DEPENDENCE OF THE RESTORATIVE EFFECT OF MACROPOROUS POLY(N-[2-HYDROXYPROPYL]-METHACRYLAMIDE HYDROGEL ON THE SEVERITY OF EXPERIMENTAL LACERATIVE SPINAL CORD INJURY

restoration of the spinal cord function presents a most severe biomedical issue nowadays. The aim of the study was to detect the macroporous poly(N-[2-hydroxypropyl]-methacrylamide hydrogel (PHPMA-hydrogel, HG) restorative effect dependence on the severity of the laceration spinal cord injury in young organisms. The male rats sample (~1-month-old, ~50 g, inbred Wistar line) was represented with 4 experimental groups: 1) spinal cord lateral hemisection at the level of ~Т12–Т13 segments (Sect; n=11); 2) spinal cord lateral hemiexcision ~1 mm long at the similar level (Exc; n=8); 3) spinal cord lateral hemisection at the similar level with immediate implantation of the hydrogel fragment into the trauma region (HGsect; n=11); 4) spinal cord lateral hemiexcision at the similar level with immediate implantation of the hydrogel fragment into the affected region (HGexс; n=6). The motor function and spasticity of the paretic hindlimb was estimated respectively by the technically modified Basso–Beattie–Bresnahan (ВВВ) and Ashworth, conditionally blinded to individual characteristics of all operated animals and previous study results. The observation lasted for ~5 months. The criteria of non-inclusion were as follows: the ipsilateral hindlimb function level in a week after the injury >9 points ВВВ, and the contralateral hindlimb function level during prolonged period ≤14 points ВВВ. The results were interpreted and presented according to the standardized time scale with interpolatory representation of the motor function and spasticity individual level in certain cases. Asymptotic stage differences between the studied groups and subgroups were stated during the first three weeks as well as in 8 weeks and 3 months after the injury. We found out that in a week after injury the motor function level in group Exc made up 0.9±0.5 points ВВВ, in group HGexc — 3.6±1.2 points, in group Sect — 5.9±1.1 points, in group HGsect — 6.0±1.0 points. In 5 months the motor function level in group Sect made up 9.5±1.0 points ВВВ, in group HGsect — 9.5±1.1 points, in group Exc — 0.8±0.3 points, in group HGexc — 4.5±1.8 points. At the same study stage the spasticity level in groups Sect and HGsect was, respectively, 0.8±0.2 and 0.8±0.3 points Ashworth, in group HGexc — 1.8±0.7 points, in group Exc — 3.6±0.3 points. Throughout the study no significant differences in groups Sect and HGsect have been detected, and in groups Exc і HGexc such differences were detected only in 5 weeks after the injury. The considerable difference of spasticity in groups Sect and HGsect was noted in 1 week after the injury, in groups HGexc and Exc — during first 2 months of the experiment. In groups Sect and Exc reliable difference of both motor function and spasticity level was found at all study stages. In groups HGsect and HGexc considerable difference of the motor function level was characteristic at all stages, except for the end of the 1st and 7th weeks, whereas spasticity level differences throughout the study remained insignificant. So, the tested hydrogel in young organisms shows positive effect only with severe trauma stages accompanied with extensive spinal cord defect.

Short-Term Evaluation of Guided Bone Reconstruction with Titanium Mesh Membranes and CGF Membranes in Immediate Implantation of Anterior Maxillary Tooth

Purpose. The aim of the present prospective study was to evaluate the effect of titanium mesh and concentrated growth factor (CGF) membranes in reconstructing severe labial bone defects during immediate implantation of anterior maxillary tooth. Methods. Patients with severe defects presenting on the anterior labial bone plate of maxillary were enrolled in this study. During immediate implantation, the titanium mesh was used to maintain the space of bone graft, collagen membrane, and xenograft bone that were used to guide bone regeneration (GBR). Cone beam computed tomography (CBCT) was used to measure the height and the labial bone thickness around the implant at the time of the second stage surgery, 6 months, 1 year, and 2 years after restoration. The pink esthetic score (PES) was used to evaluate the esthetic outcomes after restoration. Results. 18 patients were enrolled in this study. The survival rate of implants was 100%, and no complication was observed, except for 1 case of titanium mesh exposure which did not affect osteogenesis. In the second stage of surgery, the labial bone was completely reconstructed, and the top of the implant was covered with a small amount of new bone. The thickness of the labial bone was 3.01 mm (±0.23), 2.96 mm (±0.21), 2.93 mm (±0.19), and 2.92 mm (±0.16) at the time of the second stage surgery, 6 months, 1 year, and 2 years after restoration, respectively. The height of the marginal bone around implants was above the top of implant at the time of the second stage surgery and then reduced 0.72 mm (±0.07), 0.91 mm (±0.08), and 0.90 mm (±0.07) at the time point of 6 months, 1 year, and 2 years after restoration, respectively. The changes of bone thickness and height were statistically significant within one year, but stable after one year. The PES values showed the same tendency. Conclusions. With the limitation of the present prospective study, the combination of titanium mesh and CGF membrane could provide space maintenance for bone augmentation of alveolar bone defects and improve the bone regeneration in patients with severe labial bone defect when immediate implant of anterior maxillary.

CTNI-31. RESECTION AND SURGICALLY TARGETED RADIATION THERAPY FOR TREATMENT OF LOCALLY RECURRENT GBM IN 28 PROSPECTIVELY TREATED PATIENTS

INTRODUCTION Recurrent GBM is a diffuse disease and resection (R) alone does not routinely provide durable local control (LC) or prolonged overall survival (OS). We hypothesized R plus immediate radiation (RT) utilizing a novel brachytherapy device might achieve more durable LC and thereby secondarily improve OS. METHODS From 2/2013-2/2018, locally recurrent GBM were treated in a single arm trial (ClinicalTrials.gov, NCT#03088579) of R plus immediate implantation of a surgically targeted radiation therapy (STaRT) device utilizing Cs-131 in bioresorbable collagen tiles (GammaTile, GT Medical Technologies, Tempe AZ USA). RESULTS 28 patients (pts) were treated, 20 at first recurrence (range 1-3). Median age 58 (range 21-80), KPS 80 (60-100), female:male ratio 10:18. Median OS was 10.7 mo., radiographic LC 8.8 mo., and no first failure was local. MGMT, KPS, and sex were non-predictive. Post hoc analysis disclosed after R+STaRT, 17 pts (54%) received > 1 cycle of Sys (“Sys+”) and 13 (46%) did not (“Sys- “). Sys was given as adjuvant, salvage, or both, either alone or in combination. 15 pts received bevacizumab (BEV), 12 temozolomide (TMZ) and 8 lomustine (CCNU). Median OS (mo.) for Sys+ vs. Sys- was 15.1/6.5 (hazard ratio (HR) .38, p=.017); OS for BEV+ vs. BEV- was 16.7/4.5 (HR .38, p=.017), TMZ+ vs. TMZ- 17.5/6.7 (HR .40, p=.025) and for CCNU+ vs. CCNU- 17.5/7.9 (HR .61, p=.25), respectively. LC was 11.4 mo. for Sys+ vs. 2.1 mo. for Sys- (HR .44; p=.16). Three attributed AE occurred, 1 wound infection requiring surgery and 2 radiation brain effects, managed medically. CONCLUSION Post hoc analysis suggests R+STaRT+Sys may have the potential to impact OS in locally recurrent GBM, possibly by allowing sufficient time for effective but biologically slower treatments to have an impact. FDA clearance was received in 2018 for recurrent intracranial neoplasms and in 2020 for newly-diagnosed malignant brain tumors.

Immediate implant placement of BCS implant with and without platelet rich fibrin – An original research

Recently, immediate implant placement has rapidly gained popularity as this procedure definitively shortens the duration of the treatment, reduces the number of surgical sessions, and minimizes the discomfort of patients. However, the clinical effectiveness of immediate implantation in the molar regions has rarely been challenged. It has been reported that immediate implant placement does not seem to counteract alveolar ridge alteration and reconstruction after tooth extraction.

3D Considerations and Outcomes of Immediate Single Implant Insertion and Provisionalization at the Maxillary Esthetic Zone: A Long-Term Retrospective Follow-Up Study of Up to 18 Years

Aim: Long-term studies addressing the outcomes of single immediate implantation and provisionalization at the maxillary esthetic zone are needed. The current study aimed to assess such outcomes along a follow-up period of up to 18 years. Materials and methods: The current study is a continuation follow-up of our previously published up to 6-year follow-up study, dated between the years 2002–2008, performed in a private clinical practice in Tel-Aviv, Israel. A total of 15 patients (23 implants) who had been treated for single-tooth replacement at the maxillary esthetic zone since 2002, underwent clinical and radiographic follow-up evaluations. Primary outcomes included mean Marginal Bone Levels (MBL), with Bleeding on Probing (BOP), implant success rate, prosthetic and esthetic complications evaluated as secondary outcomes. Results: The implant success rate was at 100%. Bone remodeling processes were observed over the follow-up period, with 0.9 mm mean marginal bone loss observed during the first 6 years of observation, followed by −0.13 ± 0.06 mm mean loss after 6 to 18 years. The last finding suggests bone deposition, as reported by other studies (Donati et al., 2012). At the final radiographic evaluation, a mean MBL of 1.35 mm ± 0.16 was demonstrated. No differences with respect to implant type or site were found. A generalized absence of BOP and esthetic complications occurred in two cases as a result of continuous adjacent teeth eruption versus obvious implant ankylosis. Conclusions: Adhering to careful clinical protocols and 3D bone to implant considerations while immediately placing an anterior implant, this treatment approach offers both stable and esthetically acceptable results for the replacement of missing teeth at the maxillary esthetic zone.

Implications of virtual CBCT-based immediate implant planning for maxillary and mandibular first molars

The purpose of his study was to investigate the projected ridge-implant dimensions derived from virtual superimposition of implants on intact first molars mimicking immediate implantation in the mandible (Md1) and maxilla (Mx1) using cone-beam computed tomography (CBCT). The CBCT records of 41 patients (19 males and 22 females) with Md1 or Mx1 were collected. 10 mm-long cylindrical implants with different diameters were virtually positioned at prosthetically ideal angles into interradicular septum using CBCT software. Radiographic alveolar ridge height (ARH), alveolar ridge width (ARW), gap distance, and vertical distance from the implant platform to the alveolar crest were measured. Twenty Mx1s (48.8%) and 21 Md1s (51.2%) were included. The mean ARH values were 7.13 ± 4.32 mm and 15.64 ± 1.80 mm for Mx1 and Md1, respectively. 87.8% of mesiobuccal sites had gap distance > 2 mm when 6 mm diameter implants were used. Increasing implant diameter from 6 mm to 9 mm decreased the percentage of sites with ARW > 2 mm from 80.5% to 41.5% buccally and from 86.4% to 26.8% lingually. The mean vertical distance from the implant platform to the alveolar crest was 1.41 ± 1.09 mm buccally and 1.11 ± 1.10 mm lingually. Immediate implant placement of first molars, especially in the maxilla, requires stringent presurgical evaluation. Implants no wider than 6 mm placed into the interradicular septum may meet acceptable running room and alveolar plate thickness criteria if the jumping distance is grafted and further clinical trials are needed to confirm these findings in this virtual study