Belén RETAMAL-VALDES (a) Marcio de Carvalho FORMIGA (a) Mariana Linhares ALMEIDA (a) Aretuza FRITOLI (a) Kadmo Azevedo FIGUEIREDO (a) Miriam WESTPHAL (a) Patricia GOMES (a) Magda FERES (a)

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The guided bone regeneration (GBR) technique has been used to achieve optimal bone volume augmentation and allow dental implant placement in atrophic maxilla and mandible, with predictable results and high survival rates. The use of bone substitutes has reduced the necessity of autogenous bone grafts, reducing the morbidity at the donor areas and thus improving the patients’ satisfaction and comfort. This clinical case report shows a clinical and histological evaluation of the bone tissue behavior, in a case that required the horizontal augmentation of the alveolar ridge, with the use of xenograft biomaterial and further dental implant placement. After six months of healing time, six implants were placed, and a bone biopsy was done. The histological analysis depicted some fragments of the xenograft bone graft, integrated with the new-formed bone tissue.

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When alveolar preservation procedures are not performed after tooth extraction, aesthetic and functional impairment could occur. Guided bone regeneration using polytetrafluoroethylene (PTFE) membranes has proven to be a simple alternative treatment that results in good maintenance of the alveolar bone for mediate/late implant placement. Therefore, this study compared the effect of alveolar preservation with the use of dense PTFE membranes, with and without xenograft material by Computerized tomography-based body composition (CTBC) analysis, after four months of the socket preservation procedure. A total of 29 teeth indicated for extraction. In the test group, the sockets were filled with bone graft biomaterial and subsequently coated with a dense PTFE membrane. In the control group, the sockets were filled with the blood clots and subsequently coated with a dense PTFE membrane. The results we found on the changes of the bone width and height after the procedures were: buccal plate: control group 0.46 mm, test group 0.91 mm; alveolar height: control group −0.41 mm, test group 0.35 mm; cervical third: control group −0.89 mm, test group −0.11 mm; middle third: control group −0.64, test group −0.50; and apical third: control group 0.09 mm, test group −0.14 mm. The use of a xenograft in conjunction with d-PTFE membranes proved to be superior to the use of the same membrane and blood clot only in regions of the crest, middle third, and alveolar height.

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Osseodensification is a new method of bone instrumentation for dental implant placement that preserves bulk bone and increases primary implant stability, and may accelerate the implant rehabilitation treatment period and provide higher success and survival rates than conventional methods. The aim of this retrospective study was to evaluate and discuss results obtained on immediate implant placement with immediate and delayed loading protocols under Osseodensification bone instrumentation. This study included private practice patients that required dental implant rehabilitation, between February 2017 and October 2019. All implants were placed under Osseodensification and had to be in function for at least 12 months to be included on the study. A total of 211 implants were included in the study, with a 98.1% total survival rate (97.9% in the maxilla and 98.5% in the mandible). For immediate implants with immediate load, 99.2% survival rate was achieved, and 100% survival rate for immediate implant placement without immediate load cases. A total of four implants were lost during this period, and all of them were lost within two months after placement. Within the limitations of this study, it can be concluded that Osseodensification bone instrumentation provided similar or better results on survival rates than conventional bone instrumentation.

Objectives The aims of this study were to compare the initial implant stability obtained using four different osteotomy techniques in low-density synthetic bone, to evaluate the instrument design in comparison to the implant design, and to determinate a possible correlation between the insertion torque and initial stability quotient (ISQ). Materials and methods Four groups were identified in accordance with the osteotomy technique used (n = 10 implants per group): group G1, osteotomy using the recommended drilling sequence; group G2, osteotomy using an undersized compactor drill; group G3, osteotomy using an undersized drill; and group G4, osteotomy using universal osseodensification drills. Two polyurethane blocks were used: block 1, with a medullary portion of 10 pounds per cubic foot (PCF 10) and with a 1 mm cortical portion of PCF 40, and block 2, with a medullary of PCF 15 and with a 2 mm cortical portion of PCF 40. Tapered implants of 4 mm in diameter and 11 mm in length were used. The insertion torque (IT) and ISQ were measured. The dimensions of the final instrument used in each group and the dimensions of the implant were used to calculate the total area of each part, and these data were compared. Results Differences between the four groups were found for IT and ISQ values depending on the technique used for the osteotomy in the two synthetic bone models (p < 0.0001). All groups showed lower values of initial stability in block 1 than in block 2. Conclusions Undersized osteotomies with instruments designed according to the implant body significantly increased the initial stability values compared to beds prepared with universal drills and using the drilling sequence standardized by the manufacturer.