ABSTRACT
The success of osseointegration depends on many factors. With temperatures beyond a 47 °C threshold over 1 min, bone survival may be impaired. The purpose of the study was to evaluate, in fresh human cadaver tibiae, the temperature changes during osteotomy preparations using two straight and two tapered implant systems' drills, external irrigation, and varying revolutions per minute (RPM). The tibiae from a fresh female cadaver were harvested bilaterally. Two tapered and two straight design drills were assessed. Two-hundred and forty osteotomies were prepared at 6 mm depth following the drill sequence of the manufacturers' protocol for each drilling speed. Difference in temperature (ΔΤ) was calculated by subtracting the baseline from the maximum temperature (ΔT = Tmax - Tbase). Drill design and drill diameter, as independent variables or synergistically, had a significant effect on ΔΤ. Tapered drills: As the drill diameter increased, ΔΤ increased at all RPM. Straight drills: As the drill diameter increased, ΔΤ remained constant or slightly decreased at all RPM. Drill diameter and design had a significant effect on ΔΤ in human tibiae, which never exceeded the critical threshold of 47 °C. Tapered drills caused significantly greater heat production compared to straight drills.
ABSTRACT
OBJECTIVE: The purpose of the present study was to present vertical ridge augmentation (VRA) with the use of cross-linked resorbable membrane, tenting screws, and a combination grafting technique. REPORT: Three cases are presented. Case 1: A 67-year-old ASA II patient required VRA at the areas of the mandibular left second premolar and first molar. Flap management was performed with the use of periosteal release on the buccal aspect and 23 mm of mylohyoid muscle release on the lingual aspect. VRA was completed with the use of four self-tapping tenting screws, and 1:1 mix of anorganic bovine bone matrix (ABBM) and particulate mineralized bone allograft. A cross-linked resorbable membrane was placed over the buccal and lingual aspect, and a double line of suturing was performed to secure the tension-free closure. Twelve months postoperatively, 4 mm of VRA was confirmed with CBCT. Two implants were placed with >35 Ncm primary stability. Case 2: A 64-year-old ASA I patient required VRA at the area of the maxillary first premolar. Flap management was performed with the use of periosteal release on the buccal aspect and VRA was performed with a 9-mm self-tapping screw, 1:1 mix of ABBM and particulate mineralized bone allograft, a cross-linked resorbable membrane, and a double line of suturing. Twelve months postoperatively, VRA of 6.2 mm on the buccal aspect and 7.9 mm on the lingual aspect were confirmed with CBCT. An implant was placed with > 35 Ncm primary stability in combination with horizontal ridge augmentation. Case 3: A 70-year-old ASA II patient required horizontal and VRA at the area of the mandibular left canine. Following extraction, a lateral pedicle sliding flap was completed to enhance the soft tissue volume of the site. After 6 weeks, flap management was performed with the use of buccal periosteal release, VRA was completed with two self-tapping screws, 1:1 mix of ABBM and particulate mineralized bone allograft, a cross-linked resorbable membrane, and a double line of suturing. Eight months postoperatively there was 5.3 mm of bone regeneration on the vertical dimension and 3.9 mm on the horizontal dimension. An implant was placed with primary stability of 45 Ncm. CONCLUSION: Successful VRA can be achieved with proper flap management to achieve tension-free closure, a cross-linked collagen membrane, tenting screws, and a combination grafting technique. The VRA ranged from 4.0 to 7.9 mm.
