Survival analysis of dental implants placed in horizontally severely resorbed maxillae after reconstruction with xenogeneic graft: a case series

PURPOSE

To evaluate the survival rates of dental implants with a hybrid macrostructure and the surface biomimetically coated with nanohydroxyapatite, placed in horizontally atrophic maxillae previously submitted to the guided bone regeneration (GBR) procedure, associated with the use of a deproteinized bovine bone graft (DBB).

METHODS

Twenty-five patients who received 196 implants were involved in this study. First, these patients were submitted to GBR procedures and maxillary sinus lift, where DBB was used as the grafting material. The dental implants were placed after a minimum period of 6 months of the grafting procedures. The patients were followed up every six months and clinical/radiographic examinations were performed to assess the implants, using the following indicators as a reference: (1) Absence of mobility; (2) Absence of pain. Data about the age, surgery time, smoking status, implant size, and time between the grafting procedure and implant placement were correlated with implant failures.

RESULTS

Twelve implants failed, generating a survival rate of 94.23%. None of the variables analysed correlated with the implant failures.

CONCLUSION

Implants with a hybrid macrostructure and surface biomimetically coated with nanohydroxyapatite present good survival rates in horizontally atrophic maxillae grafted with DBB.

Effect of photobiomodulation with different wavelengths on periodontal repair in non-hyperglycemic and hyperglycemic rats

BACKGROUND

Hyperglycemic conditions is associated with more severe periodontitis and poorer outcomes after nonsurgical periodontal treatment (NPT). Then, these patients are candidates for adjunctive therapy associated with NPT. This study evaluates the effect of photobiomodulation (PBMT) at different wavelengths on periodontal repair in non-hyperglycemic/hyperglycemic animals.

MATERIALS AND METHODS

Sixty-four rats were submitted to induction of periodontitis by ligatures. Hyperglycemia was induced in half of these animals, whereas the other half remained non-hyperglycemic. The animals were subdivided into 4 groups according to the PBMT protocol applied at the time of ligature removal (n = 8): CTR: Without PBMT; IRL: PBMT with infrared laser (808 nm); RL: PBMT with red laser (660 nm); and RL-IRL: PBMT with red (660 nm) and infrared laser (808 nm). After a period of 7 days, the animals were euthanized. The parameters assessed by microtomography were the bone volume relative to total tissue volume (BV/TV%), distance from the cemento-enamel junction to the top of the bone crest (CEJ-CB), trabecular thickness, space between trabeculae, and number of trabeculae. Additionally, the percentage of inflammatory cells, blood vessels, and connective tissue matrix were assessed by histomorphometric analysis.

RESULTS

PBMT reduced bone loss and increased trabecular density in hyperglycemic animals (p < .05), with RL being more effective in reducing linear bone loss (CEJ-CB), whereas RL-IRL was more effective in maintaining BV/TV%. PBMT reduced blood vessels and increased the connective tissue component in hyperglycemic animals (p < .05). RL-IRL reduced inflammatory cells regardless of the systemic condition of the animal (p < .05).

CONCLUSION

PBMT (RL, RL-IRL) improves the repair of periodontal tissues in hyperglycemic animals.

Efficacy of analgesia promoted by lidocaine and articaine in third molar extraction surgery. A split-mouth, randomized, controlled trial

PURPOSE

The aim of this study was to compare the analgesic efficacy of 4% articaine associated with epinephrine (1:100,000), and 2% lidocaine associated with epinephrine (1:100,000) in third molar extraction surgery.

METHODS

Sixty patients who underwent surgeries to extract upper and lower third molars were included in this split-mouth, double-blind, randomized, controlled trial. The groups in this study were divided according to the anesthetic solution used to provide local anesthesia during extraction of upper and lower third molars: (1) 4% articaine associated with epinephrine (1:100,000); (2) 2% lidocaine associated with epinephrine (1:100,000). The time to the beginning and end of the sensation of analgesia, pain sensation according to the VAS scale, and number of anesthetic tubes necessary for supplementation were analyzed.

RESULTS

It was found that the onset time for analgesia was shorter on the side anesthetized with articaine compared to the side anesthetized with lidocaine (122.1 ± 52.90 s vs. 144.5 ± 68.85 s) (p < 0.05). In addition, the number of tubes used for anesthetic supplementation was also reduced on the articaine side compared to the lidocaine side (0.26 ± 0.48 vs. 0.50 ± 0.75) (p < 0.05). There were no differences between the anesthetic solutions in the other evaluated parameters.

CONCLUSION

It can be concluded that the use of 4% articaine associated with epinephrine (1:100,000) reduced the time of onset of analgesia and the necessity for anesthetic supplementation in third molar extraction surgeries compared to the use of 2% lidocaine associated with epinephrine (1:100,000).

Wound-healing agents for palatal donor area: A network meta-analysis

BACKGROUND

The aim of this systematic review and network meta-analysis (NMA) was to assess the efficacy of different wound-healing agents for palatal donor area management after soft tissue graft harvesting.

METHODS

Electronic searches in six databases were conducted for publications up to October 2023. Studies with data from patients undergoing therapeutic approaches using agents for palatal healing after gingival graft harvesting were included. Data about postoperative pain, wound-healing and postoperative complications reported for each agent were extracted. Three different tools were used for the risk of bias within studies evaluation (Murad tool for case series and case report, RoB 2.0 tool for randomized studies and ROBINS-I tool for non-randomized studies). A Bayesian random effects NMA was conducted for postoperative pain levels and wound healing.

RESULTS

Eighty-four publications were included in the systematic review (qualitative analysis), with 14 of these subjected to NMA (quantitative analysis). The summarized results from the qualitative and quantitative analysis showed that all wound-healing agents evaluated promoted better pain control and wound healing compared to spontaneous healing and hemostatic sponges alone. The NMA outcomes reveal that leucocyte- and platelet-rich fibrin (L-PRF) was the most effective agent in reducing postoperative pain in all analyzed periods. Moreover, the L-PRF seems to accelerate wound healing and reduce postoperative complications compared to other agents.

CONCLUSION

In conclusion, the L-PRF was the most effective agent in reducing postoperative pain, accelerating wound healing and reducing postoperative complications after harvesting soft tissue grafts from the palatal area.

Comparison of different dual-wavelength photobiomodulation protocols application in third molar extractions. A split-mouth randomized controlled trial

OBJECTIVE

To compare the use of PBMT in the soft tissue and bone healing after third molar extraction using the dual-wavelength laser directly into the post-extraction alveoli (PBMT-I), or PBMT with a red laser directly into the alveoli and with an infrared laser externally on the patient's face (PBMT-IE).

METHODS

Twenty patients underwent extraction of four third molars were involved in this split-mouth double-blind randomized controlled trial. The Post-extraction alveoli were treated with the following protocols: PBMT-IE: Application of a red laser directly into the alveolus, and infrared laser irradiation transcutaneously and PBMT-I: Application of dual-wavelength laser intraorally. Patients were clinically evaluated 3, 7, 14, 30, and 90 days after the surgical procedure. The analyses in this study were divided into qualitative (centered on the patient's report and on the evaluators' analysis), and quantitative analyses (measurement of the vertical and horizontal dimensions of the face with the objective of measuring post-surgical edema and radiographic analyses for evaluation of the density and structure of the newly formed bone).

RESULTS

A progressive improvement was observed in all parameters evaluated in this study, however, this improvement was time dependent, with no distinct effect observed between the PBMT treatments applied.

CONCLUSION

The different dual-wavelength PBMT protocols induced a similar postoperative clinical course in third molar extraction surgeries, with a reduced occurrence of complications and a good healing pattern of hard and soft tissues.

Green tea and hyaluronic acid gel enhance fibroblast activation and improves the gingival healing post-third molar extraction

This study evaluates the effects of a green tea (Camellia sinensis) and hyaluronic acid gel on fibroblast activity and alveolar bone repair following third molar extractions. By examining the gene expression related to cell survival, proliferation, and angiogenesis, the study bridges in vitro findings with clinical outcomes in a split-mouth randomized trial. Human fibroblasts were exposed to the treatment gel, analysing gene expression through RT-qPCR. Twenty participants undergoing bilateral third molar extractions received the test gel on one side and a placebo on the other. Assessments included patient-reported outcomes, professional evaluations, and radiographic analyses at multiple postoperative intervals. The test gel significantly enhanced AKT, CDKs, and VEGF gene expressions, indicating a positive effect on angiogenesis and cell proliferation. Clinically, it resulted in reduced exudate, swelling, and secondary interventions, with radiographs showing improved alveolar bone density after 90 days. The green tea and hyaluronic acid gel significantly improves soft tissue and bone healing post-extraction, offering a promising adjunctive therapy for enhancing postoperative recovery. This gel represents a novel adjuvant treatment option for facilitating improved healing outcomes after third molar extractions, highlighting its potential utility in clinical dental practice.

Supraphysiologic Testosterone Administration Impairs Late Osseointegration in Male Rats

PURPOSE

To evaluate the effect of supraphysiologic administration of testosterone in an early and late model of implant osseointegration in rat tibiae.

MATERIALS AND METHODS

A total of 40 rats were randomly allocated into four groups (n = 10/ group), which were divided according to the type of experiment and time of osseointegration: (1) vehicle (14 days), (2) testosterone (14 days), (3) vehicle (42 days), and (4) testosterone (42 days). Testosterone cypionate (7.5 mg/kg) administration started 4 weeks before implant placement, and the injections were performed daily until euthanasia. Machined-surface titanium implants (2.2 mm in diameter and 4 mm high) were placed bilaterally in the tibia of animals 28 days after the first testosterone injection. At days 14 and 42 after implant placement, euthanasia was performed and the tibiae were harvested to perform biomechanical evaluation and histomorphometric analysis of bone-to-implant contact (BIC%) and bone between the threads (BBT%).

RESULTS

There was no statistical difference in the removal torque of the implants between the groups treated with the vehicle (control group) or testosterone (P > .05). At 14 days of osseointegration, the BIC% and BBT% did not differ between vehicle or testosterone groups (P > .05), while at 42 days, both the BIC% and BBT% were significantly reduced by testosterone compared to the vehicle group (P < .05).

CONCLUSIONS

Testosterone cypionate in supraphysiologic dose impaired late-phase osseointegration in rat tibiae.

Assessing bone formation on hydrophilic and hydrophobic implant surfaces in a murine model treated with bisphosphonates

OBJECTIVE

To evaluate the osseointegration of implants with hydrophobic (HFB) and hydrophilic (HFL) surfaces in a murine model of high-dose bisphosphonates (BPs).

MATERIALS AND METHODS

Sixty-four rats were randomly allocated into four groups: control group with HFB implants (CG-HFB), control group with HFL implants (CG-HFL), BP group with HFB implants (BP-HFB), and BP group with HFL implants (BP-HFL). Animals were euthanized after 15 and 45 days (n=8). The dependent variables assessed were the removal torque (biomechanical analysis), the bone volume around the implants (%BV/TV) (microtomographic analysis), the bone-implant contact (%BIC), the bone between the threads (%BBT) (histomorphometric analysis), and the expression of bone metabolism markers (immunohistochemistry analysis).

RESULTS

The CG-HFL and BP-HFL groups presented higher removal torque than the CG-HFB and BP-HFB implants. The %BIC of the CG-HFL surfaces was slightly higher than that of the CG-HFB implants. The BP-HFB and BP-HFL groups presented a higher %BIC than that of the CG-HFB and CG-HFL groups (p<0.001). BP therapy also increased the %BBT at both implant surfaces. Higher levels of ALP were observed in the matrix region of bone tissue on the HFL surfaces than on the HFB surfaces.

CONCLUSION

Both surfaces enable osseointegration in rats under BP therapy.

CLINICAL RELEVANCE

The study demonstrates that hydrophobic (HFB) and hydrophilic (HFL) implant surfaces can promote osseointegration in rats undergoing bisphosphonate therapy. The HFL surfaces exhibited improved biomechanical performance, higher bone-implant contact, and increased bone volume, suggesting their potential clinical relevance for implant success in individuals on bisphosphonate treatment.

Fluoride-modified implant surfaces improves osseointegration in the tibias of rats with induced diabetes

This study evaluated the influence of a fluoride-modified titanium surface on osseointegration in rats with induced diabetes. One hundred and eighty rats were randomly allocated into 3 groups with 60 animals each: Control group (C): Animals without diabetes; Diabetes Group (D): Animals with uncontrolled induced diabetes; Controlled Diabetes Group (CD): Animals with diabetes induced controlled by the insulin administration. Diabetes was induced by streptozotocin injection. Each animal received 2 implants in the proximal tibial metaphysis, one with the machined surface (M) and the other one with a fluoride-modified titanium surface (F), after 4 weeks of induction of diabetes. The animals were submitted to euthanasia 2, 4, and 6 weeks after the implant placement (n = 20 animals/group). The osseointegration was evaluated by the implant removal torque test and the histometric analysis of the non-decalcified histological sections: 1) Contact bone/implant (%BIC); 2) Bone tissue area between implant threads (%BBT). Implants with F surface showed a higher removal torque than implants with surface M in all groups. There was no difference in %BIC between the groups regardless of the surface used. The F surface showed a tendency to present higher %BBT values for the 3 evaluation periods in the D group. The fluoride-modified implant surface has no impact on the %BIC and %BBT. However, the fluoride-modified implant surface increases the locking of the implants with the bone. The hyperglycemia was associated with lower removal torque values despite the surfaces of the implant used.

Effect of a gel containing green tea extract and hyaluronic acid on palate pain scores and wound healing after free gingival graft: a quasi-randomized controlled clinical trial

OBJECTIVES

The aim of this study was to evaluate the effect of a gel containing green tea extract and hyaluronic acid (HA) on pain scores and wound healing in donor sites after free gingival graft (FGG).

MATERIALS AND METHODS

Forty-two patients requiring FGG were included in three groups: (1) control group (n = 14), no material was placed in the donor area; only the clot was kept in position by sutures; (2) placebo group (n = 14), vehicle gel applied 3 times a day for 7 days; and (3) test group (n = 14), gel containing green tea extract and HA applied 3 times a day for 7 days. The wound size by clinical measurement (WS-CM) and photographic image (WS-PI), complete wound epithelialization (CWE), and palatal mucosa color were evaluated after 3 days and 1, 2, and 4 weeks postoperatively. The visual analog scale (VAS) for pain and analgesic consumption were used to assess participant's perception in the same postoperative periods.

RESULTS

A similar progressive reduction in the wound size, associated with an improvement in the color pattern, was observed in all groups (p > 0.05). No significant differences were found for CWE and pain assessment between the examined groups (p > 0.05).

CONCLUSION

The gel containing green tea extract and HA application in palatal wounds after FGG removal does not provide clinical healing benefits using this investigated protocol.

CLINICAL RELEVANCE

This is the first clinical study evaluating the effect of gel containing green tea extract and HA on the palate postoperative pain control and wound healing after FGG.

TRIAL REGISTRATION

http://clinicaltrials.gov : NCT05270161.

Fresh-frozen allogeneic bone blocks grafts for alveolar ridge augmentation: Biological and clinical aspects

The possibilities for oral bone regeneration procedures vary depending on the type of bone defect to be treated, which in turn dictate the type of graft to be used. Atrophic alveolar ridges are non-contained defects and pose a challenging defect morphology for bone regeneration/augmentation. Successful results are regularly obtained with the use of particulate grafts in combination with barrier membranes. In cases of very narrow ridges with need of larger amount of bone augmentation, block grafts are often used. Fresh-frozen allogeneic bone block grafts have been proposed as an alternative to autogenous (AT) bone blocks. Based on a systematic appraisal of pre-clinical in vivo studies and clinical trials including a direct comparison of fresh-frozen bone (FFB) blocks versus AT bone blocks it can be concluded that a FFB block graft: (a) cannot be considered as a reliable replacement of a AT bone block, and (b) should only be considered in cases where the amount of necessary augmentation-in a lateral direction-is relatively limited, so that the main portion of the body of the implant lies within the inner (i.e., the vital) aspect of the block.

Effect of Antibiotic Prophylaxis on Early Loss of Implants Installed by Unexperienced Operators

Routine use of antibiotics for dental implant installation is widely applied in dental practice to prevent postoperative infection and implant loss. However, the effectiveness and necessity of such protocols have not been consensual in the literature. This study aimed to evaluate the effect of antibiotic prophylaxis on survival of dental implants placed in clinically healthy patients by unexperienced operators. A double-blind, randomized, placebo-controlled trial was conducted. Ninety patients who received between 2 and 4 dental implants by unexperienced operators were enrolled in this study. Patients were randomly allocated in 2 groups. For the antibiotic group (n = 47), patients received 1 g of preoperative amoxicillin; in the placebo group (n = 43), patients received preoperative placebo administration. Each patient was evaluated preoperatively, 2 days, and 7 days postoperatively. Factors evaluated were mouth opening amplitude, assessment of referred pain through a visual analogue scale, and characteristic signs of infection (presence of fistula, ulceration in the surgical wound, tissue necrosis at the edges of the wound, dehiscence of the surgical flap, and presence of purulent exudate in the surgical wound). Implant survival was evaluated until 90 days postsurgical procedure. Results showed that there were no statistically significant differences in postoperative healing, swelling, and pain. However, more loss of dental implants was observed in the placebo group (14.9% vs 2.3%). Use of antibiotic prophylaxis reduced implant loss that was previously placed by unexperienced operators.

Computer-Aided Design/Computer-Aided Manufacturing of Customized Abutment for Rehabilitating a Malpositioned Implant Using Digital Flow: A Case Report

This study presented a rehabilitation option for malpositioned implants; this involved obtaining their position and inclination through intraoral scanning, and producing a customized abutment with CAD/CAM technology. The patient in this case report presented a root fracture in tooth 21 and was subjected to extraction, implant installation, and immediate provisional prosthesis. The implant was installed with a distal inclination due to anatomical limitations. After osseointegration, an intraoral scanning transfer provided a digital model (file extension .stl), which reproduced the implant's position and inclination. Then, the file was sent so that a customized abutment (CAD/CAM) could be manufactured, promoting the final rehabilitation of the case; this allowed for good hygiene, load distribution in the dynamic interocclusal relationship, and favorable esthetics, whereas many would otherwise recommend implant removal. The result presented lower costs, a shorter time frame, and a lower morbidity for the patient.

Advanced platelet-rich-fibrin (A-PRF +) has no additional effect on the healing of post-extraction sockets of upper third molars. A split mouth randomized clinical trial

PURPOSE

This study evaluated  the effects of advanced platelet-rich fibrin (A-PRF +) on the healing of upper third molar post-extraction sockets.

METHODS

Sixteen patients who underwent extractions of the upper third molars (18 and 28) were included in this randomized split-mouth study. The alveoli on the test side were filled with A-PRF + , while the control side was maintained with blood clot. The side that received treatment was randomly defined. Alveolar bone regeneration was evaluated by CBCT scans to assess healing stage, bone density, and fractal analysis 1 week and 90 days post-extraction. Additionally, pain, edema, bleeding, and soft tissue alveolar repair were evaluated by clinical analyses 3, 7, 14, 30, and 90 days after the surgical procedure using a visual analog scale.

RESULTS

There were no clinical differences regarding treatments in any experimental period. In the tomographic evaluation, at 7 days, the alveoli treated with A-PRF + presented a suggestive sign of higher bone density than the control alveoli, which was not confirmed 90 days after the surgical procedure.

CONCLUSION

Thus, the use of A-PRF + does not demonstrate a clinical advantage in the repair of post-extraction sockets of upper third molars.

Mechanical Behavior of One-Piece and Two-Piece Tapered Prosthetic Abutments with 11.5 and 16 Degrees

The objective of this study is to examine the mechanical behavior of two-piece abutments (Morse taper with 16° internal angulation and Morse taper with 11.5° internal angulation) before and after cyclic fatigue testing, following ISO 14801:2016 guidelines. The specimens were divided into three groups: a modified Morse taper with a taper angle of 16° (GM group), a conventional Morse taper (taper angle of 11.5° deg) with a two-piece (CMt group), and one-piece abutments (CMo group). Each experimental group was formed by ten implants and ten abutments (n = 10) for a total of 30 specimens (n = 30). The abutments were tightened and loosened, and a fatigue test was applied with 15 Hz and 5 × 10⁶ cycles. Subsequently, the abutments were loosened, and a pull-out test was performed on the CMt group. Finite element analysis (FEA) was conducted on stress concentration regions. The statistical analysis of the loosening test was performed using two-way ANOVA and Tukey's tests (p < 0.05) to compare screw loosening within each group and between the groups with and without mechanical fatigue. Significant differences were found among the three groups in the loosening test when analyzing the values with and without fatigue (p < 0.001) within each group. When the groups were compared with each other, there was also a significant difference between them (p < 0.001), except between groups GM and CMt without fatigue (p = 0.840). In the pull-out test of the CMt group, the sample exhibited frictional locking only after fatigue (mean = 94.2 N). The FEA demonstrated a varied stress distribution in all groups. The stress was found to be more concentrated in the upper third and middle third regions of the implant, as well as in the opposite region of the load application for all three groups. Although the CMo group showed lower rates of loosening, it displayed a poorer stress distribution in comparison to the GM and CMt groups. On the other hand, the CMt group exhibited a satisfactory frictional lock after undergoing the fatigue tests.

Effects of red and infrared laser on post extraction socket repair in rats subjected to alendronate therapy

This study evaluated the effect of photobiomodulation therapy (PBMT) with a red or infrared laser on the repair of post extraction sockets in rats administered alendronate (ALN). Forty male rats were randomly allocated into four groups: Control Group (CTR): subcutaneous administration of saline solution throughout the experimental period; Alendronate Group (ALN): subcutaneous administration of alendronate during the entire experimental period; Alendronate/Red Laser Group (ALN/RL): administration of ALN and irradiation with a GaAlAs laser (λ 660 nm); and Alendronate/Infrared Laser Group (ALN/IRL): administration of ALN and irradiation with a GaAlAs laser (λ 830 nm). The first lower molars were extracted 60 days after the beginning of the administration of the drugs. The PBMT was applied after tooth extraction (7 sessions with intervals of 48 hours between sessions). Thirty days after tooth extraction, the animals were euthanized. Micro-CT and histometric analysis were performed to assess the bone healing and soft tissue repair of the tooth socket. The ALN group presented with more bone than the CTR; however, most of this bone was necrotic. ALN does not affect the bone microarchitecture. On the other hand, PBMT with IRL enhances the bone density due to the increase in the number and reduction in the spacing of the trabeculae. The amount of vital bone and connective tissue matrix was higher in the ALN/RL and ALN/IRL groups than in the ALN and CTR groups. PBMT enhanced the healing of the post extraction sockets in rats subjected to ALN administration. Furthermore, IRL improved the new bone microarchitecture.

Evaluation of hydrophilic surface osseointegration in low-density bone: Preclinical study in rabbits

The aim of this study was to evaluate the osseointegration of a hydrophilic surface (blasting + acid etching + immersion in isotonic solution) in comparison with that of a control surface (blasting + acid etching) using an experimental model of low-density bone. To perform the study, 24 rabbits were submitted to the installation of 4 implants in the iliac bone bilaterally: 2 implants with a control surface and 2 implants with a hydrophilic surface. The rabbits were euthanized at 2, 4, and 8 weeks after implant installation. After euthanasia, one implant from each surface was used to perform the removal torque analysis, and the other implant was used for the execution of non-decalcified histological sections and evaluation of the bone implant contact (% BIC) as well as the fraction of bone tissue area between the implant threads (% BBT). The implants with a hydrophilic surface presented higher %BIC (42.92 ± 2.85% vs. 29.49 ± 10.27%) and % BBT (34.32 ± 8.52% vs. 23.20 ± 6.75%) (p < 0.05) in the 2-week period. Furthermore, the hydrophilic surface presented higher removal torque in the 8-week period (76.13 ± 16.00 Ncm2 vs. 52.77 ± 13.49 Ncm2) (p<0.05). Implants with a hydrophilic surface exhibited acceleration in the process of osseointegration, culminating in greater secondary stability in low-density bone than in implants with a control surface.

Laser-Modified Ti Surface Improves Paracrine Osteogenesis by Modulating the Expression of DKK1 in Osteoblasts

Titanium surface modifications are widely used to modulate cellular behavior by recognition of topographical cues. However, how those modifications affect the expression of mediators that will influence neighboring cells is still elusive. This study aimed to evaluate the effects of conditioned media from osteoblasts cultured on laser-modified titanium surfaces on the differentiation of bone marrow cells in a paracrine manner and to analyze the expression of Wnt pathway inhibitors. Mice calvarial osteoblasts were seeded on polished (P) and Yb:YAG laser-irradiated (L) Ti surfaces. Osteoblast culture media were collected and filtered on alternate days to stimulate mice BMCs. Resazurin assay was performed every other day for 20 days to check BMC viability and proliferation. After 7 and 14 days of BMCs maintained with osteoblasts P and L-conditioned media, alkaline phosphatase activity, Alizarin Red staining, and RT-qPCR were performed. ELISA of conditioned media was conducted to investigate the expression of Wnt inhibitors Dickkopf-1 (DKK1) and Sclerostin (SOST). BMCs showed increased mineralized nodule formation and alkaline phosphatase activity. The L-conditioned media enhanced the BMC mRNA expression of bone-related markers Bglap, Alpl, and Sp7. L-conditioned media decreased the expression of DKK1 compared with P-conditioned media. The contact of osteoblasts with Yb:YAG laser-modified Ti surfaces induces the regulation of the expression of mediators that affect the osteoblastic differentiation of neighboring cells. DKK1 is among these regulated mediators.

Digital planning and guided dual technique in esthetic crown lengthening: a randomized controlled clinical trial

OBJECTIVES

The present study aimed to compare the guided dual technique with the conventional technique in esthetic crown lengthening (ECL).

MATERIALS AND METHODS

The trial registration number is NCT04922086. Twenty-four participants diagnosed with altered passive eruption (APE) type I subcategory B were selected and allocated into two groups. In the control group (n = 12), the ECL procedure was planned by clinical examination and transgingival probing; in the test group (n = 12), the ECL procedure was carried out using digital planning and a double guide. Clinical parameters were assessed at baseline, immediately after the intervention (IAI), and at 4, 8, and 12 months of follow-up.

RESULTS

The clinical crown length (CCL) mean at baseline was 8.09 mm (± 0.77) and increased significantly to 9.92 mm (± 0.62) IAI, with minimal significant reduction after 12 months (9.47 mm [± 0.60]) in the control group. Similarly, in the test group, the mean CCL at baseline was 8.04 mm (± 0.69) and increased significantly to 9.94 mm (± 0.57) IAI, with minimal reduction after 12 months (9.35 mm [± 0.80]). No differences were found between the mean CCL determined in the digital planning and after 12 months. No correlation was found between gingival thickness and gingival margin stability. High esthetic satisfaction was demonstrated by participants/specialists without differences between groups.

CONCLUSIONS

In conclusion, the guided dual technique was as effective as the conventional technique for treatment of APE, with stable results after 12 months of follow-up.

CLINICAL RELEVANCE

The guided dual technique aims to transfer both the gingival and bone resection planned position to facilitate the ECL surgical procedure and increase treatment predictability.

Osseointegration of implants with superhydrophilic surfaces in rats with high serum levels of nicotine

This study aimed to evaluate the effect of nicotine administration on the osseointegration of a superhydrophilic implants surface on rat tibiae. Thirty-two rats were used and divided into 2 groups according to the administration or not of nicotine: HH - Installation of implants with superhydrophilic surfaces in healthy animals; and HN - Installation of implants with superhydrophilic surfaces in animals subjected to nicotine administration. The animals were euthanized 15 and 45 days after implant placement (n = 8). Osseointegration was assessed by means of biomechanical analyses (removal torque), microcomputed tomography (volume of bone around the implants- %BV/TV), and histomorphometry (bone-implant contact -%BIC and the bone area between implant threads -%BBT). The animals subject to the nicotine administration presented lower removal torque than the control animals at the 45-day period (21.88 ± 2.80 Ncm vs. 17.88 ± 2.10 Ncm). The implants placed in the control rats presented higher %BIC (54.26 ± 6.59% vs. 39.25 ± 4.46%) and %BBT (50.57 ± 5.28% vs. 32.25 ± 5.24%) than the implants placed in nicotine animals at 15-day period. The nicotine administration reduces the osseointegration at 15 days, however, the superhydrophilic surface equalized the osseointegration in nicotine-exposed animals compared with healthy animals after 45 days of implant placement.

Implants with hydrophilic surfaces equalize the osseointegration of implants in normo- and hyperglycaemic rats

The purpose of this study was to evaluate the effect of a surface modified by blasting and acid attack and maintained in an isotonic solution compared to a machined surface on osseointegration in normo- and hyperglycaemic animals. Sixty-four animals were allocated into 4 groups with 16 animals each, and they were subdivided into two experimental periods (15 and 45 days), with 8 animals in each group. The groups were divided according to the type of implant that was installed in the animals' tibia and the animals' systemic condition: CM - Machined implants placed in Healthy animals; CH - Hydrophilic implants placed in Healthy animals, HM - Machined implants placed in animals with hyperglycaemia; HH- Hydrophilic implants installed in animals with hyperglycaemia. The following analyses were performed: biomechanical (removal torque), microtomographic (evaluation of the bone volume around the implants- BV/TV), and histomorphometric (evaluation of bone-implant contact BIC% and of the bone formation area between the threads BBT%). It was found that the implants with hydrophilic surfaces presented higher removal torques and quantities of BV/TV% and higher BIC% and BBT% values in normo- and hyperglycaemic animals. The results of this study indicated that the hydrophilic surface accelerates the osseointegration process (~ 15% BIC/BBT at 15-day period), especially in animals with hyperglycaemia. The hydrophilic surface equaled the osseointegration between normo- and hyperglycaemic animals, reversing the negative potential of hyperglycaemia on the osseointegration process.

Analysis of the biocompatibility of a biocelulose and a poly L- lactic acid membrane

The use of selective barriers as resorbable membranes has become a routine clinical procedure for guided bone regeneration. Therefore, the production of membranes with a low inflammatory potential during their resorption process has become the goal of a considerable number of researches. Aim: The purpose of the present study was to evaluate the biocompatibility of poly (L- lactic acid) (PLLA) and biocelulose membranes (BC) inserted in the subcutaneous tissue on the dorsum of rats. Methods: Fifteen animals underwent surgical procedures for the insertion of 4 types of membranes: COL (Collagen membrane) – Control Group; BC (Biocellulose membrane); BCAg (Biocellulose membrane impregnated with Silver); PLLA (Poly (L-lactic acid) membrane). All membrane types were inserted into each animal. Animals were euthanized after 3, 7, and 15 days of the surgical procedure. Descriptive histological analyses were carried out to investigate host tissue reaction to membrane presence by assessing the anti-inflammatory process composition associated with the membrane resorption and the presence of foreign-body reaction or encapsulation. Results: The BC membranes showed a higher degree of inflammation and poor pattern of integration with the surrounding tissues than the PLLA and COL membranes. Conclusion: The PLLA and COL membranes present better biocompatibility than the BC membranes.

Hookah Smoking among Brazilian University Students: An Exploratory Survey on the Prevalence and Perceptions of Addiction and its Harmfulness

Background

This study aimed to determine the prevalence, beliefs, attitudes, and perceptions of hookah use in a population of undergraduate students at a large public university in Brazil.

Methods

The sample consisted of 1348 undergraduate students aged over 18-year-old. They completed structured questionnaires on demographic information and close-ended questions on the past and current experiences of smoking hookah. The data underwent descriptive analysis and binary logistic regression.

Findings

Finally, 1298 valid survey forms were obtained from printed and digital questionnaires. More than half (53.9%) of participants reported having tried hookah at least once, however, only 10.8% reported they had experienced it within the last 30 days. The majority of the studied population presented acceptable beliefs about the harmfulness and addictive capacity of hookah smoking. However, when comparing the perceptions of those who had smoked and those who had never smoked hookah, and also, the perceptions of users and non-users, significant differences were observed. Students who were users or had already tried hookah showed a tendency to underestimate the deleterious effects of this type of smoking.

Conclusion

It could be concluded that hookah smoking was common among Brazilian university students. In addition, preoccupying misperceptions of hookah's harmfulness and addictive capacity were found. The results showed that the epidemic of hookah smoking, especially among young people, has spread far beyond the Arab world and the Persians. Accordingly, preventive measures must be taken if this population is to be protected from addiction and other serious health problems.

Comparison of the osseointegration of implants placed in areas grafted with HA/TCP and native bone

This study evaluated the osseointegration of implants in areas grafted with biphasic ceramic based on hydroxyapatite/β-tricalcium phosphate (HA/TCP) and in native bone (NB). Twenty-eight rats were randomly assigned into two groups of 14 animals each: HA/TCP group: implants installed in areas grafted with HA/TCP and NB group: implants installed in areas of native bone. Bone defects were made in both tibiae of the rats belonging to the HA/TCP group and then filled with this bone substitute. After 60 days, the rats were submitted to surgical procedures for implant placement in grafted areas in both tibiae in the HA/TCP group while the implants were installed directly in native bone in the NB group. The animals were euthanized 15 and 45 days, respectively, after the implant placement. Biomechanical (removal torque), microtomographic (volume of mineralized tissues around the implants), and histomorphometric (Bone-Implant contact-%BIC and bone area between the implant threads-%BBT) analyzes were conducted to assess the osseointegration process. The HA/TCP group showed lower values of removal torque, volume of mineralized tissue around the implants, lower %BIC, and %BBT compared to the NB group in both experimental periods. Osseointegration of implants placed in grafted areas with HA/TCP was lower compared to the osseointegration observed in native bone areas.

Digital Smile Design and mock-up technique in esthetic crown lengthening: 2-year follow-up of six cases

The present case series aimed to evaluate the use of a Digital Smile Design (DSD) and mock-up technique for esthetic crown lengthening (ECL) surgery in six clinical cases with a 2-year follow-up. Six nonsmoker patients (five females, one male; aged 22 to 32 years), periodontally and systemically healthy, with inadequate tooth width/height ratio proportions associated with a gingival misalignment in the anterior maxilla were included. The DSDs were created using PowerPoint for all patients to evaluate gingival level and tooth form/contour. A wax-up and mock-up were created based on the DSD measurements. ECL surgeries were performed in all cases using the mock-up technique to determine the final gingival margin position and the amount of bone resection needed. A mock-up to bone crest distance of 3 mm was obtained in all cases. Using patient photographs, comparisons were made between the dental crown length (DCL) measurements obtained before the surgical procedure (baseline; T0), on the DSD template immediately postoperatively (IPO; T1), and at the 2-year follow-up (T2). A DCL augmentation of 1.16 ± 0.68 mm was obtained at T1, with an augmentation of 1.03 ± 0.73 mm at T2. Moreover, a minimal difference of 0.34 ± 0.74 mm between the DCL planned in the DSD template and the DCL obtained IPO was observed. In conclusion, the ECL procedure based on the DSD concept and mock-up technique proposed in this cases series was a predictable protocol for smile disharmony treatment in all the patients.