Dimensional and histomorphometric evaluation of biomaterials used for alveolar ridge preservation: a systematic review and network meta-analysis.

OBJECTIVES: This systematic review and network meta-analysis aimed to answer to the following questions: (a) In patients undergoing alveolar ridge preservation after tooth extraction, which grafting material best attenuates horizontal and vertical ridge resorption, as compared to spontaneous healing?, and (b) which material(s) promotes bone formation in the extraction socket? MATERIALS AND METHODS: The MEDLINE, SCOPUS, CENTRAL, and EMBASE databases were screened in duplicate for RCTs up to March 2021. Two independent authors extracted the data and assessed the risk of bias of the included studies. Primary outcomes were ridge horizontal and vertical dimension changes and new bone formation into the socket. Both pairwise and network meta-analysis (NMA) were undertaken to obtain estimates for primary outcomes and compare different grafting materials. RESULTS: Eighty-eight RCTs were included, with a total of 2805 patients and 3073 sockets. Overall, a total of 1740 sockets underwent alveolar ridge preservation with different materials (1432 were covered by a membrane). Pairwise meta-analysis showed that, as compared to spontaneous healing, all materials statistically significantly reduced horizontal and vertical shrinkage. According to the multidimensional scale ranking of the NMA, xenografts (XG) and allografts (AG), alone or combined with bioactive agents (Bio + AG), were the most predictable materials for horizontal and vertical ridge dimension preservation, while platelet concentrates performed best in the percentage of new bone formation. CONCLUSIONS: Alveolar ridge preservation is effective in reducing both horizontal and vertical shrinkage, as compared to untreated sockets. NMA confirmed the consistency of XG for ridge dimension preservation, but several other materials and combinations like AG, Bio + AG, and AG + alloplasts, produced even better results than XG in clinical comparisons. Further evidence is needed to confirm the value of such alternatives to XG for alveolar ridge preservation. Bio + AG performed better than the other materials in preserving ridge dimension and platelet concentrates in new bone formation. However, alloplasts, xenografts, and AG + AP performed consistently good in majority of the clinical comparisons. CLINICAL RELEVANCE: XG and Bio + AG demonstrated significantly better performance in minimizing post-extraction horizontal and vertical ridge dimension changes as compared with other grafting materials or with spontaneous healing, even if they presented the worst histological outcomes. Allografts and other materials or combinations (AG + AP) presented similar performances while spontaneous healing ranked last.

Cell-based therapies for the surgical treatment of periodontal intrabony defects: a systematic review.

OBJECTIVE: The aim of the study is to investigate the efficacy of cell-based therapy in the surgical treatment of periodontal intrabony defects. MATERIALS AND METHODS: PRISMA guidelines were followed, and the study protocol was regis-tered in PROSPERO. Electronic and hand searches were carried out on electronic databases and major international journals of periodontology. All randomized clinical trials (RCTs) comparing cell-based therapies com-bined with surgery to surgery alone for the treatment of periodontal intrabony defects were considered. Quality assessment was performed using the Cochrane Risk of Bias Tool for randomized clinical trials (RoB 2). Quantitative evaluation of data was performed by meta-analysis. RESULTS: Five hundred twenty-eight records were initially screened and 5 RCTs fulfilling the eligibility criteria were included. Periodontal ligament stem cells, dental pulp stem cells, periosteum-derived stem cells, gingival fibroblasts and their associated stem cells were used in combination with different surgical techniques to treat intrabony periodontal defects. Meta-analysis showed a statistically signif-icant effect in favor of cell-based groups for clinical attachment level gain (p=0.004), with a difference in means of 1.7 mm (95% CI 0.5; 2.9). This was replicated for intrabony defect depth reduction (p=0.006), with a difference in means of 1.3 (95% CI 0.4; 2.3). CONCLUSIONS: Cell-based therapies have been positively applied for the surgical treatment of intrabony periodontal defects with promising results. However, the results obtained should be interpreted with caution due to the low number of available RCTs, the study design heterogeneity, and the limited extension of the follow-up.

Carbon fibre versus metal framework in full-arch immediate loading rehabilitations of the maxilla - a cohort clinical study.

Frameworks made of carbon fibre-reinforced composites (CFRC) seem to be a viable alternative to traditional metal frameworks in implant prosthodontics. CFRC provide stiffness, rigidity and optimal biocompatibility. The aim of the present prospective study was to compare carbon fibre frameworks versus metal frameworks used to rigidly splint implants in full-arch immediate loading rehabilitations. Forty-two patients (test group) were rehabilitated with full-arch immediate loading rehabilitations of the upper jaw (total: 170 implants) following the Columbus Bridge Protocol with four to six implants with distal tilted implants. All patients were treated with resin screw-retained full-arch prostheses endowed with carbon fibre frameworks. The mean follow-up was 22 months (range: 18-24). Differences in the absolute change of bone resorption over time between the two implant sides (mesial and distal) were assessed performing a Mann-Whitney U-test. The outcomes were statistically compared with those of patients rehabilitated following the same protocol but using metal frameworks (control group: 34 patients with 163 implants - data reported in Tealdo, Menini, Bevilacqua, Pera, Pesce, Signori, Pera, Int J Prosthodont, 27, 2014, 207). Ten implants failed in the control group (6·1%); none failed in the test group (P = 0·002). A statistically significant difference in the absolute change of bone resorption around the implants was found between the two groups (P = 0·004), with greater mean peri-implant bone resorption in the control group (1 mm) compared to the test group (0·8 mm). Carbon fibre frameworks may be considered as a viable alternative to the metal ones and showed less marginal bone loss around implants and a greater implant survival rate during the observation period.

Effects of pulsed electromagnetic fields on swelling and pain after implant surgery: a double-blind, randomized study.

The aim of this split-mouth, double-blind, randomized study was to determine whether pulsed electromagnetic field therapy (PEMF) can improve swelling and the management of pain after full-arch immediate loading implant surgery. Eleven patients were selected for the study. Each patient received four distal tilted implants in the upper or lower jaw and underwent full-arch immediate loading rehabilitation. After surgery, two PEMF devices were applied to each patient, one on each cheek. In a random manner, one of these PEMF devices was switched on (test side); the other served as a placebo (control side). Forty-eight hours after surgery clinicians estimated postoperative swelling through photographic documentation, comparing the condition before and after surgery, while pain was assessed using a verbal rating scale. The patient's degree of comfort in relation to the PEMF devices was analyzed by questionnaire using a numerical rating scale. No statistically significant difference was observed between the test and control sides for swelling or pain (P>0.05). Most of the patients did not present swelling or pain at 48h after surgery, regardless of whether the PEMF device was activated or not. Various outcomes were found in the comfort evaluation. Within the limitations of this study, PEMF does not reduce postoperative swelling or pain after implant surgery.

Characterization of a murine model of cardiorenal syndrome type 1 by high-resolution Doppler sonography.

ABSTRACT: Cardiorenal syndrome type 1 (CRS-1) is the acute kidney disfunction caused by an acute worsening of cardiac function. CRS-1 is the consequence of renal vasoconstriction secondary to renin-angiotensin system (RAS) activation. No animal models of CRS-1 are described in literature. PURPOSE: To characterize a murine model of CRS-1 by using a high-resolution ultrasound echo-color Doppler system (VEVO2100). MATERIALS: Post-ischemic heart failure was induced by coronary artery ligation (LAD) in seven CD1 mice. Fifteen and thirty days after surgery, mice underwent cardiac and renal echo-color Doppler. Serum creatinine and plasma renin activity were measured after killing. Animals were compared to seven CD1 control mice. RESULTS: Heart failure with left ventricle dilatation (end diastolic area, p < 0.05 vs. controls) and significantly reduced ejection fraction (EF; p < 0.01 vs. controls) was evident 15 days after LAD. We measured a significant renal vasoconstriction in infarcted mice characterized by increased renal pulsatility index (PI; p < 0.05 vs. controls) associated to increased creatinine and renin levels (p < 0.05 vs. controls). CONCLUSIONS: The mice model of LAD is a good model of CRS-1 evaluable by Doppler sonography and characterized by renal vasoconstriction due to the activation of the renin-angiotensin system secondary to heart failure.

Gastric and masticatory performances in full-arch immediate loading rehabilitated patients.

Full-arch immediate loading implant rehabilitations provide patients with compromised dentition an effective treatment to improve their aesthetic and function. Aim of this prospective cohort study was to investigate the correlation between masticatory ability and gastric emptying rates among these patients. Ten subjects (five men and five women) with compromised dentition were tested in two occasions: before treatment and 30 days after the immediate loading rehabilitation. Masticatory ability was evaluated using the sieves test, and the gastric half emptying time (T(1/2)) was assessed by means of the 13C-octanoic acid breath test. A statistically significant increment (P < 0.005) in masticatory ability was found only in reference to the particles smaller than or equal to 4.75 mm, whereas the gastric emptying rate showed a statistically significant reduction between pre- and post-treatment (P = 0.003). A moderate negative correlation (rho = 0.64, P = 0.048) between the percentage change in masticatory ability and the percentage change in gastric emptying rate was evidenced. Patients with compromised dentition rehabilitated with full-arch immediate implant prostheses present a significant improvement of the gastric process.

Somatic embryogenesis and shoot regeneration from transgenic roots of the cherry rootstock Colt (Prunus avium×P. pseudocerasus) mediated by pRi 1855 T-DNA of Agrobacterium rhizogenes.

Hairy roots were obtained after inoculation with Agrobacterium rhizogenes strain NCPPB 1855 of the in-vitro-grown shoots of the cherry rootstocks Colt (Prunus avium×P. pseudocerasus) and Mazzard F12/1 (P. avium L.). Not all putatively transgenic roots were able to grow in hormone-free medium. Mazzard F12/1 roots, induced with A. rhizogenes, did not differentiate any shoot or embryo, while both somatic embryos and shoots differentiated from the transgenic roots of Colt in medium containing 1 mg/l 6-benzylaminopurine and 1 mg/l 1-naphthaleneacetic acid. Somatic embryos were capable of secondary embryogenesis, but few developed into whole plants. DNA hybridization showed both a different number of bands and signal intensity in each of the five transgenic shoot clones and embryos examined. In a morphogenetic in vitro test, leaf explants of the transgenic shoot clones showed an increased capacity to differentiate roots, although clones differed in their sensitivity to the hormone ratio. Clones from the transgenic shoots had not only an increased rooting ability when grown in vitro but also exhibited various hairy root phenotypes when cultured in vitro and when transferred into the greenhouse.