New species of Crossodonthina from Mangshan National Nature Reserve (Nanling National Forest Park), China (Collembola: Neanuridae)

Two new species of the genus Crossodonthina (Collembola: Neanuridae: Neanurinae: Lobellini) are recorded from Mangshan National Nature Reserve, Chenzhou City, Hunan Province and Ruyuan Yao Autonomous County, Guangdong Province, Central-South China. Crossodonthina clavata sp. nov. is characterized by 3+3 uncolored eyes on head; labral chaetotaxy as 0/2, 2; cephalic chaeta O present; cephalic tubercles Dl, L and So fused each other; mandible with 4 basal teeth and five fringed rami; maxilla with two lamellae and each lamella with two apical teeth. Crossodonthina acuminata sp. nov. can be recognized by 3 black eyes per side on head; mandible with 3 basal teeth and 8 rami; all cephalic tubercles independent, chaeta O on tubercle Fr present; cephalic tubercle Di, De on posterior area of head with 2 chaetae each, intermediate between cross and non-cross type chaetotaxy; tubercle De of Th. I with 3(2) chaetae; furcular remnant without chaeta. It is the first record of Neanuridae species from Mangshan National Nature Reserve.

Odontogenic Keratocyst in Anterior Mandible: A Case Report

Odontogenic Keratocyst (OKC) is a non-inflammatory developmental odontogenic cyst arises from cell rest of the dental lamina and most commonly occurs in the posterior of the mandible. OKC may be detected in patients of various age groups, from infants to seniors, and usually occurs in the third and fourth decades of the patient’s life. Female to male prevalence is 2:1 respectively. Mandible makes up 60% to 80% of cases and shows a specific tendency to involve the ramus and posterior area. Detection of OKC through clinical exams and radiography is to be suspected, and thus, confirmation via histopathology is needed. This study describes the occurrence of this lesion in a rare location in a 36 years old female patient.

Microbial evaluation of implant surface

Aim: The aim of the present study was to evaluate the microbial contamination in internal and external walls of cone morse implant walls. Methods: Eleven patients with edentulous mandibular posterior area were selected to received dental implants, divided into groups: submerged (S), non-submerged (NS), and immediately loaded (IL). Microbiological evaluations (microorganisms’ number, aerobic and anaerobic colony forming units (CFU) number and microorganisms’ qualification) were divided into internal and external collection of the implant walls, at different stages: T0 (surgical procedure), T2 (suture removal), T4 (reopening S group), T6 (suture removal S group), and T8 (abutment placement in S and NS). All data were submitted to statistical analyses, with confidence level of 0.05. Results: There was difference in number of microorganisms observed over time within the same group (p < 0.05). A difference was observed in CFU when evaluated within the same group over time (p < 0.05), except for the IL group. In internal collection, a predominance of non-formation of microorganisms was observed at T0 in all groups, while formation of Gram-positive Diplococci and Gram-positive Bacilli was observed at T8 (p>0.05). In external collection, an increase in number of microorganisms was observed at T0. Conclusion: There was no difference in microbial contamination among the evaluated groups. The microorganism’s colonization changed over time.

The VISTA Approach in Canine Disimpaction

Canine disimpaction is always a challenging orthodontic treatment overall, even when the impacted permanent canine is in a high position, especially when in tight relation with the upper incisors’ roots. Conventional treatment methods are usually not capable of performing the correct force direction, consisting of the contemporary movement in the distal and vestibular directions of the canine crown, often provoking, as side effects, the presence of decubitus on the mucous of the lips and cheeks or a poor final appearance of the periodontal support of the disimpacted canine. Among the different approaches, the vertical incision subperiosteal tunnel access (VISTA) technique shows good performance with regard to the direction of the forces and the canine’s periodontal conditions when erupted; it is usually realized through an elastic chain connected to a temporary anchorage device (TAD) in the posterior area. In this paper, a different protocol for the VISTA method is also presented, to be resorted to in cases of difficult miniscrew positioning due to the anatomic conditions or stage of dentitions. The new protocol also considers the use of nickel–titanium coil springs in order to avoid the need of frequent reactivation of the device and consequent patient discomfort, highlighting its advantages and indications with respect to the traditional approach.

Material Thickness Influence on Fracture Load of Polymer Infiltrated Ceramic Network CAD/CAM Restorations

Polymer infiltrated ceramics are hybrid materials that combine the strength of ceramics and the flexibility of polymers. The aim of this study was to compare the fracture load capacity of monolithic CAD/CAM crowns with different occlusal thicknesses, made from polymer infiltrated ceramic network. Fifteen full contour CAD/CAM crowns made of Vita Enamic with occlusal thicknesses of 0.5 mm, 1.0 mm and 1.5 mm were fabricated with a wet milling machine. Restorations were cemented on human molars with adhesive cement. Samples were loaded along the long axis until fracture, with a single static compressive force. A scanning electron microscope (SEM) was used to examine the fracture surface of specimens after the fracture. The results of this study reveals that the fracture load of the samples increased progressively with the occlusal thickness. The highest fracture value was recorded for1.5 mm occlusal thickness of the crown. No statistically significant difference was reported between the three experimental groups. It can be concluded that hybrid monolithic CAD-CAM crowns showed sufficient fracture strength to be used for single restorations in the posterior area, even with a reduced occlusal thickness.

Implant Placement after Closure of Oroantral Communication by Sinus Bone Graft Using a Collagen Barrier Membrane in the Shape of a Pouch: A Case Report and Review of the Literature

Oro-antral communication (OAC) acts as a pathway for bacteria between the maxillary sinus and oral cavity, and is a common complication after the removal of a dental implant or extraction of a tooth from the maxillary posterior area. In the case of an untreated OAC, oro-antral fistula develops and becomes epithelialized. We aimed to introduce a treatment for OAC closure via a sinus bone grafting procedure using bone tacks and a collagen membrane with an allograft. The procedure was performed by applying an absorbable membrane made in pouch form. This membrane acted as a barrier for closing the large sinus membrane perforation. Bone tacks were used to fix the membranes. Subsequently, the maxillary sinus was filled with the allograft, and the absorbable membrane was reapplied. Primary closure was achieved by performing a periosteum-releasing incision for a tension-free suture. After 6 months, sufficient bone dimensions were gained without any occurrence of maxillary sinusitis or recurrence of OAC. Additional bone grafts and implantation could be performed to rehabilitate the maxillary posterior area. We conclude that this technique might be a useful treatment for reconstructing the maxillary posterior area with simultaneous sinus bone graft and OAC closure.

A modified transalveolar sinus floor elevation approach with a bilaterally enlarged osteotomy

Sinus floor elevation is the most commonly used method for vertical bone augmentation in the maxillary posterior area. This clinical report describes a modified transalveolar approach to elevate the sinus floor when placing implants on a severely resorbed maxillary posterior ridge with a buccal-palatal distance of more than 8.0 mm. In this approach, the osteotomy prepared on the crestal is bilaterally enlarged to 8.0-10.0 mm. The enlarged osteotomies can provide better access for practitioners, so that instruments can touch directly to the sinus floor and the Schneiderian membrane can be elevated with a reduced risk of perforation.