Anti-resorptive effect of pamidronate on extraction socket wall in dogs

Occlusive membranes for guided regeneration of inflamed tissue defects

Guided bone regeneration aided by the application of occlusive membranes is a promising therapy for diverse inflammatory periodontal diseases. Symbiosis, homeostasis between the host microbiome and cells, occurs in the oral environment under normal, but not pathologic, conditions. Here, we develop a symbiotically integrating occlusive membrane by mimicking the tooth enamel growth or multiple nucleation biomineralization processes. We perform human saliva and in vivo canine experiments to confirm that the symbiotically integrating occlusive membrane induces a symbiotic healing environment. Moreover, we show that the membrane exhibits tractability and enzymatic stability, maintaining the healing space during the entire guided bone regeneration therapy period. We apply the symbiotically integrating occlusive membrane to treat inflammatory-challenged cases in vivo, namely, the open and closed healing of canine premolars with severe periodontitis. We find that the membrane promotes symbiosis, prevents negative inflammatory responses, and improves cellular integration. Finally, we show that guided bone regeneration therapy with the symbiotically integrating occlusive membrane achieves fast healing of gingival soft tissue and alveolar bone.

Restoring the electrical microenvironment using ferroelectric nanocomposite membranes to enhance alveolar ridge regeneration in a mini-pig preclinical model

The maintenance and incremental growth of the alveolar bone at the tooth extraction site, to achieve the required height and width for implant restoration, remains a major clinical challenge. Here, the concept of restoring the electrical microenvironment to improve the effects of alveolar ridge preservation (ARP) was investigated in a mini-pig preclinical model. The endogeneous electrical microenvironment of the dental alveolar socket was recapitulated by fabricating a biomimetic ferroelectric BaTiO₃/poly(vinylidene fluoridetrifluoroethylene) (BTO/P(VDF-TrFE)) non-resorbable nanocomposite membrane polarized by corona poling. The polarized nanocomposite membrane exhibited excellent electrical stability. After implantation with bone grafts and covering with the charged membrane in tooth extraction sites for three months, both the vertical and horizontal dimension resorption of the alveolar ridge were significantly prevented, as assessed by cone beam computed tomography (CBCT) analyses. Micro-CT analysis showed that the charged membrane induced significant enhancement of newly regenerated bone at the tooth extraction sites. Histological analysis further confirmed that the restoration of the electrical microenvironment significantly promoted buccal alveolar bone regeneration and maturation. In addition, the charged membranes can maintain their structural integrity during the entire implantation period and exhibit positive long-term systemic safety, as assessed by preclinical sub-chronic systemic toxicity. These findings thus provide an innovative strategy for restoring the electrical microenvironment to enhance ARP following dentition defect and edentulism, which could further advance prosthodontics implant technology.

Effect of collagen matrix on postoperative palatal fistula in cleft palate repair

Palatal fistula is a challenging complication following cleft palate repair. We investigated the usefulness of collagen matrix in the prevention of postoperative fistula. We performed a retrospective cohort study of patients with cleft palate who underwent primary palatoplasty (Furlow’s double opposing z-plasty) in Seoul National University Children’s Hospital. Collagen Graft and Collagen Membrane (Genoss, Suwon, Republic of Korea) were selectively used in patients who failed complete two-layer closure. The effect of collagen matrix on fistula formation was evaluated according to palatal ratio (cleft width to total palatal width) and cleft width. A total of 244 patients (male, 92 and female, 152; median age, 18 months) were analyzed. The average cleft width was 7.0 mm, and the average palatal ratio was 0.21. The overall fistula rate was 3.6% (9/244). Palatal ratio (p = 0.014) and cleft width (p = 0.004) were independent factors impacting the incidence of postoperative fistula. Receiver operating characteristic curve analysis showed that the cutoff values in terms of screening for developing postoperative fistula were a palatal ratio of 0.285 and a cleft width of 9.25 mm. Among nonsyndromic patients with values above those cutoffs, the rates of fistula development were 0/5, 1/6 (16.7%), and 4/22 (18.2%) for those who received Collagen Graft, Collagen Membrane, and no collagen, respectively. Collagen matrix may serve as an effective tool for the prevention of palatal fistula when complete two-layer closure fails, especially in wide palatal clefts. The benefit was most evident in Collagen Graft with thick and porous structure.

The Influence of Local Pamidronate Application on Alveolar Dimensional Preservation after Tooth Extraction-An Animal Experimental Study

The aim of this randomized, controlled animal exploratory trial was to investigate the influence of local application of aminobisphosphonate pamidronate during the socket preservation procedure. Mandibular premolars were extracted in five Göttingen minipigs. Two animals underwent socket preservation using BEGO OSS (n = 8 sockets) and three animals using BEGO OSS + Pamifos (15 mg) (n = 12 sockets). After jaw impression, cast models (baseline, eight weeks postoperative) were digitized using an inLab X5 scanner (Dentsply Sirona) and the generated STL data were superimposed and analyzed with GOM Inspect 2018 (GOM, Braunschweig). After 16 weeks, the lower jaws were prepared and examined using standard histological methods. In the test group (BEGO OSS + pamidronate), buccooral dimensional loss was significantly lower, both vestibulary (−0.80 ± 0.57 mm vs. −1.92 ± 0.63 mm; p = 0.00298) and lingually (−1.36 ± 0.58 mm vs. −2.56 ± 0.65 mm; p = 0.00104) compared with the control group (BEGO OSS). The test group showed a significant difference between vestibular and lingual dimensional loss (p = 0.04036). Histology showed cortical and cancellous bone in the alveolar sockets without signs of local inflammation. Adjuvant application of pamidronate during socket preservation reduces alveolar dimensional loss significantly. Further investigations with regard to dose–response relationships, volume effects, side effects, and a verification of the suitability in combination with other bone substitute materials (BSMs) are necessary.

The influence of local delivery of bisphosphonate on osseointegration of dental implants

Data sourcesThe databases searched were the Cochrane Library, PubMed/Medline, Embase, ISI Web of Knowledge, Scopus and SIGLE OpenGrey. Databases were searched with no restriction on year of publication or language.Study selectionRandomised controlled clinical trials (RCTs), prospective and retrospective studies, case-control studies and case series studies in humans were included. The test group received implants with the local delivery of bisphosphonates, controls received implants only. Studies involving patients with metabolic bone diseases or undergoing systemic medications for bone bio-modulation or immunosuppression or with relevant pathologies were excluded.Data extraction and synthesisThree authors independently selected studies with disagreements being resolved by discussion. Study quality was assessed by two reviewers using the Newcastle-Ottawa scale (NOS).ResultsThree articles published between 2010 and 2013 met the selection criteria. Sample size ranged from five to 39. Mean age was 52.6 to 66. Efficacy was assessed using radiographic analysis, implant stability quotient (ISQ) and histological assessment. Despite methodological differences, all articles reported positive results for osseointegration when a local bisphosphonate was used, either on the implant surface or direct application of a pharmacologically active compound at the surgical site or in the form of a gel directly at the surgical site. Greater implant stability, better implant survival rates and reduced peri-implant bone loss were recorded in the test groups compared with controls. As well as formation of lamellar bone trabeculae in intimate contact with the implants.ConclusionsThe local use of a bisphosphonate appears to favour the osseointegration of titanium implants in humans.