Orthodontics

To define the effect of APP treatments on the mechanical properties of enamel and on its ability to promote sealant bonding to unetched enamel. Human molar teeth were sectioned exposing flat enamel regions at the buccal and lingual surfaces. The specimens were divided into two substrate groups (etched and unetched) and distributed over three surface treatments (i) 5 slm Argon APP treatment, NaOH surface treatment, and (iii) compressed air application (control). The Enamel surfaces were characterized by SEM, IFM, and Goniometer instruments. For the mechanical tests nanoindentation and microshear bond strength were employed. Initial data evaluation comprised normality verification (SPS S software) and variance checking and the appropriated statistical analysis model employed. For all statistical inferences, significance was set at 0.05. SE was significantly higher for the etched and unetched group treated with Plasma relative to the NaOH and control groups. Nanoindentation testing det...

Lateral or vertical bone augmentation has always been a challenge, since the site is exposed to constant pressure from the soft tissue, and blood supply only exists from the donor site. Although, for such clinical cases, onlay grafting with autogenous bone is commonly selected, the invasiveness of the secondary surgical site and the relatively fast resorption rate have been reported as a drawback, which motivated the investigation of alternative approaches. This study evaluated the bone-forming capability of a novel nanoHA alloplast infused with collagen graft material made from biodegradable polylactic acid/polyglycolic acid versus a control graft material with the same synthesized alloplast without the nanoHA component and collagen infiltration. The status of newly formed bone and the resorption of the graft material were evaluated at 6 weeks in vivo histologically and three dimensionally by means of 3D microcomputed tomography. The histologic observation showed that newly formed bone ingrowth and internal resorption of the block were observed for the experimental blocks, whereas for the control blocks less bone ingrowth occurred along with lower resorption rate of the block material. The three-dimensional observation indicated that the experimental block maintained the external geometry, but at the same time successfully altered the graft material into bone. It is suggested that the combination of numerous factors contributed to the bone ingrowth and the novel development could be an alternative bone grafting choice.

Dual acid-etching is widely used to modify dental implant topography and enhance early bone healing. This study evaluated the histomorphometric, biomechanical, and histological bone response to acid-etched (AA) in comparison with grit-blasted/acid-etched (GB) and machined control (C) implants within sites of relatively low-bone remodeling rates. Implant surface topography was evaluated by scanning electron microscopy and optical interferometry (IFM). Six adult male sheep (n = 6) received 72 Ti-6Al-4V implants (n = 24 per surface) in both ilium (n = 12 per bone bilaterally). The implants remained for 3 and 6 weeks in vivo. The histomorphometric parameters bone-implant contact (BIC) and bone area fraction occupancy (BAFO) were evaluated. Biomechanical analysis consisted of torque-to-interface failure. IFM analysis showed the highest average surface roughness for GB and the highest density of summits and developed surface area percentage (P < 0.01) for AA. No difference was observed...

Objective: Primary stability has been regarded as a key factor to ensure uneventful osseointegration of dental implants. Such stability is often achieved by placing implants in undersized drilled bone. The present study evaluated the effect of drilling dimensions in insertion torque and early implant osseointegration stages in a beagle dog model. Method: Six beagle dogs were acquired and subjected to bilateral surgeries in the radii 1 and 3 weeks before death. During surgery, 3 implants, 4 mm in diameter by 10 mm in length, were placed in bone sites drilled to 3.2 mm, 3.5 mm, and 3.8 mm in diameter. The insertion torque was recorded for all samples. After death, the implants in bone were nondecalcified processed and morphologically and morphometrically (bone-to-implant contact and bone area fraction occupancy) evaluated. Statistical analyses were performed using the Kruskal-Wallis test followed by Dunn's post hoc test for multiple comparisons at the 95% level of significance. Re...

As we see more adults entering comprehensive orthodontic treatment, we must be more attuned to the implications of periodontal issues. In this updated chapter, Robert Vanarsdall, Ignacio Blasi and Antonino Secchi review periodontal issues that impact orthodontic tooth movement. They describe periodontal "high risk" factors, mucogingival considerations, and problems with ectopic as well as ankylosed teeth. A new section on alveolar decortication and augmentation grafting has been added to address the increased use of these procedures designed to develop the alveolar housing and potentially increase the speed of tooth movement. Excellent clinical examples are pictured throughout the chapter.

Rapid palatal expansion (RPE) has been used primarily to treat dental crossbites or for space gaining to prevent extractions with little or no attempt made to coordinate or normalize the transverse skeletal pattern. Traditionally, maxillary orthopedics has been performed using the dental units only as anchorage (e.g., Hyrax or Haas appliances). Dental anchorage not only has created limited skeletal orthopedic change, but also can cause significant adverse periodontal outcomes and unstable side effects. There is a clear correlation between buccal tooth movement and gingival recession and bone dehiscences. These adverse periodontal responses with RPE indicate the importance of early treatment. The beneficial periodontal effects of transverse skeletal correction have been a primary focus of our research for the past 35 to 40 years. We have emphasized the importance of correcting transverse skeletal discrepancy to: 1) prevent periodontal problems; 2) achieve greater dental and skeletal stability; 3) improve dentofacial esthetics by eliminating or improving buccal corridors; and 4) improve airway resistance. When it may be critical to save the natural dentition, we do not want to introduce adverse dental/skeletal changes for adolescent patients and/or patients with advanced periodontal disease. New advances in skeletal anchorage should permit orthopedic change without adverse dental changes by applying force directly to the maxillary bone; an innovative technique to maximize the skeletal maxillary changes in the transverse dimension is explained in this chapter. Furthermore, diagnosis of the transverse dimension—the use of cone-beam computed tomography (CBCT) for 3D evaluation of skeletal changes, the benefits of the skeletal transverse changes of the whole maxillofacial complex and its periodontal response, the changes in airway and non surgical RPE with bone-anchored appliances utilizing temporary anchorage devices (TADs)—is described and discussed.