. Several decontamination treatments have been shown to promote reosseointegration compared to control; however no specific procedure has proven superior to others in achieving reosseointegration.

Background: Ultrasonic devices have a lot of dental application specially in hygiene and surgery. However there are some disadvantages like cut slowness and heat production. Prosthodontics application is less investigated. In particular the heat production could be an important factor for the clinician. In fact more than 5.5 °C temperature increasing could determine pulp necrosis during tooth preparation. The aim of this study is to investigate the increasing of temperature during finishing line repositioning and polishing phases using ultrasounds inserts and to verify if it remains within the limit of 5.5 °C.

Methods: A sample of 32 human molars (extracted for periodontal reasons) was selected. The teeth were endodontically treated and prepared with burs in order to obtain a prosthetic round chamfer preparation, leaving the apical portion pervious for inserting the thermocouple probe. Then, they were inserted in plaster cubes up to the cement-enamel junction. A wall has been selected for each tooth for margin repositioning and finishing and prepared with the piezoelectric instrument (Multipiezo Touch with TipHolder DB2, Mectron, Carasco, Genoa, Italy). A mechanical arm was used to standardize the operator-dependent parameters. These parameters were: the pressure exerted on the dental wall, the cutting length and the time required for margin repositioning and finishing. The test phase consisted in a first stage of margin repositioning using an regular ultrasound tip with a diamond grain of 120 micron (DB120, Mectron, Carasco, Italy) (group 1), followed by a second finishing step conducted by a extra fine ultrasound tip with a diamond grain of 60 micron (DB60, Mectron, Carasco, Italy) (group 2). Each test lasted 60 seconds: this was the time that the mechanical arm needed to accomplish 32 rides. During these stages the intrapulpal temperature has been recorded thanks to a thermocouple. The obtained temperature data were analyzed by Kruskal-Wallis test and Mann-Withney post-hoc test, without Bonferroni correction (P<0.001).

Results: The average pulpal temperature increase was 4.65 °C with a standard deviation of 0.99 °C for the DB 120 ultrasonic tip and 5.40 °C with a standard deviation of 0.84 °C for the DB 60 ultrasonic tip. However, neither of the instruments reach the medium critical level of 5.5°C reported in the literature, there are some single values who exceed it. There is statistically significant difference using tips with different granulometries within the two groups (P value =0.013).

Conclusions: Ultrasonic tools are very performing to achieve results in repositioning and polishing of prepared tooth. The in-vitro analysis show that the pulp temperature increasing remains within the safe limits literature shows. It is important underline the polishing phase is the most critical and the clinicians have to pay attention to irrigation and pression to

Background: The use of lasers at different wavelengths has been proposed in combination with conventional non-surgical periodontal treatment in order to improve the clinical outcome of periodontal disease. However, the clinical use of laser photonic energy is still the subject of research and debate because the antibacterial activity of the laser is dependent upon method, laser parameters, quantity of bacteria, species selected and photosensitizers used.

Methods: We evaluated the in-vitro bactericidal activity of 810 nm diode-laser irradiation in simultaneous photoablative and photodynamic mode against the major pathogenic bacterial organisms associated with periodontal inflammation and disease. We used indocyanine green as photosensitizer and the high-energy density of 161.7 J/cm2 or 215.0 J/cm2 for the photoablative-photodynamic irradiation.

Results: The bacteria were drastically affected by the 215.0 J/cm2 irradiation in the presence of indocyanine green. In fact, the number of Porphyromonas gingivalis and Prevotella intermedia was reduced by 99.9% (P<0.001), while the number of Fusobacterium nucleatum, Aggregatibacter actinomycetemcomitans, Tannerella forsythia and Actinomyces viscosus decremented by 83.3% (P<0.01), 86.8% (P<0.05), 75% (P<0.01) and 78.7% (P<0.001), respectively. P. gingivalis and P. intermedia were the only bacteria that were sensitive to the treatment with indocyanine green dye and 161.7 J/cm2 of laser irradiation (P<0.001).

Conclusions: Our preliminary in-vitro data suggest that simultaneous photoablative-photodynamic irradiation could be a promising therapy against a wide range of bacteria involved in periodontal disease. We believe that further additional in-vivo investigation is necessary, to enable a more complete picture of effectiveness within a clinical setting to be established. In addition, the use of a simultaneous photoablative-photodynamic therapy is suggested to reduce treatment time, without compromising the efficacy against the periodontal pathogens.

Background: In patients with fixed orthodontic treatment, good oral hygiene management is important to prevent complications such as caries, enamel demineralization, white spots, gingivitis, gingival hyperplasia and periodontitis. The aim of this experimental study is to compare the plaque and gingival indexes in patients with labial or lingual appliances.

Methods: Twenty patients with a mean age of 27±-4.95 years were selected; ten patients (eight females and two males) between 17 and 39 years were fitted with a labial appliance while ten patients (nine females and one male) between 16 e 36 years were fitted with a lingual appliance. The dental hygienist made an evaluation using the plaque index and the gingival index, motivated and instructed the patients with labial and lingual devices to perform correct home oral hygiene. The timepoint were the following: T0 before the bonding, T1 one month after the bonding, T2 three months after the bonding, T3 six months after the bonding.

Results: In the vestibular appliance at T0, the plaque index is significantly lower than the lingual device, but the bleeding index is significantly higher. Moreover, in both treatments, an increase in the parameters from T0 to T1, T2 and T3 was confirmed, and in the latter a linear increase trend both in the plaque index and in the gingival index can be observed.

Conclusions: The plaque and bleeding index increase gradually from T0 to T3, but there is no significant difference between the vestibular and lingual appliances.