Clinical and radiologic treatment outcomes of implant presence tirggered-MRONJ: Systematic review of literature.

BACKGROUND: The present systematic review evaluated clinical and radiographic features and treatment outcomes of peri-implantitis-induced medication-related osteonecrosis of the jaws (Pi-MRONJ). MATERIALS AND METHODS: Literature search was performed in PubMed/MEDLINE, Cochrane CENTRAL, Web of Science, and Scopus databases. Studies reporting Pi-MRONJ were included. No time restrictions were applied. RESULTS: In total, 571 articles were retrieved, and 24 articles were included in the final review. Study population consisted of 111 patients (70% pharmacologically treated for osteoporosis and 30% for oncologic disease). Pi-MRONJ was characterized by pain, bone exposure and suppuration, and involved a single implant in 55 cases, two implants in 37 cases, three implants in 10 cases, and more than four implants in nine cases. Most of the lesions were assigned Stage II and III. MRONJ developed on average 46.5 ± 33.2 months following implant placement. Sixty-one lesions were surgically treated with implant removal and debridement of the surrounding necrotic bone. Complete wound healing was observed in 85% of cases. CONCLUSIONS: The presence of dental implants in patients treated with antiresorptive drugs should be considered as a potential risk factor for MRONJ onset. In cases of periimplantitis with delayed wound healing following nonsurgical therapy, the clinician should rule out the presence of Pi-MRONJ.

Osteoblasts and Fibroblasts Interaction with a Porcine Acellular Dermal Matrix Membrane.

The use of collagen membranes has remained the gold standard in GTR/GBR. In this study, the features and the biological activities of an acellular porcine dermis collagen matrix membrane applicable during dental surgery were investigated, and also by applying hydration with NaCl. Thus, two tested membranes were distinguished, the H-Membrane and Membrane, compared to the control cell culture plastic. The characterization was performed by SEM and histological analyses. In contrast, the biocompatibility was investigated on HGF and HOB cells at 3, 7, and 14 days by MTT for proliferation study; by SEM and histology for cell interaction study; and by RT-PCR for function-related genes study. In HOBs seeded on membranes, mineralization functions by ALP assay and Alizarin Red staining were also investigated. Results indicated that the tested membranes, especially when hydrated, can promote the proliferation and attachment of cells at each time. Furthermore, membranes significantly increased ALP and mineralization activities in HOBs as well as the osteoblastic-related genes ALP and OCN. Similarly, membranes significantly increased ECM-related and MMP8 gene expression in HGFs. In conclusion, the tested acellular porcine dermis collagen matrix membrane, mainly when it is hydrated, behaved as a suitable microenvironment for oral cells.

Non-impacted tooth extractions and antibiotic treatment: A RCT study.

OBJECTIVES: A controlled, single-blind, randomized clinical trial was performed to evaluate usefulness of antibiotics in preventing pain and complications after tooth extractions and benefits of probiotics in reducing gastro-intestinal symptoms associated with antibiotic therapy. MATERIALS AND METHODS: A total of 159 patients were enrolled in this trial. After tooth extractions, patients were allocated to one of the groups: group 1 received postoperatively amoxicillin + clavulanic acid; group 2 received the same antibiotic therapy with an adjunctive probiotic treatment; and group 3 received neither antibiotics nor probiotics. Follow-up visits were planned at 7, 14, and 21 days after tooth extractions (T1, T2, and T3), and parameters assessed were pain, presence of abscess, edema, fever, alveolitis, trismus, pain, difficulty in daily routine activities, and gastro-intestinal symptoms. RESULTS: The number of patients reporting pain at T1 was significantly higher in the control group when compared to group 2 (p = .016), while no difference for pain intensity was observed between groups. No surgical site infection was observed in any of the groups. Intestinal symptoms seemed to be tackled by probiotic administration. CONCLUSIONS: Pain was the most important symptom in the control group. Antibiotics were not necessary after non-impacted tooth extractions, and probiotics can reduce gastro-intestinal symptoms associated with antibiotics.

A perspective on dental activity during COVID-19: The Italian survey.

OBJECTIVES: During the months of March and April 2020, Italy saw an exponential outbreak of COVID-19 epidemic. Dental practitioners were particularly limited in their routine activity, and the sole performance of urgent treatments was strongly encouraged during the peak of the epidemic. A survey among dental professionals was performed between 6th and 13th of April, in order to evaluate the status of dental practice during COVID-19 in Italy. MATERIALS AND METHODS: An online anonymous questionnaire was administered to retrieve data on the dental procedures performed, the preventive measures adopted, and the predictions on the future changes in dentistry following the pandemic. RESULTS: The survey was completed by 3,254 respondents and, according to the results obtained, dental activity was reduced by the 95% and limited to urgent treatments. The majority of the surveyed dentists employed additional personal protective equipment compared to normal routine, although in a non-negligible number of cases difficulty in retrieving the necessary equipment was reported. CONCLUSIONS: The survey provided a snapshot of dental activity during the SARS-CoV-2 outbreak. Overall, following the peak of the epidemic, it is probable that dental activities will undergo some relevant changes prior to fully restart.

Antibiotic's effectiveness after erupted tooth extractions: A retrospective study.

OBJECTIVE: The purpose of this retrospective study was to assess the influence of antibiotics on the development of alveolitis after tooth extractions. MATERIALS AND METHODS: The study population consisted of patients who had erupted tooth extractions in 3 centers. The patients' medical records were collected for several parameters. Moreover, use of antibiotics was evaluated. The primary outcome was the development of alveolitis during the postoperative period. The secondary outcome measure was the possible associations between alveolitis and other patients' characteristics. RESULTS: A total of 1579 patient charts were screened. The patients enrolled in the study were 418 (159 males and 259 females). Alveolitis was reported for 12 extraction sites (2.87%). Six were in the group of patients that received antibiotics (2.14% out of 280 patients treated with antibiotics), and six were in the group of patients that did not receive antibiotics (4.35% out of 138 patients not receiving antibiotics). None of patient-level parameters showed any significant association with the development of alveolitis. CONCLUSION: In conclusion, this study showed that the use of antibiotics after erupted tooth extractions is not useful in preventing alveolitis. Larger, prospective, and randomized studies are needed before incorporating these findings into the daily clinical practice.

Clinical Success of Dental Implants Placed in Posterior Mandible Augmented With Interpositional Block Graft: 3-Year Results From a Prospective Cohort Clinical Study.

PURPOSE: The purpose of the present cohort study was to investigate the 3-year efficacy and clinical performance of implant-supported rehabilitations in posterior mandibles augmented with the sandwich osteotomy technique. MATERIALS AND METHODS: Twenty-three partially edentulous patients who developed atrophy of the posterior mandible (residual ridge height, 3 to 7 mm) were treated (32 surgical sites) with vertical bone augmentation using interpositional equine cancellous bone blocks and porcine corticocancellous bone particulate. All implants were placed 4 months after augmentation and were loaded with fixed dental prostheses. One side per patient was selected and followed for 3 years, and the patient was the unit of analysis. Linear radiographic vertical bone gain and peri-implant marginal bone loss were assessed; secondary outcomes-complication rates after surgery, prosthesis and implant failure rates, width of keratinized mucosa, and patient satisfaction-were evaluated. RESULTS: All patients reported postoperative paresthesia that resolved over a period of 2 months after the augmentation procedure. The mean vertical bone gain was 5.6 mm after 4 months. Ninety-one dental implants were positioned into the augmented areas. The global 3-year survival rate was 95.5%. The mean peri-implant marginal bone loss around implants was 1.06 ± 0.37 mm 3 years after loading, whereas the width of keratinized mucosa had an overall increase of 0.39 ± 0.36 mm. CONCLUSION: The results of the present 3-year study suggested high success rates for implants placed in areas augmented with the osteotomy sandwich technique. This surgical approach could be helpful in the presence of a low residual vertical height in the posterior mandible before implant placement.

Medication-Related Osteonecrosis of the Jaw: The Use of Leukocyte-Platelet-Rich Fibrin as an Adjunct in the Treatment.

Medication-related osteonecrosis of the jaw are bone exposures in the maxillofacial region that does not heal after 8 weeks from the observation of a health care provider in patients with history of the intake of antiresorptive agents and no previous irradiation of the craniofacial region. Initially attributed only to the intake of bisphosphonates they have later been associated also with the intake of other classes of antiresorptive medications.This retrospective study analyzed records from patients with documented medication-related osteonecrosis of the jaws treated in our unit. Clinical data, comorbidities and concurrent medications, treatment outcome information such us number of repeated treatments needed, antibiotic used, type of treatment adopted were recorded. Baseline demographics for the included records of 15 patients (mean age: 64 years) revealed a treatment success rate of 73.3% (mean observation period: 42.2 months), failure rate of 26.6%, dental extraction trigger rate of 33.3%, and a spontaneous trigger rate of 40%.Zolendronate and denosumav were the medications most frequently associated with the upset of medication-related osteonecrosis of the jaw (60% of the sample). In 8 cases out of the 11 that were successful, the surgical treatment had to be repeated more than once. Leukocyte-platelet-rich fibrin led to the resolution of 11 of the 14 cases in which it was used.

Nonsurgical Treatment of Peri-implantitis Without Eliminating Granulation Tissue: A 3-Year Study.

OBJECTIVES: The purpose of this study was to evaluate a nonsurgical approach toward peri-implantitis by means of mechanical debridement and local detoxification leaving granulation tissue into the peri-implant pockets. MATERIALS AND METHODS: An analysis was performed on the outcomes of 2 nonsurgical protocols: mechanical debridement plus chemical detoxification with 0.2% chlorhexidine and chlortetracycline hydrochloride (test), and mechanical debridement alone (control). Measures were collected at baseline, 3, 24, and 36 months after treatment. RESULTS: Seventy-five implants with peri-implantitis were included. At a 36-month evaluation, mean pocket probing depth was 3.15 ± 0.32 mm for the test group and 5.97 ± 0.90 mm for the control group, the difference being significant. An improvement of marginal bone level was recorded for the test group, whether the control group showed a further marginal bone loss. Treatment success was 100% in the test group and 31.4% in the control group. CONCLUSION: Nonsurgical implant debridement alone seemed not efficient in the treatment of peri-implantitis. Further longitudinal studies are required to evaluate the efficacy of mechanical debridement with chemical detoxification and removal of granulation tissues against mechanical debridement with chemical detoxification alone.

Regenerative properties of collagenated porcine bone grafts in human maxilla: demonstrative study of the kinetics by synchrotron radiation microtomography and light microscopy.

OBJECTIVES: Recently, it has been reported that heterologous biomaterials, where the collagen matrix is preserved, seem to facilitate blood clotting and the subsequent invasion of repairing and regenerative cells. This study aimed at evaluating the healing of human extraction sockets grafted with a collagenated cortico-cancellous porcine bone (mp3®, OsteoBiol®, Tecnoss®, Giaveno, Italy) by synchrotron radiation X-ray microtomography (microCT) and histology in order to have a 3D quantitative characterization over time. MATERIALS AND METHODS: Ridge preservation with porcine bone and collagen membrane was performed on 21 patients using a flapless approach and a secondary soft tissue closure. At the time of implant placement, six bone samples were harvested, two in the 3-month group, two in the 6-month group, one in the 12-month group post-surgery, and one spontaneously healed control, and evaluated by microCT and histology. RESULTS: MicroCT revealed that in the grafted sites there were a greater number of trabeculae, although they appeared thinner than in the control sites; these trabeculae homogenously filled the defects, suggesting an improved strength of the socket. Histology showed that over time, the amount of biomaterial decreased and the newly formed bone increased, while less dense bone with wider marrow spaces was detected in the control sample, supporting synchrotron findings. CONCLUSIONS: The morphometric data converge to indicate the suitability of porcine bone for the preservation of post-extraction sockets. CLINICAL RELEVANCE: The use of mp3 is encouraged to preserve and heal sockets.

Clinical and Histological changes after ridge preservation with two xenografts: preliminary results from a multicentre randomized controlled clinical trial.

OBJECTIVES: To evaluate and compare clinical and histological changes after ridge preservation procedures with those of spontaneous healing. MATERIALS AND METHODS: Ninety patients were enrolled in the present randomized controlled clinical trial and underwent single-tooth extraction in the premolar/molar areas. Thirty sites were grafted with collagenated cortico-cancellous (coll), 30 sites with cortical (cort) porcine bone and 30 sites underwent natural healing. Primary (vertical and horizontal bone changes after 3 months) and secondary outcomes (histomorphometric after 3 months) were evaluated at implant placement. RESULTS: The vertical bone changes at the grafted sockets were significantly (p < 0.0001) lower (0.30 mm for cort group and 0.57 mm for coll group) when compared to non-grafted sockets (2.10 mm for nat group). Moreover, the width reduction of the coll (0.93 mm) and cort (1.33 mm) groups was significantly lower (p < 0.0001) than the non-grafted group (3.60 mm). The analysis of subgroups attested that when premolar and molar sites were compared, the buccal bone loss appeared to be dependent both on tooth position and grafting material employed. CONCLUSION: The ridge preservation procedures had significantly better outcomes when compared to natural healing. The biomaterials did not differ for maintenance of bone width; even though, the bone height seemed to be better preserved with the cortical porcine bone.

Odontogenic Orofacial Infections.

Acute dental abscess is a frequent and sometimes underestimated disease of the oral cavity. The acute dental abscess usually occurs secondary to caries, trauma, or failed endodontic treatment. After the intact pulp chamber is opened, colonization of the root canals takes place with a variable set of anaerobic bacteria, which colonize the walls of the necrotic root canals forming a specialized mixed anaerobic biofilm. Asymptomatic necrosis is common. However, abscess formation occurs when these bacteria and their toxic products breach into the periapical tissues through the apical foramen and induce acute inflammation and pus formation. The main signs and symptoms of the acute dental abscess (often referred to as a periapical abscess or infection) are pain, swelling, erythema, and suppuration usually localized to the affected tooth, even if the abscess can eventually spread causing a severe odontogenic infection which is characterized by local and systemic involvement culminating in sepsis syndrome. The vast majority of dental abscesses respond to antibiotic treatment, however, in some patients surgical management of the infection may be indicated. In the present work, a retrospective analysis of the patients with dental orofacial infections referred to the Unit of Dentistry and Maxillofacial Surgery of the University of Verona from 1991 to 2011 has been performed.

Bacterial adhesion on direct and indirect dental restorative composite resins: An in vitro study on a natural biofilm.

STATEMENT OF PROBLEM: Both direct and indirect techniques are used for dental restorations. Which technique should be preferred or whether they are equivalent with respect to bacterial adhesion is unclear. PURPOSE: The purpose of this in vitro study was to determine the affinity of bacterial biofilm to dental restorative composite resins placed directly and indirectly. MATERIAL AND METHODS: Five direct composite resins for restorations (Venus Diamond, Adonis, Optifil, Enamel Plus HRi, Clearfil Majesty Esthetic) and 3 indirect composite resins (Gradia, Estenia, Signum) were selected. The materials were incubated in unstimulated whole saliva for 1 day. The biofilms grown were collected and their bacterial cells counted. In parallel, the composite resin surface morphology was analyzed with atomic force microscopy. Both bacterial cell count and surface topography parameters were subjected to statistical analysis (α=.05). RESULTS: Indirect composite resins showed significantly lower levels than direct composite resins for bacterial cell adhesion, (P<.001). No significant differences were observed within the direct composite resins (P>.05). However, within the indirect composite resins a significantly lower level was found for Gradia than Estenia or Signum (P<.01). A partial correlation was observed between composite resin roughness and bacterial adhesion when the second and particularly the third-order statistical moments of the composite resin height distributions were considered. CONCLUSIONS: Indirect dental restorative composite resins were found to be less prone to biofilm adhesion than direct composite resins. A correlation of bacterial adhesion to surface morphology exists that is described by kurtosis; thus, advanced data analysis is required to discover possible insights into the biologic effects of morphology.

Submerged flapless technique vs. conventional flap approach for implant placement: experimental domestic pig study with 12-month follow-up.

OBJECTIVES: The aim of our study was to compare osseointegration and peri-implant crestal bone resorption in submerged flapless and conventional flap surgery over a 12-month follow-up. MATERIALS AND METHODS: The study used five domestic pigs. Implants were inserted 9 weeks after tooth extraction. Each animal received six implants in the mandible, following a split-mouth design: one side was treated using a flapless technique using mini-incisions, while a flap was raised on the other. The animals were sacrificed at 2 weeks, 1, 3, 6 and 12 months after implant placement. Radiographic images were taken to analyze crestal bone loss, and samples were extracted for histopathological and bone-to-implant contact (BIC) analyses. RESULTS: Significantly, greater crestal bone loss (P = 0.005) was obtained in the flap group compared with the flapless group. The flapless group presented significantly higher percentages of BIC (P < 0.05) at 3, 6 and 12 months compared with the conventional flap group. CONCLUSIONS: Within the limitations of this experimental animal study, it may be concluded that the type of surgery (flap or flapless) affects peri-implant bone preservation and osseointegration of regular platform implants. Flapless surgery is associated with peri-implant crestal bone preservation. Flapless surgery in combination with submerged implants allows higher osseointegration values.

Volumetric analysis of remodelling pattern after ridge preservation comparing use of two types of xenografts. A multicentre randomized clinical trial.

OBJECTIVES: The aim of this randomized clinical trial was to analyse and compare the volumetric changes after ridge preservation procedures using two different biomaterials and to evaluate associations between outcome variables and pristine three-dimensional aspects of the ridges. MATERIALS AND METHODS: Twenty-eight patients subjected to single-tooth alveolar ridge preservation were enrolled in the present multicentre, single-blind, prospective and randomized clinical trial. Fourteen sites were randomly allocated to each experimental group. The experimental sites were grafted with pre-hydrated collagenated cortico-cancellous porcine bone (coll group) or with a cortical porcine bone (cort group) and a collagen membrane; a secondary soft tissue healing was obtained for all experimental sites. Plaster casts were scanned (preoperative, at 1 and 3 months postoperative). Analysis of volumes and areas was performed, and all measured variables were statistically compared. RESULTS: Intragroup analyses at 3 months revealed that when examining changes related to three-dimensional features of remodelling patterns (volume, surfaces, height and shape), the two biomaterials showed similar behaviours with a minor loss in volume and ridge surface. Intergroup analysis at 3-month survey revealed that volume resorption of the coll group (244 mm3 ) was significantly lower (P = 0.0140) than that of the cort group (349 mm3 ). The reduction for basal surface appeared significantly different between the two groups at 1-month survey only (P = 0.0137), while the final basal surface reduction was 4.9 and 12.2 mm2 for coll and cort group, respectively. The superior surface reduction was 40.8 mm2 for coll and 50.7 mm2 for cort group, with no significant difference between the two groups. CONCLUSION: At the 3rd month analysis, coll group showed a significantly lower reduction of ridge volume and a significantly smaller shrinkage of the basal area when compared to the cort group; moreover, the coll group experienced a smaller superior surface shrinkage when compared to the cort group, even though no significance was evaluated.

Bleeding Rate After Tooth Extraction in Patients Under Oral Anticoagulant Therapy.

OBJECTIVES: The aim of this single-cohort prospective study was to evaluate the risk of adverse outcomes after tooth extraction in patients suffering from cardiovascular disorders and under oral anticoagulant therapy with an international normalized ratio within the value of 3.0. METHODS: Two hundred ninety-three patients (mean age of 58.7 years) were enrolled and 560 tooth extractions were performed. Fresh extraction sockets were treated with collagen tablets and sutures. The risk of increased bleeding rate was evaluated for type of drug therapy (acenocoumarol or warfarin), type of cardiovascular diseases, and number of tooth extractions. Level of significance was set at 0.05. RESULTS: The overall bleeding event rate was 6.8%. Among patients who had bleeding events, 4 suffered from valvular disorders, whereas 11 suffered from arrhythmias (8) or cardiomyopathies (3). The remaining 5 patients had a history of cardiomyopathy and arrhythmia.The bleeding events in patients who had more than 2 tooth extractions were significantly higher than those observed in patients who had only 1 tooth extraction (P <0.05). CONCLUSION: Patients who received more than 2 tooth extractions, who were under treatment with acenocoumarol, and who suffered from multiple cardiovascular diseases were at high risk for bleeding events.

Gene Expression of Human Mesenchymal Stem Cells Cultured on Titanium Dental Implant Surfaces.

OBJECTIVE: The study shows how the influence of titanium surfaces on human mesenchymal stem cells differentiates toward osteocytes lineage and how, after growth, on machined titanium disk or etched titanium disk, changes, in gene expression for RUNX1, CTNNB1, SP7, and DLX5. METHODS: Genes were analyzed by means of quantitative real-time polimerase chain reaction. Osseo genic lineage differentiation was also tested by means of the catenin-ß1 immunofluorescence, induced osteoblasts, which represented the internal control. RESULTS: The RUNX1 and SP7 expressions in the induced osteoblasts prove to be different, compared with cells cultured on metallic supports. Moreover, the levels of expression of the runt-related transcription factor 1 and the osterix appeared more down-regulated in cells that grew on a machined titanium surface. In the present experimental model, mRNA expression of DLX5 and CTNNB1 in human mesenchymal stem cells, cultured on each of the titanium surfaces, showed no differences, compared with osteoblast-induced cells. The immunofluorescence scores, for protein expression of beta-catenin in human mesenchymal stem cell treated cells, illustrates significantly improved results with the etched surface. CONCLUSIONS: Present results suggested that different titanium surfaces might induce some differences in terms of gene expression. The only gene analyzed, which proved significant differences between the 2 titanium supports, was SP7; however, the other 3 genes indicating the existence of differences between the 2 titanium groups.

Flap versus flapless procedure for ridge preservation in alveolar extraction sockets: a histological evaluation in a randomized clinical trial.

OBJECTIVE: The aim of this study was to evaluate and compare the histological and histomorphometric features of two different procedures carried out in extraction socket grafting; namely, the flapped and flapless technique. MATERIALS AND METHODS: Patients considered eligible for the study were randomized to receive tooth extraction and ridge preservation with the porcine bone and collagen membrane, with a full thickness mucoperiosteal flap and primary soft tissue closure (control group), or, with a flapless procedure and a secondary soft tissue closure (test group). After 3 months of healing, the surgical re-entry procedure was performed and implants were inserted in the test as well as in the control sites. Bone core samples were harvested from both groups and processed to be observed under light microscopy. Outcome variables were percentages of newly formed bone, residual graft particles and marrow spaces. RESULTS: Thirty-four patients were enrolled in the study. All of the scheduled implants were placed. Histological and histomorphometrical analyses did not report significant differences between the two groups (with P-values ranging from 0.690 to 0.917). The mean percentages of newly formed bone, soft tissues and residual grafted particles were 22.5 and 22.5%, 59.3 and 59.4%, and 18.6 and 18.2% respectively for flap and flapless approach. CONCLUSION: No histological and histomorphometrical differences were observed when comparing the flap and the flapless technique for tooth extraction and socket grafting procedures.

Buccal bone deficiency in fresh extraction sockets: a prospective single cohort study.

OBJECTIVE: The purpose of this prospective single cohort study was to evaluate the use of xenograft and collagen membranes in treating full or partial buccal bone defects of fresh extraction sockets in the esthetic zone. MATERIALS AND METHODS: Thirty-three patients requiring tooth extraction in the anterior maxillary area and showing a complete or partial buccal bone plate deficiency (more than 2 mm) were consecutively enrolled and treated. Corticocancellous porcine bone and platelet-rich fibrin (PRF) with a collagen membrane were used to graft the extraction sockets, and the membranes were left exposed to the oral cavity with a secondary soft tissue healing. The outcome variables were as follows: width of keratinized mucosa, facial soft tissue levels, clinical bone changes (measured with a clinical splint), implant and prosthesis failures, and peri-implant marginal bone changes. RESULTS: All treated sites allowed the placement of implants; the width of keratinized mucosa at the mid-facial aspect showed an increase of 2.3 mm 5 months after the grafting procedure, and its value was 3.2 ± 0.6 mm at 1-year follow-up. The mean values of the facial soft tissue level indicated an increase over time. The bone level showed an improvement of 0.8 ± 0.1 mm and 0.7 ± 0.1 mm at mesial and distal sites, respectively, when compared to the baseline measurements. Finally, in the palatal area, no bone changes were observed. No implant failed during the entire observation period. CONCLUSIONS: Findings from this study showed that xenograft and PRF, used for ridge preservation of the extraction sockets with buccal bone plate dehiscence in the esthetic zone, can be considered effective in repairing bone defects before implant placement. The secondary soft tissue healing over the grafted sockets did not compromise bone formation; moreover, the soft tissue level and the width of keratinized gingiva showed a significant improvement over time.

Posttraumatic use of dental implants immediately after tooth extraction: clinical study.

PURPOSE: Root fracture is a combined injury of cementum, dentin, and pulp. Many of these traumas remain untreated, mistreated, or overtreated. It leads to a more complicated treatment in case of tooth loss. Many different treatment procedures, with a very changeable success rate, have been proposed for years to treat teeth with root fractures. The objective of the following clinical studies was to evaluate the clinical effectiveness of implants placed in fresh extraction sites to treat teeth with horizontal root fracture. METHODS: The study group included 25 patients (15 men and 10 women) between the ages of 20 and 65 years. After an initial examination and a treatment planning, all of the patients underwent periodontal treatment, which was deemed necessary to favor wound healing. All the 25 teeth were extracted because of horizontal root fracture located at the level of the middle third. The second-stage surgery was performed 6 months after the initial procedure. The following clinical parameters, presence or absence of mobility, presence or absence of pain, and presence or absence of suppuration, were evaluated in each patient at 6 and 12 months after implant placement. Radiographs were taken using the standard method to evaluate the marginal bone loss. RESULTS: The healing period was uneventful for all patients. All implants had osseointegrated. After 12 months, patients were asymptomatic and showed no signs of infection or bleeding when probed. CONCLUSIONS: On the basis of this study, implants placed right after tooth extraction are a valid treatment procedure, which induces predictable results as treatment of fractured teeth.

Expression of SP7, RUNX1, DLX5, and CTNNB1 in human mesenchymal stem cells cultured on xenogeneic bone substitute as compared with machined titanium.

PURPOSE: The aim of this research was to investigate the gene expression profile of 4 transcription factors in human mesenchymal stem cells (hMSC) cultured with a xenogeneic bone substitute and a support of machined titanium. MATERIAL AND METHODS: In vitro studies were performed on hMSC cells, which grew in contact with cortical porcine bone and machined titanium disks for 10 days. RNA quantification for genes DLX5, CTNNB1, RUNX1, and SP7 was assessed by quantitative real-time polymerase chain reaction. For cells supported by titanium, immunocytochemistry of osteocalcin (OC) was also performed. RESULTS: In the osteoblast-induced cells (OIC), DLX5, CTNNB1, and RUNX1 were significantly upregulated (+2.38-, +3.51-, and +7.08-fold, respectively), whereas SP7 was downregulated (-26.32-fold). None of the genes seemed to be upregulated or downregulated by the corticocancellous porcine bone. In cells grown on titanium support, DLX5 and RUNX1 were respectively upregulated (+3.12-fold) and downregulated (-2.14-fold). For titanium support, the presence of both catenin beta-1 and OC was verified. CONCLUSION: The 2 genes RUNX1 and SP7 resulted differently expressed in cells cultured on metallic supports if compared with the expression recorded for OIC. An induction of the osteogenic phenotype was observed when cells were cultured on machined titanium, but not on xenogeneic material.