Detection and Segmentation of Radiolucent Lesions in the Lower Jaw on Panoramic Radiographs Using Deep Neural Networks.

Background and Objectives: The purpose of this study was to develop and evaluate a deep learning model capable of autonomously detecting and segmenting radiolucent lesions in the lower jaw by utilizing You Only Look Once (YOLO) v8. Materials and Methods: This study involved the analysis of 226 lesions present in panoramic radiographs captured between 2013 and 2023 at the Clinical Hospital Dubrava and the School of Dental Medicine, University of Zagreb. Panoramic radiographs included radiolucent lesions such as radicular cysts, ameloblastomas, odontogenic keratocysts (OKC), dentigerous cysts and residual cysts. To enhance the database, we applied techniques such as translation, scaling, rotation, horizontal flipping and mosaic effects. We have employed the deep neural network to tackle our detection and segmentation objectives. Also, to improve our model's generalization capabilities, we conducted five-fold cross-validation. The assessment of the model's performance was carried out through metrics like Intersection over Union (IoU), precision, recall and mean average precision (mAP)@50 and mAP@50-95. Results: In the detection task, the precision, recall, mAP@50 and mAP@50-95 scores without augmentation were recorded at 91.8%, 57.1%, 75.8% and 47.3%, while, with augmentation, were 95.2%, 94.4%, 97.5% and 68.7%, respectively. Similarly, in the segmentation task, the precision, recall, mAP@50 and mAP@50-95 values achieved without augmentation were 76%, 75.5%, 75.1% and 48.3%, respectively. Augmentation techniques led to an improvement of these scores to 100%, 94.5%, 96.6% and 72.2%. Conclusions: Our study confirmed that the model developed using the advanced YOLOv8 has the remarkable capability to automatically detect and segment radiolucent lesions in the mandible. With its continual evolution and integration into various medical fields, the deep learning model holds the potential to revolutionize patient care.

Influence of titanium implant macrodesign on peri-implantitis occurrence: a cross-sectional study.

OBJECTIVES: To assess whether implant macrodesign parameters interacting with implant time in function (Tf) could influence the peri-implantitis occurrence. MATERIALS AND METHODS: One hundred and two patients (55.17 ± 11.2 years old) with diagnosed early/moderate peri-implantitis around endosseous implants with implant-supported prosthetics reconstruction (n = 139) were recruited. Implant macrodesign (implant shape, thread number, implant collar), clinical parameters (peri-implant probing depth (PPD), clinical attachment level (CAL), keratinised tissue width (KTW), plaque index, bleeding on probe), implant placement localisation and region, and Tf were assessed and compared. RESULTS: Peri-implantitis occurred approximately 6.1 ± 3.38 years after implant loading. There was a significant positive correlation between the implant macrodesign and Tf. Peri-implantitis rates were statistically significantly higher in implants with a cylindric shape and triple-thread in the posterior part of the mandible (p = 0.037 and 0.012, respectively). The thread number and implant shape interacting with Tf showed statistically significant influences on CAL and PPD increase (p < 0.05). Results indicated a statistically positive interaction between Tf and KTW decrease around the implants with microthreaded collar (p < 0.001). CONCLUSION: Peri-implantitis might be presented as a time-dependent disease. Implant-based factors, such as Tf and implant macrodesign, could influence peri-implantitis occurrence, exacerbate clinical parameters, and promote progressive bone loss. CLINICAL RELEVANCE: Peri-implantitis can be affected by implant macrodesign and Tf. The implant body shape, thread number, and design of the implant collar may be considered peri-implantitis-related risk indicators that should be taken into account in proper implant planning and therapy.

Antimicrobial Efficacy and Permeability of Various Sealing Materials in Two Different Types of Implant-Abutment Connections.

The presence of a microgap along an implant-abutment connection (IAC) is considered the main disadvantage of two-piece implant systems. Its existence may lead to mechanical and biological complications. Different IAC designs have been developed to minimise microleakage through the microgap and to increase the stability of prosthodontic abutments. Furthermore, different sealing materials have appeared on the market to seal the gap at the IAC. The purpose of this study was to evaluate the antimicrobial efficacy and permeability of different materials designed to seal the microgap, and their behaviour in conical and straight types of internal IACs. One hundred dental implants with original prosthodontic abutments were divided into two groups of fifty implants according to the type of IAC. Three different sealing materials (GapSeal, Flow.sil, and Oxysafe gel) were applied in the test subgroups. The contamination of implant-abutment assemblies was performed by a joint suspension containing Candida albicans and Staphylococcus aureus. It was concluded that the IAC type had no significant influence on microleakage regarding microbial infection. No significant difference was found between the various sealing agents. Only one sealing agent (GapSeal) was found to significantly prevent microleakage. A complete hermetic seal was not achieved with any of the sealing agents tested in this study.

Mesenchymal Stem Cells Based Treatment in Dental Medicine: A Narrative Review.

Application of mesenchymal stem cells (MSC) in regenerative therapeutic procedures is becoming an increasingly important topic in medicine. Since the first isolation of dental tissue-derived MSC, there has been an intense investigation on the characteristics and potentials of these cells in regenerative dentistry. Their multidifferentiation potential, self-renewal capacity, and easy accessibility give them a key role in stem cell-based therapy. So far, several different dental stem cell types have been discovered and their potential usage is found in most of the major dental medicine branches. These cells are also researched in multiple fields of medicine for the treatment of degenerative and inflammatory diseases. In this review, we summarized dental MSC sources and analyzed their treatment modalities with particular emphasis on temporomandibular joint osteoarthritis (TMJ OA).

Evaluation of Efficiency of Polymerization, Surface Roughness, Porosity and Adaptation of Flowable and Sculptable Bulk Fill Composite Resins.

A new category of commercial bulk fill composite resins (CRs) enables the placement of 4-mm-thick layers as an alternative to the traditional time-consuming incremental technique. The purpose of the present study was to compare the efficiency of the polymerization, adaptation and porosity of two high-viscosity 'sculptable' bulk fill CRs (Filtek™ Bulk Fill (3M™ ESPE, St. Paul, MN, USA) and Tetric EvoCeram® Bulk Fill (Ivoclar Vivadent AG, Schwan, Liechtenstein)) and two low-viscosity 'flowable' bulk fill CRs (SureFil® SDR™ flow (Dentsply Sirona, Charlotte, NC, USA) and Tetric EvoFlow® Bulk Fill (Ivoclar Vivadent AG, Schaan, Liechtenstein)). Cylindrical samples of the bulk fill CRs (4 mm height × 10 mm diameter) were analyzed by Fourier-transform infrared spectroscopy (FTIR) and atomic force microscopy (AFM). Additionally, occlusal cavities were prepared in twelve extracted human molars and restored with the bulk fill CRs (n = 3 for each CR). The adaptation and porosity of the bulk fill CRs were evaluated by X-ray microcomputed tomography (µCT) with a 3D morphometric analysis, and the adaptation was also analyzed by scanning electron microscopy (SEM) on longitudinal vestibulo-oral sections of the restored teeth. The AFM analysis demonstrated that the surface roughness of the SureFil® SDR™ flow was higher than that of the Tetric EvoFlow® Bulk Fill and that the surface roughness of Filtek™ Bulk Fill was higher than that of Tetric EvoCeram® Bulk Fill. µCT and SEM confirmed that the flowable bulk fill CRs had excellent adaptation to the cavity walls. The 3D morphometric analysis showed the highest and lowest degrees of porosity in Filtek™ Bulk Fill and Tetric EvoFlow® Bulk Fill, respectively. In general, the flowable bulk fill CRs exhibited better adaptation, a higher efficiency of polymerization and lower porosity than the sculptable materials.

Influence of different laser-assisted retrograde cavity preparation techniques on bond strength of bioceramic-based material to root dentine.

The purposes of the study were to evaluate the bond strength of bioceramic TotalFill root repair material (RRM) in retrograde cavities prepared using Er:YAG and Er,Cr:YSGG laser and steel bur, and to analyze failure modes. The root canals of 30 single-rooted teeth were endodontically treated, their root-ends were resected using a diamond bur, and the teeth were randomly divided into three groups (N = 10) according to the retrograde cavity preparation technique: (1) Er:YAG laser, (2) Er,Cr:YSGG laser, and (3) steel bur. All retrograde cavities were filled with the TotalFill RRM which was prepared according to the manufacturers' instructions. Push-out test was performed using universal testing machine, and failure mode was analyzed using a scanning electron microscope. The data were analyzed using one-way ANOVA, post hoc analysis with Bonferroni correction, and Fisher-Freeman-Halton exact test (p < 0.05). In the Er:YAG-, Er,Cr:YSGG-, and steel bur-prepared cavities, mean bond strengths (MPa) were 12.76, 8.44, and 6.01, respectively. The bond strength of the TotalFill RRM to dentin was significantly higher in the Er:YAG laser compared with the steel bur-prepared cavities (p = 0.004). The bond strength was not significantly different between the Er:YAG and Er,Cr:YSGG cavities (p = 0.074) and between the Er,Cr:YSGG and bur cavities (p = 0.648). In the cavities prepared by the Er,Cr:YSGG laser and bur, the failure mode of the TotalFill RRM was predominantly mixed, then adhesive and cohesive. In the Er:YAG laser-prepared cavities, the most common failure mode was adhesive, followed by mixed type and no cohesive failure. The bond strength of the TotalFill RRM to dentin was highest in the group of retrograde cavities prepared by the Er:YAG laser.

Effect of Different Laser Treatments on the Bond Strength of Intracanal Fiber Posts Cemented with a Self-Adhesive Resin Cement.

PURPOSE: To evaluate the influence of laser-activated irrigation by Er:YAG and Er:YSGG (LAI) protocols and Nd:YAG laser irradiation on the bond strength of self-adhesively cemented fiber posts to root canal dentine. MATERIALS AND METHODS: The study sample consisted of 84 human single-rooted permanent teeth instrumented with ProTaper Next technique. After obturation, post space preparations were created for fiber-reinforced composite posts. The prepared specimens were divided according to the laser treatment of the post space preparations: group 1: LAI (Er:YAG) + saline solution (pulse energy: 20 mJ, repetition rate: 15 Hz); group 2: LAI (Er:YAG) + QMiX solution (pulse energy: 20 mJ, repetition rate: 15 Hz); group 3: LAI (Er,Cr:YSGG) + saline solution (pulse energy: 62.5 mJ, 20 Hz); group 4: LAI (Er,Cr:YSGG) + QMiX (pulse energy: 62.5 mJ, 20 Hz); Nd:YAG laser (pulse energy: 100 mJ, 10 Hz). Fiber-reinforced posts were cemented with a self-adhesive cement. The bond strength was evaluated by the push-out bond strength test, and the mode of failure was determined under a stereomicroscope. Kruskal-Wallis test was used for the intergroup comparative analysis with 5% level of significance. RESULTS: The highest bond strength was recorded in the Er:YAG + QMiX group (mean 3.401 MPa) (p < 0.05), followed by the Er,Cr:YSGG and the Er:YAG + saline solution (mean 1.111 MPa and 1.094 MPa, respectively), which did not differ significantly (p = 0.232). The irradiation with the Nd:YAG laser caused similar bond strength as the Er,Cr:YSGG + QMiX (p = 0.942). CONCLUSION: All laser protocols enhanced the bond strength of the self-adhesive cement in root canals compared to only saline irrigation. The bond strength of the self-adhesive cement depended on the laser parameters and irrigant used for the LAI.

EVALUATION OF INNOVATIVE DIGITALLY CONTROLLED ER:YAG LASER IN SURGICAL TREATMENT OF ORAL LEUKOPLAKIA - A PRELIMINARY STUDY.

The use of lasers for treatment of oral leukoplakia has gained a lot of interest in the past years, however, data on the use of Er:YAG laser are scarce. The aim of this study was to compare the efficacy of Er:YAG laser and 1% topical isotretinoin in the treatment of 27 oral leukoplakia patients. Er:YAG laser (LightWalker AT, Fotona, Slovenia) was used in 27 patients with 27 leukoplakia lesions. Postoperative pain was assessed by use of visual analog scale (VAS), and the impact of laser treatment on the quality of life was assessed by the OHIP-14 questionnaire (Croatian version). Control group consisted of the same 27 patients previously treated with 1% topical isotretionin three times a day during the period of one year. No improvement in the size of leukoplakia lesions was observed after treatment with topical isotretinoin. There were significant differences between men and women according to leukoplakia localization, number of laser sessions and VAS (p<0.05). At follow-up after six months and one year, there was no recurrence of lesions. Er:YAG laser is a successful treatment for oral leukoplakia. Topical isotretionin treatment is unsuccessful in patients with oral leukoplakia.

Push-out bond strength of three different calcium silicate-based root-end filling materials after ultrasonic retrograde cavity preparation.

OBJECTIVE: The aim of this study was to evaluate the bond strength of three calcium silicate-based root-end filling materials. MATERIALS AND METHODS: The root canals of 30 single-rooted teeth were endodontically treated; their root ends were resected and root-end cavities were prepared using ultrasonic tip. The teeth were randomly divided into three groups according to the material: (1) Micro-Mega mineral trioxide aggregate (MM-MTA), (2) Biodentine, and (3) TotalFill root repair material (RRM). Push-out test was performed using universal testing machine, and failure mode was analyzed by stereomicroscope. The data were statistically analyzed using Kruskal-Wallis and Man-Whitney post hoc tests. All p values < 0.05 were considered significant. RESULTS: TotalFill RRM exhibited significantly higher bond strength (12.69 MPa) than Biodentine (9.34 MPa, p = 0.023) and MM-MTA (7.89 MPa, p = 0.002). The difference between Biodentine and MM-MTA was not significant (p = 0.447). Mixed failures were the most noted in all three groups. MM-MTA had more adhesive failures than Biodentine and TotalFill, and no cohesive failures, but without statistical significance (p = 0.591). CONCLUSION: The bond strength was the highest for TotalFill RRM. CLINICAL RELEVANCE: In order to provide a persistent apical seal, root-end filling materials should resist dislodgement under static conditions, during function and operative procedures. TotalFill RRM exhibited higher bond strength to dentin than MM-MTA and Biodentine.

Enamel alteration following tooth bleaching and remineralization.

The purpose of this study was to compare the effects of professional tooth whitening agents containing highly concentrated hydrogen peroxide (with and without laser activation), on the enamel surface; and the potential of four different toothpastes to remineralize any alterations. The study was performed on 50 human molars, divided in two groups: treated with Opalescence(®) Boost and Mirawhite(®) Laser Bleaching. Furthermore, each group was divided into five subgroups, a control one and 4 subgroups remineralized with: Mirasensitive(®) hap+, Mirawhite(®) Gelleѐ, GC Tooth Mousse™ and Mirafluor(®) C. The samples were analysed by SEM/3D-SEM-micrographs, SEM/EDX-qualitative analysis and SEM/EDX-semiquantitative analysis. The microphotographs show that both types of bleaching cause alterations: emphasized perikymata, erosions, loss of interprizmatic substance; the laser treatment is more aggressive and loss of integrity of the enamel is determined by shearing off the enamel rods. In all samples undergoing remineralization deposits were observed, those of toothpastes based on calcium phosphate technologies seem to merge with each other and cover almost the entire surface of the enamel. Loss of integrity and minerals were detected only in the line-scans of the sample remineralized with GC Tooth Mousse™. The semiquantitative EDX analysis of individual elements in the surface layer of the enamel indicates that during tooth-bleaching with HP statistically significant loss of Na and Mg occurs, whereas the bleaching in combination with a laser leads to statistically significant loss of Ca and P. The results undoubtedly confirm that teeth whitening procedures lead to enamel alterations. In this context, it must be noted that laser bleaching is more aggressive for dental substances. However, these changes are reversible and can be repaired by application of remineralization toothpastes.

Evaluation of Bone Healing After Osteotomies Prepared With Er:YAG Laser in Contact and Noncontact Modes and Piezosurgery--An Animal Study.

PURPOSE: To analyze the healing of bone tissue treated with Er:YAG laser contact and noncontact modes of and piezosurgery in a rat model using triangular laser profilometry. MATERIALS AND METHODS: Twenty-four 10-week-old adult male Wistar rats were used in the study. Three osteotomies on the medial part of tibia were performed in each animal, 1 in the right tibia and 2 in the left tibia. The osteotomies were performed with a piezoelectric device set at maximal power and the Er:YAG laser in contact mode (power, 7.5 W; pulse energy, 375 mJ; repetition rate, 20 Hz; MSP mode) and noncontact mode (power, 7.5 W; pulse energy, 750 mJ; repetition rate, 10 Hz; QSP mode) with a novel type of circular, digitally controlled handpiece (x-Runner). After surgery, 6 animals were immediately euthanized (group 1), and the others were euthanized after 1 week (group 2, n = 6), 2 weeks (group 3, n = 6), and 3 weeks (group 4, n = 6). Bone healing after osteotomy was analyzed using a 3-dimensional laser scanning technique (ie, laser triangulation profilometry). RESULTS: The volume reduction rates are similar for all 3 techniques (0.2 to 0.25 mm(3) per week). Greater volume reduction of 0.25 mm3 per week was observed for the Er:YAG laser in noncontact mode (x-Runner). After 3 weeks, almost complete healing of the prepared osteotomy was observed. CONCLUSION: Within the limitations of this study, the osteotomies performed by the Er:YAG laser in digitally controlled noncontact mode healed the fastest.

Bone Healing Following Different Types of Osteotomy: Scanning Electron Microscopy (SEM) and Three-Dimensional SEM Analyses.

The aim of the present study was to compare dynamics of the bone healing process after different types of osteotomies. In total, 24 Wistar rats were subjected to different types of osteotomy performed with standard steel bur, piezosurgery, contact, and non-contact Erbium:yttrium-aluminum-garnet (Er:YAG) laser ablation. The animals were randomly divided into four groups, to be euthanized immediately after the procedure, or at 1, 2, or 3 weeks after surgery. The obtained bone samples were analyzed by scanning electron microscopy (SEM). Immediately after surgery, there were significant differences in the appearance of the bone defects, with presence of bone fragments and debris after standard steel bur preparation, compared with the clean smooth walls and relatively sharp edges in all other groups. The initial bone formation in defects prepared by piezosurgery was observed to be the most rapid. After 3 weeks, all bone defects were completely restored; although, differences in the healing pattern were noted, with a modest initial delay in healing after laser preparation. The first stage of the bone healing process was delayed when contact and non-contact Er:YAG laser modes were used and accelerated by piezosurgery; however, the results after 3 weeks demonstrated similar restitution of defects in all tested groups.

[INFLUENCE OF NECK DISSECTION ON THE CORRESPONDING MOTOR AND SENSORY NERVES]. / UTJECAJ DISEKCIJE VRATA NA ODGOVARAJUCE MOTORICKE I OSJETNE ZIVCE.

OBJECTIVE: Radical neck dissection (RND), utilized for treatment of lymph node metastases in patients with head and neck cancers, can result in clinically significant functional disturbance secondary to the corresponding nerve damage. However, there is only limited data relative to post-operative analysis of impact of RND on the cranial and cervical nerves after neck dissection especially regarding the technique used such as electroknife or scalpel. STUDY DESIGN: 48 patients (42 men and 6 women) with intraoral cancer were enrolled. A total of 55 dissections were performed, including 7 patients who received bilateral dissections. Analysis of motor and sensory nerves was conducted seven days and three months later with regard whether electroknife or scalpel was used. RESULTS: The most frequent post-operative loss of motor function was seen in accessory and hypoglossal nerves; within sensory nerves the lingual nerve was most frequently dysfunctional. Permanent diaphragm dysfunction was seen in 15% of investigated patients. CONCLUSION: We might conclude that routine evaluation of sensoneural and motor nerve function of all potentially damaged nerves should be performed after RND, especially regarding diaphragm paralysis. There were no differences in postoperative nerve function of the examined nerves with regard to the technique used (electroknife/scalpel).

Lateral Alveolar Ridge Augmentation with Autogenous Tooth Roots and Staged Implant Placement-5-Year Follow-Up Case Series.

Background/Objectives: Alveolar bone augmentation before implant placement is a safe and effective treatment option for the reconstruction of a deficient alveolar ridge. According to recent research, permanent teeth have been used as bone graft materials, with studies confirming their clinical and histological results. This study aimed to evaluate the efficacy of alveolar ridge augmentation with autogenous tooth roots and staged implant placement, and peri-implant tissue stability in augmented sites. Methods: A total of 20 augmentations with autogenous tooth roots on mandibular alveolar ridges in 15 patients were performed. After 6 months, the ridge width (RWa) and ridge width gain (RWg) were measured. Titanium dental implants were placed in grafted sites and loaded 10 weeks after placement. Clinical parameters (bleeding on probing-BOP; probing depth-PD; mucosal recession-MR; and clinical attachment level-CAL) were assessed 2 months (T1), 3 years (T2), and 5 years (T3) after implant loading. Results: The mean RWa was 6.71 ± 0.74 mm, and the RWg was 3.15 ± 0.54 mm, respectively. No statistically significant differences were observed for clinical parameters (BOP, PD, MR, and CAL) among different time points (p > 0.05). Conclusions: Autogenous tooth roots represent a viable solution for alveolar ridge augmentation and implant placement, providing a stable environment for peri implant tissues.

Evaluation of Different Procedures for Titanium Dental Implant Surface Decontamination-In Vitro Study.

Polymicrobial biofilm removal and decontamination of the implant surface is the most important goal in the treatment of periimplantitis. The aim of this study is to evaluate the efficacy of four different decontamination methods for removing Acinetobacter baumannii and Staphylococcus aureus biofilms in vitro. Seventy-five dental implants were contaminated with a bacterial suspension and randomly divided into five groups (n = 15): the negative control group, which received no treatment; the positive control group, treated with 0.2% chlorhexidine; group 1, treated with a chitosan brush (Labrida BioCleanTM, Labrida AS, Oslo, Norway); group 2, treated with a chitosan brush and 0.2% chlorhexidine; and group 3, treated with a device based on the electrolytic cleaning method (GalvoSurge, GalvoSurge Dental AG, Widnau, Switzerland). The colony-forming unit (CFU) count was used to assess the number of viable bacteria in each sample, and statistical analyses were performed. When compared to the negative control group, all the decontamination methods reduced the CFU count. The electrolytic cleaning method decontaminated the implant surface more effectively than the other three procedures, while the chitosan brush was the least effective. Further research in more realistic settings is required to assess the efficacy of the decontamination procedures described in this study.

Effect of sodium hypochlorite and ethylenediaminotetraacetic acid activated by laser and ultrasonic energy on surface morphology and chemical composition of intracanal dentin.

The aim of the study was to evaluate the structural and chemical changes in intracanal dentin after root canal irrigation with sodium hypochlorite (NaOCl) and ethylenediaminetetraacetic acid (EDTA) using additional activation with a novel Er:YAG Shock Wave-Enhanced Emission Photoacoustic Streaming (SWEEPS), ultrasonic irrigation (UI), and Nd:YAG irradiation. Root canals of extracted human premolars were instrumented with distilled water and distributed into groups according to the irrigation protocol used: Group 1: conventional needle irrigation (CI) with 3% NaOCl; group 2: CI with 15% EDTA; and group 3: CI with NaOCl+EDTA. In group 4, root canals were irrigated with NaOCl+EDTA+NaOCl using the following techniques: CI (group 4A), SWEEPS (group 4B), UI (group 4C). In group 4D, root canals were finally irradiated with Nd:YAG laser. After the irrigation, the intracanal dentin sample was collected and analyzed using spectroscope with a Fourier transformation of infrared spectrum in Attenuated total reflection technique (FTIR-ATR) to calculate apatite/collagen ratio. Scanning electron microscopy (SEM) and energy dispersive x-ray spectrometry (EDS) were used to determine its chemical composition. FTIR-ATR showed no significant difference in the phosphate/amid I ratio between the control and the experimental groups (p > 0.05). SWEEPS and UI of NaOCl+EDTA+NaOCl caused the most pronounced decrease of Ca and P (p < 0.05) value compared to CI and control group, and canal wall erosion. SWEEPS and UI of NaOCl+EDTA+NaOCl caused the most pronounced decrease of Ca and P value and significant canal wall erosion. However, no difference in phosphate/amide ratio was reported among groups. RESEARCH HIGHLIGHTS: SWEEPS and UI of NaOCl+EDTA+NaOCl caused the most pronounced decrease of Ca and P values and significant canal wall erosion. There was no difference in phosphate/amide ratio among the irrigation protocols.

Mechanical Characteristics of Individualized Biodegradable Augmentation Scaffold-In Vitro Pilot Study.

The alveolar ridge reconstruction of vertical and combined bone defects is a non-predictable procedure with varying percentages of success. The greatest challenge for vertical and combined bone augmentation is to maintain mechanical stability of the bone graft; therefore, it is mandatory to provide and preserve space for bone regeneration. The development of biomaterials and 3D printing has enabled the use of polymer scaffolds in the reconstruction of alveolar ridge defects. The aim of this pilot study was to evaluate the mechanical characteristics of an innovative individualized biodegradable polylactic acid (PLA) scaffold, under dynamic conditions, simulating biodegradation and the influence of masticatory forces. After the design and 3D printing of PLA scaffolds, two groups of 27 scaffolds were formed according to the compression testing procedure. The compression tests were performed in occlusal and lateral directions. In each of the two groups, nine subgroups of three scaffolds were formed for different testing periods during in vitro degradation with a total period of 16 weeks. Results showed that biodegradation and load application had no significant influence on mechanical characteristics of tested scaffolds. It can be concluded that simulated masticatory forces and biodegradation do not significantly influence the mechanical characteristics of an individualized biodegradable augmentation scaffold.

Comparison of Three Different Orthodontic Adhesives Bonded to Metallic and Ceramic Brackets: SEM and SEM/EDX Analysis (In Vitro Study).

Objectives: To compare three different orthodontic adhesives (Transbond XT Light Cure Adhesive, Heliosit Orthodontic, Fuji Ortho LC) bonded to two types of orthodontic brackets: ceramic brackets (Fascination Roth 0.22) and metallic brackets (Topic Roth 0.22, Dentaurum). Materials and methods: The study was performed on 18 human teeth (6 for each adhesive). The prepared teeth were divided into three groups according to the examination time. Subsequently, they were observed after 1, 2 and 3 weeks following bonding. After the experimental procedure, the teeth samples were cut in half along the longitudinal axis in the vestibulo-oral direction, fixed with conductive carbon cement, placed in a high-vacuum evaporator and then coated with carbon. One half of each sample was observed under a Field-emission gun scanning electron microscope (FEG-SEM Hitachi SU 8030, Japan), while on the second half of the samples qualitative (X-ray line-scans) and semi-quantitative point X-ray energy dispersive analyses (EDX) were performed with Thermo Noran (USA) NSS System 7, equipped with Ultra Dry detector (30 mm2 window). Results: Transbond XT had an ideal bond with the enamel and the bracket base, with rare presence of microgaps and cracks in the enamel. Heliosit Orthodontic demonstrated a better bond relationship with the bracket base than the enamel, whereas in the latter the presence of microgaps in the bond was observed. The microphotographs of Fuji Ortho LC demonstrated many cracks inside the adhesive, and some of them continued to move forward into the enamel surface. Therefore, an impression of a very solid bond relationship with the enamel exists, with cracks being present in the enamel surface and never at the enamel-adhesive interface. Microgaps also appeared at the bracket-adhesive interface. Conclusion: Transbond XT is a highly filled composite resin and is an ideal orthodontic adhesive in each aspect examined, with an ideal enamel-adhesive and bracket-adhesive interface. Heliosit Orthodontic provides better bracket-adhesive interface compared to the enamel. Fuji Ortho LC as a solid resin-modified GIC provides a better enamel-adhesive interface, compared to the bracket base.

Pink Esthetic Score Around Single-Tooth Implant Crowns After Socket-Shield Technique: A Prospective Cohort Study.

Esthetics is important for any dental implant but crucial for implants in the anterior region. Restorations in this region are demanding, and the goal of re-establishing an attractive smile without revealing differences from the natural teeth is difficult to achieve. The aim of this study was to examine the clinical success of the socket-shield technique regarding soft tissue stability and overall esthetic outcome. Pink esthetic scores (PESs) were collected at two time points (T1: 6 months; T2: 6 years) by three different specialists. This prospective cohort clinical study involved 30 patients (7 women and 23 men) with a mean age of 42.3 years. There were no significant differences in PES values assessed by the oral surgeon and prosthodontist (P > .05) at either of the assigned time points. The periodontist found differences in PES values between T1 and T2 (P < .05), but they were modest in value. Analyses of each individual variable at given time intervals revealed significant differences in the shape of the distal papillae (χ2 = 6.182; P < .05) and soft tissue margin level (χ2 = 6.507; P < .05). The final results suggest that the socket-shield technique is promising for implant placement in the esthetic zone.

Evaluation of the Photoactivation Effect of 3% Hydrogen Peroxide in the Disinfection of Dental Implants: In Vitro Study.

Photoactivation of 3% hydrogen peroxide with a 445 nm diode laser represents a relatively new, insufficiently researched antimicrobial method in the treatment of peri-implantitis. The purpose of this work is to evaluate the effect of photoactivation of 3% hydrogen peroxide with a 445 nm diode laser, and to compare the obtained results with 0.2% chlorhexidine treatment and 3% hydrogen peroxide treatment without photoactivation, in vitro, on the surface of dental implants contaminated with S. aureus and C. albicans biofilms. Previously, 80 infected titanium implants with S. aureus and C. albicans cultures were divided into four groups: G1-negative control (no treatment), G2-positive control (0.2% chlorhexidine), G3 (3% hydrogen peroxide), and G4 (photoactivated 3% hydrogen peroxide). The number of viable microbes in each sample was determined by the colony forming unit (CFU) count. The results were statistically processed and analyzed, showing a statistically significant difference across all groups compared to the negative control (G1), and the absence of a statistically significant difference between groups G1-G3. The new antimicrobial treatment, according to the results, could be worthy of further analysis and research.