The effects of sodium alendronate on socket healing after tooth extraction: a systematic review of animal studies.

The aim of this systematic review was to answer the following question: "Does alendronate, a nitrogen-containing bisphosphonate, improve or impair alveolar socket healing after tooth extraction in animal models"? To this end, a systematic review of the literature was carried out in PubMed, Scopus, LILACS, Web of Science, as well as in the gray literature up to May 2023. Preclinical studies that evaluated alveolar healing after tooth extraction and the intake of sodium alendronate compared with placebo were included. Two investigators were responsible for screening the articles independently, extracting the data, and assessing their quality through the SYRCLE's RoB tool for randomized trials in animal studies. The study selection process, study characteristics, risk of bias in studies, impact of alendronate on bone healing, and certainty of evidence were described in text and table formats. Methodological differences among the studies were restricted to the synthesis methods. The synthesis of qualitative results followed the Synthesis Without Meta-analysis (SWiM) reporting guideline. From the 19 included studies, five were considered to have low risk, three were of unclear risk, and eleven presented a high risk of bias. The studies were considered heterogeneous regarding alendronate posology, including its dosage and route of administration. Furthermore, a variety of animal species, different age ranges, diverse teeth extracted, and exposure or not to ovariectomy contributed to the lack of parity of the selected studies. Our results indicated that alendronate monotherapy negatively affects the early phase of wound healing after tooth extraction in preclinical studies, suggesting that the bone resorption process after tooth extraction in animals treated with alendronate might impair the bone healing process of the extraction socket. In conclusion, alendronate administration restrains bone resorption, thereby delaying alveolar socket healing . Future studies should be conducted to validate these findings and to better understand the effects of alendronate therapy on oral tissues.

Effects of systemic ozone administration on the fresh extraction sockets healing: a histomorphometric and immunohistochemical study in rats.

OBJECTIVE: Studies have highlighted numerous benefits of ozone therapy in the field of medicine and dentistry, including its antimicrobial efficacy against various pathogenic microorganisms, its ability to modulate the immune system effectively, reduce inflammation, prevent hypoxia, and support tissue regeneration. However, its effects on dental extraction healing remain to be elucidated. .Therefore, this study aimed to evaluate the effects of systemically administered ozone (O3) at different doses in the healing of dental extraction sockets in rats. METHODOLOGY: To this end, 72 Wistar rats were randomly divided into four groups after extraction of the right upper central incisor: Group C - control, no systemic treatment; Group OZ0.3 - animals received a single dose of 0.3 mg/kg O3; Group OZ0.7 - a single dose of 0.7 mg/kg O3; and Group OZ1.0 - a single dose of 1.0 mg/kg O3, intraperitoneally. In total, six animals from each group were euthanized at 7, 14, and 21 days after the commencement of treatment. Bone samples were harvested and further analyzed by descriptive histology, histomorphometry, and immunohistochemistry for osteocalcin (OCN) and tartrate-resistant acid phosphatase (TRAP) protein expression. RESULTS: All applied doses of O3 were shown to increase the percentage of bone tissue (PBT) after 21 days compared to group C. After 14 days, the OZ0.7 and OZ1.0 groups showed significantly higher PBT when compared to group C. The OZ1.0 group presented the most beneficial results regarding PBT among groups, which denotes a dose-dependent response. OCN immunostaining was higher in all groups at 21 days. However, after seven and 14 days, the OZ1.0 group showed a significant increase in OCN immunostaining compared to C group. No differences in TRAP+ osteoclasts were found between groups and time points. CONCLUSION: Therefore, O3 therapy at higher doses might be beneficial for bone repair of the alveolar socket following tooth extraction.

One-Stage Approach to Rehabilitate a Hopeless Tooth in the Maxilla by Means of Immediate Dentoalveolar Restoration: Surgical and Prosthetic Considerations.

Contemporary dentistry has increased the demand for predictable functional and esthetic results in a short period of time without compromising the long-term success of rehabilitation. Recent advances in surgical techniques have provided alternatives that allow the prosthetic rehabilitation of complex implant-supported cases through minimally invasive techniques. In this context, immediate dentoalveolar restoration (IDR) was described aiming at restoring function and esthetics through the reconstruction of lost periodontal tissues followed by immediate implant placement in order to minimize treatment time and surgical morbidity in a one-stage approach. Therefore, the aim of this clinical case is to describe the reconstruction and rehabilitation of a hopeless tooth in the maxillary region in a one-stage approach by means of IDR. The proposed steps to rehabilitate the case involved atraumatic dental extraction, immediate implant placement, and hard tissue augmentation by means of cortical-medullary bone graft harvested from the maxillary tuberosity. Afterwards, a provisional restoration was manufactured and installed to the implant allowing immediate prosthesis provisionalization and function in the same operatory time. Six months after the surgical procedure, the final prosthesis was manufactured and installed. The follow-up of nine years demonstrated the preservation of hard and soft tissue without tissue alteration and a successful esthetic outcome. The surgical protocol used allowed the ideal three-dimensional placement of the implant with the restoration of the bone buccal wall, favoring the esthetic and functional outcome of the case with harmony between white and pink esthetics. In conclusion, the employed treatment validated immediate implant-supported restoration of the missing tooth with high predictability. Furthermore, this protocol resulted in fewer surgical interventions, regeneration, and preservation of peri-implant tissues reaching the patient's expectations.

The effects of sodium alendronate on socket healing after tooth extraction: a systematic review of animal studies

Abstract The aim of this systematic review was to answer the following question: "Does alendronate, a nitrogen-containing bisphosphonate, improve or impair alveolar socket healing after tooth extraction in animal models"? To this end, a systematic review of the literature was carried out in PubMed, Scopus, LILACS, Web of Science, as well as in the gray literature up to May 2023. Preclinical studies that evaluated alveolar healing after tooth extraction and the intake of sodium alendronate compared with placebo were included. Two investigators were responsible for screening the articles independently, extracting the data, and assessing their quality through the SYRCLE's RoB tool for randomized trials in animal studies. The study selection process, study characteristics, risk of bias in studies, impact of alendronate on bone healing, and certainty of evidence were described in text and table formats. Methodological differences among the studies were restricted to the synthesis methods. The synthesis of qualitative results followed the Synthesis Without Meta-analysis (SWiM) reporting guideline. From the 19 included studies, five were considered to have low risk, three were of unclear risk, and eleven presented a high risk of bias. The studies were considered heterogeneous regarding alendronate posology, including its dosage and route of administration. Furthermore, a variety of animal species, different age ranges, diverse teeth extracted, and exposure or not to ovariectomy contributed to the lack of parity of the selected studies. Our results indicated that alendronate monotherapy negatively affects the early phase of wound healing after tooth extraction in preclinical studies, suggesting that the bone resorption process after tooth extraction in animals treated with alendronate might impair the bone healing process of the extraction socket. In conclusion, alendronate administration restrains bone resorption, thereby delaying alveolar socket healing . Future studies should be conducted to validate these findings and to better understand the effects of alendronate therapy on oral tissues.

Effects of systemic ozone administration on the fresh extraction sockets healing: a histomorphometric and immunohistochemical study in rats

Abstract Studies have highlighted numerous benefits of ozone therapy in the field of medicine and dentistry, including its antimicrobial efficacy against various pathogenic microorganisms, its ability to modulate the immune system effectively, reduce inflammation, prevent hypoxia, and support tissue regeneration. However, its effects on dental extraction healing remain to be elucidated. Objective Therefore, this study aimed to evaluate the effects of systemically administered ozone (O3) at different doses in the healing of dental extraction sockets in rats. Methodology To this end, 72 Wistar rats were randomly divided into four groups after extraction of the right upper central incisor: Group C - control, no systemic treatment; Group OZ0.3 - animals received a single dose of 0.3 mg/kg O3; Group OZ0.7 - a single dose of 0.7 mg/kg O3; and Group OZ1.0 - a single dose of 1.0 mg/kg O3, intraperitoneally. In total, six animals from each group were euthanized at 7, 14, and 21 days after the commencement of treatment. Bone samples were harvested and further analyzed by descriptive histology, histomorphometry, and immunohistochemistry for osteocalcin (OCN) and tartrate-resistant acid phosphatase (TRAP) protein expression. Results All applied doses of O3 were shown to increase the percentage of bone tissue (PBT) after 21 days compared to group C. After 14 days, the OZ0.7 and OZ1.0 groups showed significantly higher PBT when compared to group C. The OZ1.0 group presented the most beneficial results regarding PBT among groups, which denotes a dose-dependent response. OCN immunostaining was higher in all groups at 21 days. However, after seven and 14 days, the OZ1.0 group showed a significant increase in OCN immunostaining compared to C group. No differences in TRAP+ osteoclasts were found between groups and time points. Conclusion Therefore, O3 therapy at higher doses might be beneficial for bone repair of the alveolar socket following tooth extraction.

Combination of leukocyte and platelet-rich fibrin and demineralized bovine bone graft enhanced bone formation and healing after maxillary sinus augmentation: a randomized clinical trial.

BACKGROUND AND OBJECTIVE: The resorption of alveolar ridge bone and maxillary sinus pneumatization are challenges to implant-supported prosthetic rehabilitation. Bone regeneration using bone substitutes and growth factors are alternatives for maxillary sinus augmentation (MSA). Therefore, we sought to evaluate the effects of the association between leukocyte and platelet-rich fibrin (L-PRF) and deproteinized bovine bone mineral (DBBM) in MSA procedures. MATERIALS AND METHODS: Thirty-six maxillary sinuses from 24 individuals were included in this randomized clinical trial. The maxillary sinuses were randomly grafted with LPRF and DBBM (test group) or grafted only with DBBM (positive control). Dental implants were installed in the test group following two periods of evaluation: after 4 (DBBM+LPRF4) and 8 (DBBM+LPFR8) months of sinus graft healing, while the control group received implants only after 8 months. Cone beam computed tomography (CBCT) was taken 1 week after surgery (T1) and before implant placement (T2). Bone samples were collected during implant placement for histomorphometric and immunohistochemical (IHC) analysis. The primary implant stability was assessed by resonance frequency analysis. RESULTS: CBCT analysis demonstrated a significant decrease in bone volume from T1 to T2 in all groups without differences among them. Histologically, the test group showed significantly increase in bone neoformation in both periods of evaluation (LPRF+DBBM4: 44.70±14.01%; LPRF+DBBM8: 46.56±12.25%) compared to the control group (32.34±9.49%). The control group showed the highest percentage of residual graft. IHC analysis showed increased staining intensity of osteocalcin (OCN), vascular endothelial growth factor (VEGF), and runt related transcription factor 2 (RUNX-2) in LPRF+DBBM4 group, and osteopontin (OPN) in the L-PRF+DBBM8. Primary implant stability was successfully achieved (above 60 in implant stability quotient) in all the evaluated groups. CONCLUSION: Combination of L-PRF and DBBM increased and accelerated new bone formation allowing early implant placement probably due to the higher protein expression of RUNX2, VEGF, OCN, and OPN. These data suggest that the use of L-PRF might be an interesting alternative to use in combination with DBBM for augment the maxillary sinuses allowing the installation of appropriate length implants in shorter period of time. CLINICAL RELEVANCE: This study showed improvement in bone neoformation and accelerated healing when associating L-PRF and DBBM for maxillary sinus augmentation procedures. TRIAL REGISTRATION: This study was registered before participant recruitment in Brazilian Registry of Clinical Trials (ReBEC - RBR-95m73t).

The Relationship between Hypertension and Periodontitis: A Cross-Sectional Study.

Recent evidence suggests an association between hypertension and periodontitis, although the pathways and implications underlying both chronic conditions are still poorly understood. Therefore, the aim of this study was to evaluate the relationship between hypertension and periodontitis through an observational clinical study using periodontal, physical, and biochemical analyses in hypertensive and non-hypertensive individuals with periodontitis. A total of one hundred patients were divided into two groups. The first group was hypertensive patients with periodontitis. The second group was non-hypertensive patients with periodontitis. Periodontal parameters of probing depth, bleeding on probing, and clinical attachment level were evaluated. The systolic, diastolic, mean, and differential blood pressure were measured in the physical examination. In addition, body mass index and waist-hip ratio were verified. Biochemical tests for glycated hemoglobin, fasting blood glucose, estimated blood glucose, total cholesterol, high-density lipoprotein, creatinine, glutamate pyruvate transaminase, glutamic oxaloacetic transaminase, and C-reactive protein were evaluated. The data were submitted for statistical analysis (α = 0.05%). The results of this study demonstrated that patients with cardiovascular disease did not present with worse periodontal clinical parameters in the conditions studied. However, it is important to bear in mind that this cross-sectional study has some inherent limitations to its design; therefore, to study the relationship between hypertension and periodontitis further, an interventional randomized clinical trial should be conducted.

The Effect of Non-Surgical Periodontal Treatment on Patients with Combined Refractory Arterial Hypertension and Stage III, Grade B Periodontitis: A Preliminary Prospective Clinical Study.

We sought to evaluate the effects of non-surgical periodontal treatment (NSPT) on periodontal clinical parameters, systemic blood pressure (BP), and plasma levels of systemic inflammation markers in patients with combined refractory arterial hypertension (RAH) and stage III grade B periodontitis. Twenty-seven participants with RAH and periodontitis received NSPT. The analyzed clinical parameters were probing depth (PD), clinical attachment level (CAL), bleeding on probing (BOP), and plaque index (PI). An assessment was performed for systemic BP, complete blood count, coagulogram, creatinine measurement, C-reactive protein (CRP), glycated hemoglobin, cholesterol, glutamic oxaloacetic transaminase, glutamate pyruvic transaminase, waist-hip ratio, and body mass index. In the follow-up period, twenty-two patients were evaluated at baseline and after 90 and 180 days. The data were submitted for statistical analysis (α = 0.05%). As expected, the clinical results showed a significant improvement in the percentages of PI, BOP, PD, and CAL, which were statistically significant at 90 and 180 days (p < 0.0001). Importantly, NSPT significantly reduced the blood level of CRP (p < 0.02). However, no significant reduction in BP parameters was noted in the evaluated follow-up periods. NSPT, despite the benefits in periodontal clinical parameters, reduced the plasma level of CRP but not the BP in patients with combined RAH and periodontitis.

Pharmacological Therapies for the Management of Inflammatory Bone Resorption in Periodontal Disease: A Review of Preclinical Studies.

Periodontitis, a highly prevalent multicausal chronic inflammatory and destructive disease, develops as a result of complex host-parasite interactions. Dysbiotic bacterial biofilm in contact with the gingival tissues initiates a cascade of inflammatory events, mediated and modulated by the host's immune response, which is characterized by increased expression of several inflammatory mediators such as cytokines and chemokines in the connective tissue. If periodontal disease (PD) is left untreated, it results in the destruction of the supporting tissues around the teeth, including periodontal ligament, cementum, and alveolar bone, which lead to a wide range of disabilities and poor quality of life, thus imposing significant burdens. This process depends on the differentiation and activity of osteoclasts, the cells responsible for reabsorbing the bone tissue. Therefore, the inhibition of differentiation or activity of these cells is a promising strategy for controlling bone resorption. Several pharmacological drugs that target osteoclasts and inflammatory cells with immunomodulatory and anti-inflammatory effects, such as bisphosphonates, anti-RANK-L antibody, strontium ranelate, cathepsin inhibitors, curcumin, flavonoids, specialized proresolving mediators, and probiotics, were already described to manage inflammatory bone resorption during experimental PD progression in preclinical studies. Meantime, a growing number of studies have described the beneficial effects of herbal products in inhibiting bone resorption in experimental PD. Therefore, this review summarizes the role of several pharmacological drugs used for PD prevention and treatment and highlights the targeted action of all those drugs with antiresorptive properties. In addition, our review provides a timely and critical appraisal for the scientific rationale use of the antiresorptive and immunomodulatory medications in preclinical studies, which will help to understand the basis for its clinical application.

Voluntary physical activity mitigates alveolar bone loss in mice with ligature-induced experimental periodontitis.

OBJECTIVE: To investigate the effect of voluntary physical activity (VPA) on inflammatory profile and the progression of experimental periodontal disease (PD) in mice. METHODS: Male C57BL/6 mice were randomly distributed into Control; VPA; PD and PD/VPA groups. We registered VPA (total volume of revolutions) and average speed (revolutions/minute) in a free running wheel for 30 days. On the 15th day, animals from the PD and PD/VPA groups received ligatures on the upper second molars bilaterally. On the 30th day animals were euthanized, and PD progression was assessed by measuring alveolar bone loss (ABL - the linear distance between the cemento-enamel junction and the alveolar bone crest on the teeth buccal surface). Gene expression of RANKL (kappa nuclear factor B receptor) OPG (osteoprotegerin), IL-1ß (interleukin 1 beta), IL-6 (interleukin 6) and TNF-α (tumor necrosis factor alpha) were evaluated by real-time PCR (quantitative Polymerase Chain Reaction - relative gene expression). RESULTS: The total volume of physical activity and the activity speed decreased along the seven days after ligature-placement (p < 0.05), returning to a similar pattern in relation to VPA group. Ligature placement produced significant bone resorption, and increased RANKL, IL-1ß, IL-6 and TNF-α expression. VPA reduced ABL (p < 0,05) and the expression of TNF-α and IL-1ß, whereas increased OPG expression. CONCLUSION: Animals induced to PD with access to the VPA wheel presented both lower gingival inflammation and less alveolar bone resorption in comparison to animals without access to the wheel.

Obesity influences the proteome of periodontal ligament tissues following periodontitis induction in rats.

BACKGROUND AND OBJECTIVES: Many studies have been conducted to better understand the molecular mechanism involved with periodontitis progression. There has been growing interest in the potential impact of obesity on periodontitis onset and progression, but the mechanisms involved remain to be elucidated. The present study was designed to determine the impact of obesity on experimentally induced periodontitis in rats and identify novel pathways involved. METHODS: Sixteen Holtzman rats were distributed into two groups (n = 8): ligature-induced periodontitis (P) and obesity plus ligature-induced periodontitis (OP). Obesity was induced by a high-fat diet for 70 days, whereas periodontitis was induced for 20 days, with a cotton thread placed around the upper first molars bilaterally. Alveolar bone loss was measured by microtomographic analysis and histologically by histometry on the hemimaxillae. The protein composition of the periodontal ligament was evaluated by proteomic analysis. RESULTS: Data analysis (body weight, adipose tissue weight, and blood test) confirmed obesity induction, whereas bone loss was confirmed by micro-CT and histologic analyses. Proteome analysis from the periodontal ligament tissues (PDL) identified 819 proteins, 53 exclusive to the P group, 28 exclusive to the OP group, and 738 commonly expressed. Validation was performed by immunohistochemistry for selected proteins (spondin1, vinculin, and TRAP). CONCLUSION: Histologically, it was found that obesity did not significantly affect bone loss resulting from periodontitis. However, the present study's findings indicated that obesity affects the proteome of PDL submitted to experimental periodontitis, allowing for identifying potential targets for personalized approaches.

Periodontal regeneration: is it still a goal in clinical periodontology?

In the last decades, Periodontal Regeneration has been one of the most discussed topics in Periodontics, attracting the attention of researchers and clinicians. This can be justified by the evident and continuous progress observed in the field, characterized by a better understanding of the biological mechanisms involved, significant improvement of operative and technical principles, and the emergence of a wide range of biomaterials available for this purpose. Together, these aspects put the theme much in evidence in the search for functional and esthetic therapeutic solutions for periodontal tissue destruction. Despite the evident evolution, periodontal regeneration may be challenging and require the clinician to carefully evaluate each case before making a therapeutic decision. With a critical reassessment of the clinical and preclinical literature, the present study aimed to discuss the topic to answer whether Periodontal Regeneration is still a goal in clinical periodontology. The main aspects involved in the probability of success or failure of regenerative approaches were considered. A greater focus was given to intrabony and furcation defects, clinical conditions with greater therapeutic predictability. Aspects such as more appropriate materials/approaches, long-term benefits and their justification for a higher initial cost were discussed for each condition. In general, deep intrabony defects associated with residual pockets and buccal/lingual class II furcation lesions have predictable and clinically relevant results. Careful selection of the case (based on patient and defect characteristics) and excellent maintenance are essential conditions to ensure initial and long-term success.

A Prosthetic and Surgical Approach for Full-Arch Rehabilitation in Atrophic Maxilla Previously Affected by Peri-Implantitis.

Rehabilitation of atrophic maxilla with dental implants is still a challenge in clinical practice especially in cases of alveolar bone resorption due to peri-implantitis and pneumatization of the maxillary sinuses. Several surgical approaches have been employed to reconstruct the lost tissues allowing the proper tridimensional position of the implants. In this context, the aim of this case report is to describe a surgical and prosthetic approach to fully rehabilitate the atrophic maxilla with dental implants. The patient presented with unsatisfactory functional and esthetical implant-supported prosthesis with some of the implants already lost by peri-implantitis. The remaining three implants were also affected by peri-implantitis. Reversal prosthetic planning was performed, and a provisional prosthesis was fabricated and anchored in two short implants. Sinus floor augmentation procedure and onlay bone graft were then accomplished. After a healing period of 8 months, digital-guided surgery approach was performed to place the implants. Finally, a definitive prosthesis was installed. One-year follow-up has revealed stabilization of the bone tissue level, successful osseointegration, and a pleasant esthetic and functional result. A proper diagnosis and careful planning play an important role to enhance precision and to achieve patient esthetic and functional outcomes.

Effects of obesity on periodontal tissue remodeling during orthodontic movement.

INTRODUCTION: Orthodontic movement triggers a sequence of cellular and molecular events that may be affected by different systemic conditions. This study evaluated the effect of obesity on rat periodontal tissue remodeling induced by mechanical orthodontic force. METHODS: Thirty-two Holtzman rats were distributed into 4 groups: control, obesity induction (O), orthodontic movement (M), and obesity induction and orthodontic movement (OM). Obesity was induced by a high-fat diet for 90 days. After 15 days of orthodontic movement, the animals were killed. Obesity induction was confirmed by animal body weight, adipose tissue weight, and serologic analysis. Periodontal tissue remodeling was evaluated using microcomputed tomography and histologic analysis. The gene expression of adipokines and cytokines in gingival tissues was evaluated. RESULTS: An increase in body and adipose tissue weight was observed in the obesity induction groups. The O group presented an increase in lipids and blood glucose. The OM group showed a decrease in bone volume fraction and bone mineral density compared with all other groups and a tendency for more rapid tooth movement than the M group. The OM group showed a higher quantity of inflammatory cells and higher Mmp1 expression than the O group. The O and OM groups showed higher Nampt expression than the control group and lower Nampt expression than the M group. CONCLUSIONS: Obesity modulates periodontal tissue remodeling during orthodontic movement and results in more inflammation and bone loss than in nonobese animals.

Chalcone T4, a novel chalconic compound, inhibits inflammatory bone resorption in vivo and suppresses osteoclastogenesis in vitro.

OBJECTIVE: This study aimed to assess the effect of a novel synthetic chalcone, Chalcone T4, on a murine model of periodontitis and on RANKL-induced osteoclastogenesis in vitro. BACKGROUND: Chalcones are natural compounds with anti-inflammatory properties, and its synthetic analogs with enhanced biological effects have potential as therapeutic agents. Periodontitis is characterized by chronic inflammation of the periodontium and alveolar bone resorption. Safe and effective anti-inflammatory agents can have an important additive effect in the treatment in this disease. METHODS: Periodontitis was induced via the installation of a ligature around the first molar. Rats (n = 32) received Chalcone T4 (5 and 50 mg/kg) or distilled water by gavage daily for 15 days. Outcomes assessed were bone resorption (µCT), TNF-α production (ELISA), cellular infiltrate, and collagen content (stereometric analysis, CD45+ cells by immunohistochemistry), and activation of NFATc1 and NF-kB (immunohistochemistry). In vitro, RAW 264.7 were treated with Chalcone T4 and stimulated with RANKL for assessment of osteoclast differentiation (actin ring staining) and activity (pit assay). RESULTS: Chalcone T4 significantly reduced periodontitis-associated bone resorption, as well as the cellular infiltrate, while increasing the collagen content. Production of TNF-α, infiltration of CD45-positive cells, and NF-kB activation were markedly reduced. In vitro, chalcone T4 inhibited both osteoclast differentiation and activity. CONCLUSION: Chalcone T4 significantly inhibited alveolar bone resorption and inflammation in vivo and RANKL-induced osteoclastogenesis in vitro, suggesting a therapeutic role for this compound in the treatment of periodontitis.

Periodontal regeneration: is it still a goal in clinical periodontology?

Abstract In the last decades, Periodontal Regeneration has been one of the most discussed topics in Periodontics, attracting the attention of researchers and clinicians. This can be justified by the evident and continuous progress observed in the field, characterized by a better understanding of the biological mechanisms involved, significant improvement of operative and technical principles, and the emergence of a wide range of biomaterials available for this purpose. Together, these aspects put the theme much in evidence in the search for functional and esthetic therapeutic solutions for periodontal tissue destruction. Despite the evident evolution, periodontal regeneration may be challenging and require the clinician to carefully evaluate each case before making a therapeutic decision. With a critical reassessment of the clinical and preclinical literature, the present study aimed to discuss the topic to answer whether Periodontal Regeneration is still a goal in clinical periodontology. The main aspects involved in the probability of success or failure of regenerative approaches were considered. A greater focus was given to intrabony and furcation defects, clinical conditions with greater therapeutic predictability. Aspects such as more appropriate materials/approaches, long-term benefits and their justification for a higher initial cost were discussed for each condition. In general, deep intrabony defects associated with residual pockets and buccal/lingual class II furcation lesions have predictable and clinically relevant results. Careful selection of the case (based on patient and defect characteristics) and excellent maintenance are essential conditions to ensure initial and long-term success.

Alendronate Impairs Healing of Calvaria Critical Defects After Bone Graft With Different Bone Substitute Materials.

PURPOSE: The aim of this preclinical study was to evaluate the healing of critical-sized defects (CSDs) in the calvarial bone of rats grafted with deproteinized bovine bone graft (DBB) and with a combination of hydroxyapatite (HA) and ß-tricalcium phosphate (TCP) and bisphosphonate treatment. MATERIALS AND METHODS: Eighty-four animals were randomly divided into 2 groups according to the type of solution administered: the control group (CTR, saline solution) and the test group (alendronate [ALD]; sodium alendronate-50 µg/kg/day). Medications were administered via oral gavage starting 15 days before the surgical procedure until the end of the experiment. A CSD (5 mm in diameter) was made in the calvaria of each animal, and the rats were randomly allocated to 3 subgroups according to the biomaterial used to fill the defect: coagulum, DBB, and HA/TCP. The animals were sacrificed 15 and 60 days after the surgical procedure (n = 7 animals/period/subgroup). Microcomputed tomography was used to evaluate the percentage of mineralized tissues (volume). The amount of newly formed bone and remaining bone substitute material in the calvaria were analyzed by histomorphometry. RESULTS: There were no differences between the CTR and ALD groups with regard to the volume of mineralized tissues. The DBB and HA/TCP subgroups of CTR animals presented a significant increase in newly formed bone compared with these subgroups of ALD animals after 60 days of healing. CONCLUSIONS: Collectively, our findings indicate that the use of oral ALD reduced bone formation in CSD in the calvaria of rats grafted with DBB and HA/TCP.

Effects of orthodontic tooth extrusion produced by different techniques, on the periodontal tissues: a histological study in dogs.

OBJECTIVE: The aim of this study was to compare the periodontal tissue changes resulting from different methods of orthodontic tooth extrusion in dogs. MATERIALS AND METHODS: Notches were surgically prepared in the root surface at the bone crest level of the first premolars of mongrel dogs. After 37 days, extrusion of the first lower and upper premolars was randomly performed by 3 different methods: conventional orthodontic extrusion (OE); open flap debridement performed immediately before orthodontic extrusion (OF); and orthodontic extrusion associated with weekly fiberotomy and scaling (FS). For all groups, extrusion was performed for 21 days followed by one-month retention and sacrifice. Periodontal parameters, descriptive histology, and histomorphometric analyses were performed at the end of the experimental period. RESULTS: The median extrusion was 2.25 in the fiberotomy group, 2.0 mm in the open flap group and 1.0 mm in the orthodontic extrusion group with no significant differences between groups. The highest distance between reference notch and bone crest was observed in the fiberotomy group (p < 0.05). Histologically, radicular resorption repaired with cellular cementum was detected in all groups. CONCLUSIONS: Tooth extrusion was successfully achieved with all of the different methods of orthodontic tooth extrusion with no statistical significance between techniques. The fiberotomy approach was effective in avoiding coronal displacement of periodontal tissues. Fiberotomy associated with scaling should be indicated if the objective of the treatment is extrusion without periodontal tissue displacement.

Long-term evaluation of alendronate treatment on the healing of calvaria bone defects in rats. Biochemical, histological and immunohistochemical analyses.

OBJECTIVE: The aim of this study was to investigate the effects of the long-term alendronate administration on bone healing in defects created in rat calvarias. MATERIALS AND METHODS: Female Wistar rats were randomly distributed into 2 groups: Control (CTL): animals received saline solution once a week; and Alendronate (ALD): rats underwent alendronate treatment (1 mg/kg/weekly). After 120 days from the commencement of treatment, a critical size defect was created in all animals, and 10 animals from each group were sacrificed at 5, 10, 15, 20, 25, 30, 45 and 60-days after the defect creation. On the day of sacrifice, urine and blood samples were collected for determination of the serum levels of bone resorption and formation markers by enzyme linked immunosorbent assay, and the urinary concentration of deoxypyridinoline. Bone mineral density (BMD) in the femurs, descriptive histology, tartrate-resistant acid-phosphatase staining and immunohistochemical analyzes were assessed in the calvaria. RESULTS: Alendronate group showed increased BMD compared to the test group. The concentration of C-terminal telopeptide of type I collagen and deoxypyridinoline decreased significantly, and the concentration of aminoterminal propeptide of procollagen type 1 and osteocalcin were significant lower in the alendronate group. Immunohistochemical analysis showed significant downregulation in the inducible nitric oxide synthase, runt-related transcription factor-2, cathepsin-K and receptor activator of nuclear factor kappa-B ligand expression in the alendronate group. Vascular endothelial growth factor and osteopontin were upregulated in the later periods of alendronate group. CONCLUSIONS: Our results suggest that long-term treatment with alendronate did not compromise the repair processing of critical size defects in rat.

Topical application of lectin Artin M improves wound healing in defects created in the palatal mucosa: an in vivo study in dogs.

Previous studies have shown that topical application of lectin Artin-M accelerates wound healing in the rat oral mucosa. The aim of this study was to evaluate, by means of histology and immunohistochemistry (IHC) the effects of Artin-M on wound healing in the palatal mucosa in dogs. Three full thickness wounds of 6 mm diameter were surgically created in the palatal mucosa of twenty dogs and randomly divided into three groups according to one of the treatment assigned: Group C-Control (coagulum); Group A-Artin-M gel; Group V-Vehicle (carboxymethylcellulose 3%). Each animal received all the three experimental treatments. Afterwards, four animals were killed at 2, 4, 7, 14 and 21 days post-surgery. Wounded areas were photographed and scored for macroscopic evaluation. Biopsies were harvested and used for descriptive histological analysis, proliferating cell nuclear antigen IHC and measurement of myeloperoxidase activity. The results demonstrated faster wound closure in group A in comparison to the other groups in all the periods evaluated. Histological analyses exhibited improved re-epithelialization and collagen fiber formation resulting in faster maturation of granulation tissue in group A compared to the other groups by day 14. Treatment with Artin-M gel significantly induced cell proliferation and increased volumetric density of fibroblasts at day 2 and 4 (p < 0.05). Neutrophil infiltration in group A was significantly higher than the other groups (p < 0.05) at the same time points. Collectively, our findings demonstrated that Artin-M may potentially favor wound healing on palatal mucosa lesions via recruitment of neutrophils and promotion of cell proliferation.