Application of Tribology Concept in Dental Composites Field: A Scoping Review

Tribology is the discipline concerning the application of friction, lubrication, and wear concepts of interacting surfaces in relative motion. A growing interest has developed in tribology application in medical biomaterials, such as resin composites used in restorative dentistry. Yet, the keywords “tribology” and “biotribology” are little applied in the pertinent publications. The aim of this scoping review was to offer an overview of tribology application in dental composites research and to identify knowledge gaps and address future research. A literature search was conducted on Pubmed and Scopus databases and the studies investigating the tribological behavior of resin composites were included for qualitative synthesis. The majority of studies on dental tribology were published in the research areas of mechanical engineering/nanotechnology and differed in several methodological aspects. The preponderant engineering approach and the lack of standardized testing make the laboratory findings poorly informative for clinicians. Future research should focus on the tribological behavior of dental materials composites by means of an integrated approach, i.e., engineering and clinical, for improving development and advancement in this field of research

ATROPHIC POSTERIOR MANDIBLES TREATED WITH SANDWICH OSTEOTOMY WITHOUT MINISCREWS AND MINIPLATES: A CASE REPORT

The posterior mandible may be challenging due to insufficient height and width of the edentulous alveolar crestal bone. The aim of this case report was to use an inlay technique without the use of miniscrews and miniplates for the stabilization of grafted bone fragments. A 54-year-old patient was treated with a horizontal osteotomy performed 2-3 mm above the mandibular canal, and two oblique cuts were made using an ultrasonic. The final phase of the osteotomy was performed with a lever for dental extraction. One miniblock of equine bone was inserted between the coronal osteotomized segment and the mandibular basal bone. Particles of cortical-cancellous equine bone filled the residual space. A resorbable collagen membrane was used for covered the biomaterials and miniblock. Four months after surgery, a panoramic X-ray was taken before implant insertion. No dehiscence of the mucosa was observed at the marginal ridge of the mobilized fragment. Rx showed a mineralized zone between the osteotomized segment’s basal bone and coronal portion. This case report showed that equine collagenated blocks present higher stability, allowing to eliminate the use of miniscrews and miniplates, thus simplifying the sandwich technique

Volumetric evaluations of the maxillary sinus before and post regenerative surgery

OBJECTIVE: The purpose of this study was to investigate possible differences in the filling of the various recesses of the maxillary sinus after the procedure of sinus floor elevation in relation with the initial volume of the same and if the sinus volume can influence long-term graft dimensions, by using cone beam computed tomography (CBCT) as diagnostic analysis device. PATIENTS AND METHODS: This study included 32 sinuses corresponding to 16 patients referred for bilateral maxillary sinus augmentation procedures needing to increase the volume of the surgical site with the porcine cortical bone for dental implant placement in the posterior maxilla. The sinuses were analyzed by preoperative and postoperative (15 days and 6 months after sinus surgery) cone beam computed tomography. RESULTS: No statistically significant relations were observed between initial sinus dimensions and the entity of the contraction of the graft between T1 (15 days after surgery) and T2 (180 days after surgery). The behavior was the same either for the large sinus (> 15.65 cm3) and for the small one (< 15.65 cm3). Instead, about the filling of the various sinus recesses, a linear regression model was used to explain the difference between the mean preoperative and postoperative surgical spaces; in most of the samples, the filling of the anterior recess was ~15% of the total volume of the graft, i.e., the minor one among the main recesses. CONCLUSIONS: Our findings suggest that: (1) in the procedure of sinus floor augmentation by a lateral approach with deproteinized porcine bone there are no relations between the initial dimensions of the sinus and the long-term dimensional changes of the graft, and (2) that, among the main recesses of the sinus, the anterior one is generally the less filled

THE BONE-IMPLANT CONTACT AND OSSEOINTEGRATION OF DIFFERENT IMPLANT SURFACE TREATMENT: THE FINDINGS FROM A SYSTEMATIC REVIEW OF LITERATURE

The dental implant is associated with high long-term predictability for fixed rehabilitation in edentulous patients. The aim of the present review was to evaluate the state-of-art of dental implant surface treatment and their effect on osseointegration. The Pubmed/Medline, EMBASE, Cochrane Library databases has been screened to identify the histologic studies regarding the dental implant surfaces in vivo. The screening process revealed a total of 3173 papers with a total of 24 articles obtained by the manual search. A total of 482 duplicates have been removed and 2691 papers were assessed for the full-text evaluation. A total of 2527 articles were removed after the eligibility process and 149 articles were evaluated for the descriptive analysis. The implant osseointegration process is a complex combination of events that is oriented to an intimate interface between the dental implant surface and the host peri-implant tissues that oriented to produce a functional ankylotic relationship between the components under the masticatory loading

Microleakage and mechanical behavior of conical vs. internal hexagon implant-abutment connection under a cyclic load fatigue test

OBJECTIVE: The aim of the present investigation was to evaluate, by an in vitro simulation, the mechanical behavior of the conical vs. internal hexagon under cyclic load and the microleakage of the prosthetic connection of the fixture. MATERIALS AND METHODS: A standardized cyclic loading was performed considering the implant with conical connection (diameter 4 mm - length 10 mm) (CS) and internal hexagon connection (diameter 4 mm - length 10 mm) (IH). The toluidine blue infiltration has been evaluated with the paper cone test. RESULTS: After a total of 5x104 loads, the screw has been removed and the abutment appears solid and stable to the implant fixture for CS, while the IH was unstable. There was no infiltration of the toluidine marker in the connection interfaces of CS implants, while the IH was positive to the paper cone test. CONCLUSIONS: The study data showed that the conical connection showed higher stability compared to the internal hexagon connection under the loading and it is able to prevent bacterial microleakage. This effectiveness should be considered for the long-term maintenance of the peri-implant soft and hard tissues around the fixture

MECHANICAL ANALYSIS OF THE CONE MORSE ABUTMENT IMPLANT

After implant insertion and loading, crestal bone usually undergoes a process of remodelling and resorption. In order to reduce crestal bone loss, the “platform switching” technique has been proposed, in which the horizontal relationship between the outer edge of the implant and a smaller-diameter component is increased. The aim of the present work was to evaluate in vitro a fixture-abutment connection with cone morse and screw. Mechanical tests were carried out using a Lloyd 30K universal testing machine (Lloyd Instruments Ltd, Segensworth, UK). The load was applied on the coronal portion of the abutment with a crosshead speed of 5 mm/min, and the fracture load data were automatically recorded using Nexigen software (Nexigen, Batch Version 4.0, Issue 23, Lloyd Instruments Ltd, Segensworth, UK). The results indicated that the force necessary to induce a fracture when using the new fixture-abutment connection with cone morse and screw joint systems reached 1250±60 N. In conclusion, the fixture-abutment connection with the cone morse tested in this study presents a very high resistance

Rehabilitation of patients with thin ridges by conical expanders and immediate cone morse dental implant: a case report

BACKGROUND: Horizontal atrophic ridges need a regenerative procedure for implant positioning and fixed rehabilitation. Cone Morse taper implants are characterized by the intimate fitting of the prosthetic interface with the absence of microgaps and micromovements of the interfaces. The aim of this case report was to evaluate the clinical outcome of Cone Morse implant design in split crest augmentation treatment. CASE REPORT: A female patient with partial edentulism of atrophic posterior maxilla was treated for split crest procedure and implant-supported rehabilitation. A full-thickness flap was elevated, and horizontal and vertical osteotomic lines were produced with piezoelectric device. A total of 4 Cone Morse Taper implants (Universal III, Implacil de Bortoli, Brasil) were positioned and the site was grafted with bone substitute and covered by a heterologous membrane. CONCLUSIONS: A complete healing of the surgical site was evident at the follow-up with no evidence of bone resorption. No radiolucency or inflammatory aspects of the treated site were evident in the radiographic control. Simultaneous Cone Morse implants positioning with split crest technique seems to be a promising treatment for posterior maxillary rehabilitation of atrophic edentulous ridges

Wettability of mg-ha/Chitosan-based membrane surfaces: blood vs. autologous platelet liquid (APL)

OBJECTIVE: The physical and physical chemistry is able to influence the interaction of the scaffolds and bone substitutes with the body fluid and blood. The aim of the present investigation was to evaluate the wettability properties of an Mg-HA Chitosan-based Gel with blood vs. autologous platelet gel. MATERIALS AND METHODS: A total of 6 study groups were evaluated according to the Mg-HA Chitosan-based Gel thickness (1, 2 and 3 mm) and the fluids (blood vs. autologous platelet gel). The biomaterial wettability was conducted through the sessile drop technique. RESULTS: The study findings showed a significant difference in contact angle between the APL and blood groups (p0.05). CONCLUSIONS: In the present investigation, a similar MG/Ha gel membranes wettability was reported between APL and blood groups. In addition, a high hydrophilicity of MG/Ha gel membranes was reported with a potential advantage in terms of a more effective osteogenic capability in the clinical practice

Topical hemostatic agents in oral surgery: a narrative review

Sufficient hemostasis during oral surgical procedures is crucial for successful outcomes and to reduce healthcare resource utilization. The purpose of this narrative review is to give a rational insight into the management of bleeding in oral and dental practice through modern drugs. A narrative literature review has been performed on the present topic identifying all articles on Pubmed/Medline and Google Scholars. Acceptable hemostasis during oral surgery is also required to improve visibility and provide a dry operational area. Many oral surgeons, in their daily practice, encounter problems in controlling postoperative bleeding and use a topical hemostatic agent to promote platelet activation or aggregation to form a stable clot