- مبلغ: ۸۶,۰۰۰ تومان
- مبلغ: ۹۱,۰۰۰ تومان
The current study examined whether bone can regenerate into an open space fabricated inside the metal implant and maintain its quantity and quality at the early post-implantation healing periods. 12 conventional one piece screw type titanium dental implants (control group) and 12 hybrid dental implants with spiral side openings (0.58 mm wide) connected to hollow inner channel (experimental group) were bilaterally placed in each quadrant at the P3, P4 and M1 positions in mandible of 4 adult beagles following 2 months of post-extraction healing. Fluorescent bone labels to qualitatively evaluate newly formed bone tissues were administered at 2 and 4 weeks of post-implantation periods, respectively. 3 control and 3 experimental bone-implant constructs for each animal were dissected from 2 animals at each 3 and 6 weeks of post-implantation healing periods. Undecalcified specimens were prepared from each construct for histological analyses to measure bone-to-implant contact (BIC) and interfacial bone area (BA), and also for nanoindentation and scanning electron microscopy to assess elastic modulus (E) and composition of bone tissues surrounding the implants, respectively. A substantial amount of newly formed bone tissues were observed at the implant interfaces of both implant groups. Bone tissues successfully regenerate through the side openings and hollow inner channel of the experimental implant as early as 3 weeks of post-implantation healing. The E values of the newly formed bone tissues were measured comparable to those of normal bone tissues. The current results indicate that the new hybrid implant can conduct bone regeneration into the inner architecture, which likely improves stability of the implant system by enhancing integrity of implant with interfacial bone.
Dental implant surgery has a success rate higher than 94%, leading to more than a million dental implantations annually and a continually increasing number of clinical cases (Charyeva et al., 2012; Pjetursson et al., 2014; Greenstein and Cavallaro, 2014). This high success rate is guaranteed only when the quantity and quality of bone at the surgical site are conducive to the implant placement. However, most patients who need dental implantation have various levels of bone deficiency due to oral bone complications that cause the initial extraction of teeth and bone loss following the extraction (Greenstein and Cavallaro, 2014; Tonetti et al., 2008). For example, tooth extraction and disuse atrophy arising from delayed treatment can lead to loss of the alveolar ridge (Wang and Lang, 2012; Horowitz et al., 2012). As such, there is an increasing demand for a new dental implant system that can maintain its stability while minimizing influences from bone quantity and quality surrounding the implant.
The size and architecture of spiral side openings and hollow inner channel at the middle portion of the one-piece hybrid dental implant can conduct bone ingrowth at the early post-implantation healing period. The newly regenerated bone tissue in the inner space had comparable quality with the normal bone tissue. The quantity of new bone apposition at the thread portion of the hybrid implant was similar to that of the conventional screw type implant. The side openings could also improve quality of the newly forming interfacial bone tissue at the early post-implantation healing period. These results strongly support efficacy of the open inner space concept in the new hybrid implant as an effective scaffold to conduct active bone regeneration. Future application can include local drug delivery through the top opening of the hybrid implant to treat peri-implantitis and accelerate bone regeneration at less bone sites, critical size defects, and sinus lifting. With success of these approaches, the current hybrid system can expand the conventional concept of osseointegration.