Digital three-dimensional visualization of intrabony periodontal defects for regenerative surgical treatment planning

BACKGROUND: In the regenerative treatment of intrabony periodontal defects, surgical strategies are primarily determined by defect morphologies. In certain cases, however, direct clinical measurements and intraoral radiographs do not provide sufficient information on defect morphologies. Therefore, the application of cone-beam computed tomography (CBCT) has been proposed in specific cases. 3D virtual models reconstructed with automatic thresholding algorithms have already been used for diagnostic purposes. The aim of this study was to utilize 3D virtual models, generated with a semi-automatic segmentation method, for the treatment planning of minimally invasive periodontal surgeries and to evaluate the accuracy of the virtual models, by comparing digital measurements to direct intrasurgical measurements. METHODS: Four patients with a total of six intrabony periodontal defects were enrolled in the present study. Two months following initial periodontal treatment, a CBCT scan was taken. The novel semi-automatic segmentation method was performed in an open-source medical image processing software (3D Slicer) to acquire virtual 3D models of alveolar and dental structures. Intrasurgical and digital measurements were taken, and results were compared to validate the accuracy of the digital models. Defect characteristics were determined prior to surgery with conventional diagnostic methods and 3D virtual models. Diagnostic assessments were compared to the actual defect morphology during surgery. RESULTS: Differences between intrasurgical and digital measurements in depth and width of intrabony components of periodontal defects averaged 0.31 ± 0.21 mm and 0.41 ± 0.44 mm, respectively. In five out of six cases, defect characteristics could not be assessed precisely with direct clinical measurements and intraoral radiographs. 3D models generated with the presented semi-automatic segmentation method depicted the defect characteristics correctly in all six cases. CONCLUSION: It can be concluded that 3D virtual models acquired with the described semi-automatic segmentation method provide accurate information on intrabony periodontal defect morphologies, thus influencing the treatment strategy. Within the limitations of this study, models were found to be accurate; however, further investigation with a standardized validation process on a large number of participants has to be conducted

Harvesting of autogenous grafts for gingival recession coverage

The ultimate aim of periodontal plastic surgery is to create optimal pink esthetics through the reconstruction of gingival recessions. Application of autogenous soft tissue grafts is considered as a gold standard treatment modality with predictable esthetic outcomes for gingival recession coverage. Harvesting a free soft tissue graft from an esthetically irrelevant region of the oral mucosa using various techniques can prevent donor site complications around the adjacent teeth

Histological evaluation of human intrabony periodontal defects treated with an unsintered nanocrystalline hydroxyapatite paste

Objectives: The aim of the study was to clinically and histologically evaluate the healing of human intrabony defects treated with open flap surgery (OFD) and application of a new, resorbable, fully synthetic, unsintered, nanocrystalline, phase-pure hydroxyapatite (nano-HA). Materials and methods: Six patients, each of them displaying very advanced intrabony defects around teeth scheduled for extraction due to advanced chronic periodontitis and further prosthodontic considerations, were included in the study. Following local anaesthesia, mucoperiosteal flaps were reflected; the granulation tissue was removed, and the roots were meticulously debrided by hand and ultrasonic instruments. A notch was placed at the most apical extent of the calculus present on the root surface or at the most apical part of the defect (if no calculus was present) in order to serve as a reference for the histological evaluation. Following defect fill with nano-HA, the flaps were sutured by means of mattress sutures to allow primary intention healing. At 7months after regenerative surgery, the teeth were extracted together with some of their surrounding soft and hard tissues and processed for histological analysis. Results: The postoperative healing was uneventful in all cases. At 7months following surgery, mean PPD reduction and mean CAL gain measured 4.0 ± 0.8 and 2.5 ± 0.8mm, respectively. The histological analysis revealed a healing predominantly characterized by epithelial downgrowth. Limited formation of new cementum with inserting connective tissue fibers and bone regeneration occurred in three out of the six biopsies (i.e. 0-0.86 and 0-1.33mm, respectively). Complete resorption of the nano-HA was found in four out of the six biopsies. A few remnants of the graft particles (either surrounded by newly formed mineralized tissue or encapsulated in connective tissue) were found in two out of the six biopsies. Conclusion: Within their limits, the present results indicate that nano-HA has limited potential to promote periodontal regeneration in human intrabony defects. Clinical relevance: The clinical outcomes obtained following surgery with OFD + nano-HA may not reflect true periodontal regeneratio

A phase IIa randomized controlled pilot study evaluating the safety and clinical outcomes following the use of rhGDF-5/β-TCP in regenerative periodontal therapy

To present the safety profile, the early healing phase and the clinical outcomes at 24weeks following treatment of human intrabony defects with open flap debridement (OFD) alone or with OFD and rhGDF-5 adsorbed onto a particulate β-tricalcium phosphate (β-TCP) carrier. Twenty chronic periodontitis patients, each with at least one tooth exhibiting a probing depth ≥6mm and an associated intrabony defect ≥4mm entered the study. Ten subjects (one defect/patient) were randomized to receive OFD alone (control) and ten subjects OFD combined with rhGDF-5/β-TCP. Blood samples were collected at screening, and at weeks 2 and 24 to evaluate routine hematology and clinical chemistry, rhGDF-5 plasma levels, and antirhGDF-5 antibody formation. Plaque and gingival indices, bleeding on probing, probing depth, clinical attachment level, and radiographs were recorded pre- and 24weeks postsurgery. Comparable safety profiles were found in the two treatment groups. Neither antirhGDF-5 antibody formation nor relevant rhGDF-5 plasma levels were detected in any patient. At 6months, treatment with OFD + rhGDF-5/β-TCP resulted in higher but statistically not significant PD reduction (3.7 ± 1.2 vs. 3.1 ± 1.8mm; p = 0.26) and CAL gain (3.2 ± 1.7 vs. 1.7 ± 2.2mm; p = 0.14) compared to OFD alone. In the tested concentration, the use of rhGDF-5/β-TCP appeared to be safe and the material possesses a sound biological rationale. Thus, further adequately powered, randomized controlled clinical trials are warranted to confirm the clinical relevance of this new approach in regenerative periodontal therapy. rhGDF-5/β-TCP may represent a promising new techology in regenerative periodontal therap

Evaluation of Laser Speckle Contrast Imaging for the Assessment of Oral Mucosal Blood Flow following Periodontal Plastic Surgery: An Exploratory Study

The laser speckle contrast imaging (LSCI) is proved to be a reliable tool in flap monitoring in general surgery; however, it has not been evaluated in oral surgery yet. We applied the LSCI to compare the effect of a xenogeneic collagen matrix (Geistlich Mucograft®) to connective tissue grafts (CTG) on the microcirculation of the modified coronally advanced tunnel technique (MCAT) for gingival recession coverage. Gingival microcirculation and wound fluid were measured before and after surgery for six months at twenty-seven treated teeth. In males, the flap microcirculation was restored within 3 days for both grafts followed by a hyperemic response. During the first 8 days the blood flow was higher at xenogeneic graft comparing to the CTG. In females, the ischemic period lasted for 7-12 days depending on the graft and no hyperemic response was observed. Females had more intense and prolonged wound fluid production. The LSCI method is suitable to capture the microcirculatory effect of the surgical intervention in human oral mucosa. The application of xenogeneic collagen matrices as a CTG substitute does not seem to restrain the recovery of graft bed circulation. Gender may have an effect on postoperative circulation and inflammation

Fogeltávolítást követően visszamaradt szöveti defektus ellátása. Három eset ismertetése

Following tooth removal, three dimensional hard- and soft-tissue loss take place. Spontaneous healing makes the defect more severe and results in collapsing tissues. Implant placement is not feasible. In the aestethic zone even fixed partial dentures will not deliver the expected result. Our aim was to demonstrate that only ridge preservation enables implant placement and also provides excellent aestetic result even at frontal areas. CBCT was made before and 6-8 months after ridge preservation. Vertical and socket area measurements were carried out and compared in pre-, and postoperative images. Implant placement was feasible in all three cases; furthermore favourable buccal bone (4.24 mm, 6.22 mm, 9.57 mm) and area growth (129%, 145%, 167%) were measured. Ridge preservation provides appropriate therapy for complete reconstruction of tissues after tooth removal. Orv Hetil. 2017; 158(31): 1228-1234

Promjena volumena individualnog alogenog koštanog bloka mjerena pomoću dva softverska alata: nova tehnika za procjenu resorpcije grafta

Objective: The purpose of this case report was to present a method for the assessment of volumetric changes of bone blocks during healing and demonstrate its practicability by analysing the resorption of a preshaped allogeneic bone block used for the reconstruction of a complex maxillary defect. Materials and methods: CBCT-scans of a 19-year-old male treated with an allogeneic bone block were recorded pre-OP, post-OP, and following six months of healing. Graft shrinkage was assessed via two image matching tools, namely coDiagnostiX® and Slicer. A biopsy specimen was harvested along the implant canal at the time of implantation. Results: The osseous defect was successfully restored and advanced graft remodelling was found upon re-entry as confirmed by the histomorphometric and histologic analysis. The initial volumes of the graft determined via coDiagnostiX® and Slicer were 0.373 mL and 0.370 mL., respectively, while graft resorption after six months of healing was 0.011 mL (3.00%) and 0.016 mL (4.33%). Conclusions: The avoidance of bone harvesting and reduction of invasiveness display an important issue in dentoalveolar restorations. However, before grafting materials can be considered a safe alternative, understanding their clinical performance, especially resorption stability, is pivotal. The present case report demonstrates a limited resorption of the allogeneic bone block and further emphasizes the practicability of determining bone resorption by the here introduced method. As our investigation comprises solely one subject, the results should be considered with care and substantiated by further studies.Svrha istraživanja: Svrha ovog prikaza slučaja bila je predstaviti metodu za procjenu volumetrijskih promjena koštanih blokova tijekom cijeljenja i pokazati njezinu izvedivost analizom resorpcije prethodno oblikovanoga alogenoga koštanoga bloka koji se upotrebljava za rekonstrukciju složenoga maksilarnog defekta.Materijal imetoda: CBCT snimke 19-godišnjeg muškarca liječenoga alogenim koštanim blokom učinjene su prije operacije, poslije toga zahvata i šest mjeseci nakon cijeljenja. Skupljanje transplantata procijenjeno je s pomoću dvaju alata za podudaranje slika, odnosno alatima coDiagnostiX ® i Slicer. Biopsijski uzorak uzet je duž kanala implantata tijekom implantacije. Rezultati: Koštani defekt uspješno je rekonstruiran, a nakon ponovnog otvaranja pronađeno je napredno remodeliranje transplantata što je potvrđeno histomorfometrijskom i histološkom analizom. Početni volumeni transplantata određeni alatima coDiagnostiX ® i Slicer bili su 0,373 mL odnosno 0,370 mL, a resorpcija transplantata poslije šest mjeseci cijeljenja iznosila je 0,011 mL (3,00%) i 0,016 ml (4,33%). Zaključci: Izbjegavanje uzimanja kosti i smanjenje invazivnosti važan su problem u dentoalveolarnim rekonstrukcijama. Najoprije nego što se materijali za presađivanje mogu smatrati sigurnom alternativom, ključno je razumjeti njihovu kliničku učinkovitost, posebno stabilnost na resorpciju. Ovaj prikaz slučaja pokazuje ograničenu resorpciju alogenoga koštanoga bloka i dodatno ističe izvedivost određivanja resorpcije kosti ovdje predstavljenom metodom. Kako naše istraživanje obuhvaća samo jedan slučaj, rezultate treba pozorno razmotriti i potkrijepiti daljnjim istraživanjima

Blood flow kinetics of a xenogeneic collagen matrix following a vestibuloplasty procedure in the human gingiva-An explorative study

The aim of the present study was to investigate temporal and spatial blood flow patterns following vestibuloplasty procedures using a collagen matrix (CM) to get an insight into the timing and direction of neovascularization in the CM.Five patients were treated using a modified apically repositioned flap combined with a CM. Intraoral photographs and blood flow measurements by laser speckle contrast imaging were taken for 12 months. Thirty regions of interest in the graft and the surrounding mucosa were evaluated. The clinical parameters were assessed after 6 and 12 months. VEGF expression was analyzed in the wound fluid on days 2 and 4.At 6 months, the mean width of keratinized gingiva increased, but the thickness was unchanged. Scar formation was observed in all cases. Perfusion in the graft began to increase at the lateral and coronal edges and then spread concentrically toward the center. The apical side showed a significant delay in perfusion, the highest VEGF expression, and wound fluid production as well as the most abundant scar formation.Neovascularization occurs mainly from the lateral and coronal edges, which may limit the extent of the surgical area. Abundant scar formation may be explained by increased VEGF expression induced by prolonged ischemia in this area

Kísérletek szilícium egykristályon femtoszekundumos lézerrel

Femtoszekundumos lézer segítségével különböző felhasználási célokkal kísérleteztünk szilícium egykristályon. A kis fókuszfoltátmérő, az ultrarövid impulzushossz és a nagy energiasűrűség új utakat nyit meg az anyagmegmunkálásban; a kezelt anyagon kisebb lesz a hőhatásövezet (HAZ), valamint precízebb, jobb minőségű anyagmegmunkálás válik lehetővé. Munkánk során szilícium egykristályra mikrooszlopokat, valamint lézerindukált periodikus felületi struktúrákat készítettünk