Ha-Rang Kim

The use of autologous venous blood for maxillary sinus floor augmentation in conjunction with sinus membrane elevation: an experimental study

BACKGROUND There have been reports of successful bone formation with sinus floor elevation induced by simply elevating the maxillary sinus membrane and filling the sinus cavity with a blood clot. PURPOSE We investigated the feasibility of maxillary sinus floor augmentation using the patients own venous blood in conjunction with a sinus membrane elevation procedure. MATERIALS AND METHODS An implant that protruded 8 mm into the maxillary sinus after sinus membrane elevation was placed in the maxillary sinus of six adult female mongrel dogs. The resulting space between the membrane and the sinus floor was filled with autologous venous blood retrieved from each dog. The implants were left in place for 6 months. RESULTS During the experimental period, the created space collapsed and the sinus membrane fell down onto the implant. A small amount of new bone formation occurred in the space created by the collapsed membrane. The average height of newly formed bone around the implants in the sinus was 2.7+/-0.7 mm on the buccal side and 0.6+/-0.3 mm on the palatal side. CONCLUSION The results of this pilot study indicate that blood clots do not have sufficient integrity to enable the sinus membrane to remain in an elevated position for therapeutically effective periods of time. Accordingly, it is recommended that this method be used only when a small amount of new bone formation is necessary around implants in the maxillary sinus cavity.

Flapless Implant Surgery Using a Mini‐Incision

BACKGROUND Traditional flapless implant surgery using a soft tissue punch device requires a circumferential excision of keratinized tissue at the implant site. A new flapless implant technique that can submerge implant fixtures is needed. PURPOSE This article describes a flapless implant surgery method using a mini-incision and compares the effects of soft tissue punch and mini-incision surgery on both the amount of osseointegration and the bone height around the implants using a canine mandible model. MATERIALS AND METHODS Bilateral, edentulated, flat alveolar ridges were created in the mandibles of six mongrel dogs. After a 3-month healing period, two implants were placed on each side of the mandible using either soft tissue punch or mini-incision procedures. After an additional 3-month healing period, a second stage surgery and transmucosal abutment attachment was performed for mini-incision implant cases. Following a 2-month healing period, the dogs were sacrificed to evaluate the osseointegration and bone height around the implants. RESULTS Average bone height was 9.6 ± 0.4 mm in the soft tissue punch group and 9.8 ± 0.3 mm in the mini-incision group (p > .05). Average osseointegration was 70.4 ± 6.3% in the soft tissue punch group and 71.2 ± 7.1% in the mini-incision group (p > .05). No significant differences were noted between the two groups in vertical alveolar ridge height or bone/implant contact. CONCLUSIONS Our findings support the clinical use of mini-incision implant surgery at sites where implants need to be protected below the soft tissue during the early phase of healing, particularly for patients with poor bone quality and/or low primary implant stability.

Effects of flapless implant surgery on soft tissue profiles: a prospective clinical study.

BACKGROUND Flapless implant surgery has been suggested as a suitable treatment modality for the preservation of soft tissue after implant placement. PURPOSE The purpose of this study was to determine the extent of soft tissue profile changes around implants after flapless implant surgery. MATERIALS AND METHODS A total of 44 patients received 76 implants using a flapless implant procedure. The marginal level of the peri-implant soft tissue was evaluated using dental casts 1 week, 1 month, and 4 months after implant placement. RESULTS The mean soft tissue levels around implants showed 0.7 ± 0.3 mm of coronal growth 1 week after surgery. At 1 month, the levels were 0.2 ± 0.2 mm coronal growth and at 4 months, the values were 0.0 ± 0.3 mm. Soft tissue profiles assessed 4 months after flapless implant placement were similar to profiles assessed immediately before implant placement. CONCLUSION Flapless implant surgery is advantageous for preserving mucosal form surrounding dental implants.

Effects of soft tissue punch size on the healing of peri-implant tissue in flapless implant surgery

OBJECTIVE In an attempt to help produce guidelines for the use of soft tissue punches, this animal study was undertaken to examine the effects of soft tissue punch size on the healing of peri-implant tissue in a canine mandible model. STUDY DESIGN Bilateral, edentulous, flat alveolar ridges were created in the mandibles of 6 mongrel dogs. After a 3-month healing period, 3 fixtures (diameter 4.0 mm) were placed on each side of the mandible using 3-mm, 4-mm, or 5-mm soft tissue punches. After subsequent healing periods of 3 weeks and 3 months, the peri-implant mucosa was evaluated using clinical, radiologic, and histometric parameters, which included gingival index, bleeding on probing, probing pocket depth, marginal bone loss, and vertical dimension measurements of the peri-implant tissues. RESULTS The results obtained showed significant differences (P < .05) between the 3-mm, 4-mm, and 5-mm tissue punch groups for the length of the junctional epithelium, probing depth, and marginal bone loss at both 3 weeks and 3 months after implant placement. When the mucosa was punched with a 3-mm tissue punch, the length of the junctional epithelium was shorter, the probing depth was shallower, and less crestal bone loss occurred than when using a tissue punch with a diameter >or=4 mm. CONCLUSIONS The results show that the size of the soft tissue punch plays an important role in achieving optimal healing. The findings support the use of a tissue punch slightly narrower than the implant itself to obtain better peri-implant tissue healing around flapless implants.