Photobiomodulation Enhances the Healing of Postextraction Alveolar Sockets: A Randomized Clinical Trial With Histomorphometric Analysis and Immunohistochemistry.

PURPOSE: Wound healing of postextraction sockets is a complex process that permits to reach the bone reformation in about 3 months, and that could be characterized by the presence of some complications, mainly dependent on the duration of the surgery. The aim of this study is to evaluate the impact of photobiomodulation (PBMT) on the healing processes of mucosa overlying postextraction alveolus and on related complications. METHODS: Twenty systemically healthy patients who needed to extract both lower third molars were selected in a private clinic and included in this prospective split-mouth randomized clinical trial. Inclusion criteria were no smokers subjects with the necessity to extract both lower third molars with surgeries overlapping for duration and difficulty. A computer-based randomization procedure was permitted to choose the side, subject to PBMT, by means of a neodymium-doped YAG (Nd: YAG) laser (test) and controls. Both surgeries were performed by the same operator with a gap of 40 days. Twenty-two days after each surgery, a biopsy in correspondence to the alveolar mucosa of the socket was obtained from both sites and observed with an optical microscope and analyzed with histomorphometric analysis and immunohistochemistry. RESULTS: Each of the 20 participants included in this study (11 women and 9 men, nonsmokers, mean age 16 years in the range of 15 to 17 years) were subjected to the extraction of both lower third molars, and a side was treated as control, the other, as the test. The histomorphometric analysis and immunohistochemistry showed that the tested sites, contrary to controls, were characterized by a lower presence of inflammatory cells, a more mature epithelium and myofibroblasts incorporated in a network of fibers parallel to the basal membrane, with little positivity to alpha-SMA antibodies and anti-myosin but positivity to anti-desmin. CONCLUSIONS: In conclusion, PBMT accelerates the healing process of postextraction alveolus after third molar extraction.

Synthetic Scaffold/Dental Pulp Stem Cell (DPSC) Tissue Engineering Constructs for Bone Defect Treatment: An Animal Studies Literature Review.

BACKGROUND: Recently a greater interest in tissue engineering for the treatment of large bone defect has been reported. The aim of the present systematic review and meta-analysis was to investigate the effectiveness of dental pulp stem cells and synthetic block complexes for bone defect treatment in preclinical in vivo articles. METHODS: The electronic database and manual search was conducted on Pubmed, Scopus, and EMBASE. The papers identified were submitted for risk-of-bias assessment and classified according to new bone formation, bone graft characteristics, dental pulp stem cells (DPSCs) culture passages and amount of experimental data. The meta-analysis assessment was conducted to assess new bone formation in test sites with DPSCs/synthetic blocks vs. synthetic block alone. RESULTS: The database search identified a total of 348 papers. After the initial screening, 30 studies were included, according to the different animal models: 19 papers on rats, 3 articles on rabbits, 2 manuscripts on sheep and 4 papers on swine. The meta-analysis evaluation showed a significantly increase in new bone formation in favor of DPSCs/synthetic scaffold complexes, if compared to the control at 4 weeks (Mean Diff: 17.09%, 95% CI: 15.16-18.91%, p < 0.01) and at 8 weeks (Mean Diff: 14.86%, 95% CI: 1.82-27.91%, p < 0.01) in rats calvaria bone defects. CONCLUSION: The synthetic scaffolds in association of DPSCs used for the treatment of bone defects showed encouraging results of early new bone formation in preclinical animal studies and could represent a useful resource for regenerative bone augmentation procedures.

The Effects of Erbium-Doped Yttrium Aluminum Garnet Laser (Er: YAG) Irradiation on Sandblasted and Acid-Etched (SLA) Titanium, an In Vitro Study.

The treatment of peri-implantitis implies the decontamination of the surface of the fixture. This study aims to analyze the effect of the erbium-doped yttrium aluminum garnet laser (Er: YAG) on sandblasted and acid-etched (SLA) titanium. 30 titanium SLA disks were divided into three groups. In Group 1, the disks were left intact; on the contrary, both Groups 2 and 3 were irradiated with the Er: YAG laser at different settings, with a pulse duration of 300 µs and a period of 30 s. Group 2 was irradiated at 1 W and 100 mJ/pulse and Group 3 at 4 W and 400 mJ/pulse. The superficial changes at chemical, nano, and microscopical levels were detected through the use of Fourier-transform infrared spectroscopy, atomic force microscopy, and scanning electron microscope. The Kruskal-Wallis test, followed by the Dunn-Bonferroni Post Hoc analysis, detected the presence of statistically significant differences among the groups. The level of significance was p ≤ 0.05. Results showed that Er: YAG irradiation promoted a significant (p < 0.05) increase of oxides and a decrease of microscopical roughness and porosity on SLA disks. However, the protocol tested on group 3 seemed to be too aggressive for the titanium surface, as shown by the presence of micro-cracks and signs of coagulation, melting, and microfractures. In conclusion, Group 2 showed significantly minor surface alterations with respect to Group 3, and the increase of superficial oxide level, the decrease of porosity, and micro-roughness represent a positive alteration that could protect the materials against bacterial adhesion.

A Novel Technique to Increase the Thickness of TiO2 of Dental Implants by Nd: DPSS Q-sw Laser Treatment.

High bone-implant contact is a crucial factor in the achievement of osseointegration and long time clinical success of dental implants. Micro, nano, microtopography, and oxide layer of dental implants influence tissue response. The lasers were used for achieving an implant surface with homogeneous micro texturing and uncontaminated surface. The present study aimed to characterize the implant surfaces treated by Nd: DPSS Q-sw Laser treatment compared to machined implants. A total of 10 machined implants and 10 lasered surface implants were evaluated in this study. The implant surfaces were evaluated by X-ray Photoelectron Spectroscopy (XPS), Auger Electron Spectroscopy (AES), and metallography to characterize and measure the thickness of the oxide layer on the implant titanium surface. The machined surfaces showed a non-homogeneous oxide layer ranging between 20 and 30 nm. The lasered implant surfaces showed a homogeneous oxide layer ranging between 400 nm and 460 nm in the area of the laser holes, while outside the layer, thickness ranged between 200 nm and 400 nm without microcracks or evidence of damage. Another exciting result after this laser treatment is a topographically controlled, repeatable, homogeneous, and clean surface. This technique can obtain the implant surface without leaving residues of foreign substances on it. The study results indicate that the use of Nd: DPSS Q-sw laser produces a predictable and reproducible treatment able to improve the titanium oxide layer on the dental implant surface.

The relationship of domain-general serial order memory and reading ability in school children with and without dyslexia.

Recent evidence suggests that reading development when learning alphabetic languages is related to the underlying cognitive ability to maintain the serial order of information in short-term memory (STM). However, it remains unclear at which time point in reading development serial order STM is most important. Here, we established a crucial link between the reading development of primary school children and their serial order STM performance for both verbal and nonverbal materials. In a large cohort study of 113 Italian-speaking elementary school children in Grades 1-4, we investigated this relationship by implementing a novel double-probe design. In Experiment 1, we found that serial order STM performance was related to children's reading abilities, especially in Grades 2 and 3, corresponding to the training phase of grapheme-phoneme decoding skills. In Experiment 2, we assessed children with developmental dyslexia (DD) and found that their serial order STM performance was significantly lower than that of chronological age-matched controls (CA). It also differed from that of reading age-matched controls when accounting for individual reading performance. Furthermore, the CA group displayed an implicit serial order facilitation for item memory, whereas this implicit recruitment of serial order abilities was completely absent in children with DD. Our results suggest that the domain-general cognitive ability to maintain the serial order of information interacts with the development of reading competency, especially during a middle training phase of word reading, and this particular relationship is markedly impaired in children with DD.