Autologous Tooth Dentin Graft: A Retrospective Study in Humans.

Background and Objectives: The aim of this study is to evaluate the efficacy of an autologous dentin graft, via extracted teeth that are processed into bacteria-free particulate dentin in a Smart dentin grinder and then grafted immediately into alveolus post extraction or into bone deficiencies. Materials and Methods: Ten healthy, partially edentulous patients with some teeth in the mandible were recruited in the study. After their own teeth were grinded, particulate teeth were placed in empty sockets and bone defects after teeth extractions. Furthermore, after three, six, 12 and 24 months, core samples using a 3 mm trephine were obtained. Results: At three months, the particles of grinded tooth were immersed inside a new connective tissue with a small new bone formation (16.3 ± 1.98). At six months, we observed small particles of dentin integrated in new immature bone, without inflammation in the soft tissue (41.1 ± 0.76). At twelve months, we observed a high amount of bone formation surrounding tooth particles (54.5 ± 0.24), and at twenty-four months, new bone, a big structure of bone, was observed with dentin particles (59.4 ± 1.23), statistically different when compared it with at three months. Conclusions: A particulate dentin graft should be considered as an alternative material for sockets' preservation, split technique, and also for sinus lifting. One of the special characteristics after 24 months of evaluation was the high resorption rate and bone replacement without inflammation. This material could be considered as an acceptable biomaterial for different bone defects due to its osteoinductive and osteoconductive properties.

Sinus Augmentation with Simultaneous, Non-Submerged, Implant Placement Using a Minimally Invasive Hydraulic Technique.

Background and objectives: To evaluate whether sinus augmentation, using a minimally invasive implant device, via a non-submerged surgical approach, might negatively influence the outcome. Materials and Methods: A retrospective cohort study was conducted by evaluating patients' files, classifying them into two groups. Fifty patients (22 men 28 women) were included in the study, 25 in each group. The use of an implant device based on residual alveolar ridge height for sinus augmentation, radiographic evaluation, insertion torque, membrane perforation, post-operative healing, and a minimum of 12 months follow-up were evaluated. Results: The mean residual alveolar ridge height was 5.4 mm for the non-submerged group and 4.2 mm for the submerged group. There were no intraoperative or postoperative complications (including membrane perforations). The mean insertion torque was 45 N/cm for the study group and 20 N/cm for the control group. Complete soft tissue healing was observed within three weeks. Mean bone gain height was 8 mm for the study and 9.3 mm for the control group. All implants osseointegrated after 6-9 months of healing time. Mean follow-up was 17.5 months, range 12-36 months. Marginal bone loss at last follow-up was not statistically significantly different: 1 mm in the non-submerged vs. 1.2 mm in the submerged group. Conclusions: Submerged and non-submerged healing following maxillary sinus augmentation was comparable provided residual alveolar ridge height >5 mm and insertion torque >25 N/cm.

Effects of occlusal forces on the peri-implant-bone interface stability.

The occlusal forces and their influence on the initiation of peri-implant bone loss or their relationship with peri-implantitis have created discussion during the past 30 years given the discrepancies observed in clinical, animal, and finite element analysis studies. Beyond these contradictions, in the case of an osseointegrated implant, the occlusal forces can influence the implant-bone interface and the cells responsible for the bone remodeling in different ways that may result in the maintenance or loss of the osseointegration. This comprehensive review focuses on the information available about the forces transmitted through the implant-crown system to the implant-bone interface and the mechano-transduction phenomena responsible for the bone cells' behavior and their interactions. Knowledge of the basic molecular biology of the peri-implant bone would help clinicians to understand the complex phenomenon of occlusal forces and their effects on the implant-bone interface, and would allow better control of the negative effects of mechanical stresses, leading to therapy with fewer risks and complications.

Correction to: Sinus augmentation analysis of the gradient of graft consolidation: a split-mouth histomorphometric study.

Figure 1 was reused with permission from "Wiley", the publisher of a previous article by the same authors, DOI:10.1111/cid.12518.

Sinus augmentation analysis of the gradient of graft consolidation: a split-mouth histomorphometric study.

OBJECTIVE: The aim of this study was to histomorphometrically test the hypothesis that graft consolidation originates from the sinus floor. MATERIALS AND METHODS: This prospective, randomized split-mouth study investigated patients undergoing bilateral maxillary lateral sinus floor augmentation using either freeze-dried bone allografts (FDBAs) or biphasic calcium phosphate (BCP) bone substitute. Apico-coronal core biopsies were harvested during implant placement 9 months after sinus floor augmentation, processed for histological observation, and measured histomorphometrically. RESULTS: Biopsies were taken from 26 bilateral sites in 13 patients. The density of new bone (NB) decreased with increasing distance from the sinus floor. The percentage mean surface of NB ranged from 31 ± 9.5% at 2 mm from the sinus floor (G1) to 27.7 ± 11.2% at 4 mm (G2) for the FDBA specimens and from 30.0 ± 11.0% at G1 to 23.5 ± 9.9% at G2 for the BCP specimens. Evaluation of the residual graft particle (GP) area alone as a function of distance from the floor revealed a clear inverse gradient of 7.1 ± 6.6 to 9.1 ± 10.3 between G1 and G2 for the FDBA allografts, with the same tendency for the BCP alloplasts (21.9 ± 9.9 to 27.7 ± 6.6, respectively). CONCLUSION: Our results support the concept that osteogenesis initiates in regions proximal to the bony walls of the maxillary sinus and may be enhanced by them. CLINICAL RELEVANCE: The nature of the grafting material had a greater influence on the degree of NB formation in regions distant from the native walls where there is reduced inherent osteogenic potential.

Correction to: Influence of surface treatment on osseointegration of dental implants: histological, histomorphometric and radiological analysis in vivo.

Dear Professor Dr. Matthias Hannig. Editor-in-Chief Clinical Oral Investigations. Following the publication of our paper by Calvo Guirado et al, 2015 [1] in Clinical Oral Investigations, it came to light that a certain part of the text at the materials and methods and results sections were similar.

Influence of the implant diameter and bone quality on the primary stability of porous tantalum trabecular metal dental implants: an in vitro biomechanical study.

OBJECTIVES: The aim of this study was to evaluate the primary, initial stability of Porous Tantalum Trabecular Metal™ implants (TM) compared with Tapered Screw Vent® implants (TSV) with different diameters, inserted in two bone densities. METHODS: A total of 160 implants (80 TM and 80 TSV) with narrow (3.7 mm) and conventional (4.1 mm) diameters and the same length (10 mm) were placed in artificial bone blocks representing bone qualities II and IV. The implant stability was evaluated by insertion torque (IT) and Resonance Frequency Analysis. Statistical analysis was performed with non-parametric Kruskal-Wallis test with Dunn post-test for the differences between groups. RESULTS: The results showed higher ISQ values in dense bone compared with soft bone for all the groups (P < 0.05). Conventional-diameter implants (TSV and TM) showed higher ISQ and IT values compared with narrow implants (TSV and TM) in dense and soft bone (P < 0.05). Tapered TSV implants showed higher stability in soft bone compared with TM implants (P < 0.05). In dense bone, differences were not observed between narrow TSV 3.7 mm and TM 3.7 mm implants (P > 0.05). CONCLUSIONS: Within the limitations of this study, it can be concluded: In dense bone blocks, the wider diameter implants are more stable than narrow implants. In soft bone blocks, the tapered TSV implants are more stable than TM implants.

Dental implant surgery in patients in treatment by dabigatran.

OBJECTIVES: The aim of this study was to evaluate the incidence of bleeding complications after dental implant placement in patients in treatment by the oral anticoagulant dabigatran following a specific protocol. MATERIAL AND METHODS: Seventy-one patients were divided into two groups: 29 had been taking dabigatran for over 6 months (150 mg orally every 12 h) before implant surgery (dabigatran group) and a control group consisting of 42 healthy subjects. Patients were treated in an outpatient setting. All subjects received dental implants in different positions, dabigatran group patients 12 h after the last dose of dabigatran. Nonabsorbable sutures were used and patients were given gauzes impregnated with tranexamic acid 5% to bite on for 30-60 min. Dabigatran patients resumed medication 8 h after the procedure, resuming usual dosage (every 12 h) the day after surgery. RESULTS: Two dabigatran patients and two control patients presented slight bleeding the day after surgery. Bleeding was managed with gauzes impregnated with tranexamic acid. No statistically significant differences (P = 0.542) were found in relation to bleeding episodes between the groups, with a relative risk of 0.675 based on the pooled groups and a 95% confidence interval of 0.090-5.088. CONCLUSIONS: Dental implant surgery in patients taking dabigatran can be performed safely providing 12 h have passed since the last dose and local hemostatic measures are applied. Normal dosage can be resumed 8 h after implant surgery.

Crestal bone loss around submerged and non-submerged implants during the osseointegration phase with different healing abutment designs: a randomized prospective clinical study.

OBJECTIVE: To evaluate peri-implant crestal bone loss during the osseointegration period, comparing submerged and non-submerged implants with healing abutments of different design. MATERIALS AND METHODS: A total of 90 Avinent®  dental implants (Avinent Implant System, Barcelona, Spain) were placed in 90 patients. All were sited in the posterior mandibular zone to replace teeth 3.6 or 4.6. Patients were divided randomly into three groups: submerged (n = 30), non-submerged with anatomical healing abutment (n = 30), and non-submerged with esthetic healing abutment (n = 30). Peri-implant crestal bone loss was evaluated in intraoral radiographs taken at baseline, 1, and 3 months after implant placement. RESULTS: Peri-implant crestal bone loss at the end of the (3-month) osseointegration period was lowest in the submerged group (0.11 ± 0.14 mm), followed by the esthetic non-submerged group (0.15 ± 0.06 mm), but without statistically significant difference between these groups (P = 0.234). The greatest bone loss was produced in the non-submerged group with anatomical healing abutments (0.37 ± 0.12 mm), with significant differences between this group and the other two (P < 0.001). CONCLUSIONS: On the basis of these findings, bone resorption during the osseointegration period using the non-submerged technique varied significantly depending on the morphology of the healing abutment used. The non-submerged technique with an esthetic healing post-produced an equally predictable outcome compared with the submerged technique.

The influence of drill length and irrigation system on heat production during osteotomy preparation for dental implants: an ex vivo study.

OBJECTIVE: This study aimed to measure the influence of drill length and irrigation system on heat production during osteotomy preparation for dental implants using bovine bone rib as experimental model. MATERIALS AND METHODS: Three groups were created: Group 1: drilling with three consecutive burs with double irrigation (internal and external) for a 4.0 mm conical implant; and Group 2 and Group 3: drilling with three consecutive burs with external irrigation for a 4.1 mm cylindrical implant and for a 4.3 mm conical implant, respectively. Four lengths were tested: 10, 12, 14 and 16 mm; in site prepared on bovine ribs using a surgical unit linked to a testing device, to standardize and simulate implant drilling procedures. Bone temperature variations were recorded using three thermocouples in different positions as of the crestal bone: 2 mm, position (p1); 7 mm, position 2 (p2); and 12 mm, position 3 (p3). RESULTS: The highest temperature changes were invariably recorded during the process of withdrawal. Significantly lower temperature changes (P < 0.02) could be recorded at maximum drilling depths during the shearing process regardless of drilling depth or irrigation method. Double irrigation was associated with significantly lower temperatures compared with external irrigation by the use of implant drills (P < 0.01). CONCLUSIONS: Within the limitations of this ex vivo study was possible concluded that the use a double irrigation system in multiple conventional drill for osteotomy can decrease the heat generation when increase the drill length.

Clinical and radiographic evaluation of implants placed by means of inferior alveolar nerve lateralization: a 5-year follow-up study.

OBJECTIVE: To evaluate clinical and radiological responses of implants placed in combination with inferior alveolar nerve lateralization, analyzing survival and success rates over 5 years functional loading. MATERIALS AND METHODS: This prospective, longitudinal, single-center study recruited 40 patients with mandibular atrophy in the posterior sectors, who underwent lateralization of the inferior alveolar nerve. Three months after surgery and implant placement, the implants were loaded by means of screw-retained implant-supported partial prostheses or fixed complete prostheses. Clinical and radiographic examinations were performed immediately after implant placement and at 12, 24, 36, 48 and 60-month follow-up visits. RESULTS: The 40 patients received a total of 129 implants (Phibo TSA™ , Phibo Dental Solutions, Sentmenat, Barcelona, Spain). Two implants were lost in the first month after surgery, generating an implant cumulative survival rate (CSR) of 98.44%. The success rate after 5 years of loading was 98.44%. No intra-operative or postoperative soft tissue or prosthetic complications occurred during the 5-year follow-up. CONCLUSIONS: Inferior alveolar nerve lateralization performed to allow placement of (Phibo TSA™ ) implants in patients with mandibular atrophy obtained predictable clinical and radiological results over five years of functional loading.

Peri-implant bone loss clinical and radiographic evaluation around rough neck and microthread implants: a 5-year study.

OBJECTIVE: To evaluate marginal bone loss over 5 years around microthreaded implants placed in the maxillary anterior/esthetic zone and immediate restored with non-occlusal loading. MATERIALS AND METHODS: Seventy-one implants (with microthreads up to the platform-rough surface body and neck, internal connection and platform switching) were placed in healed bone in the maxillary arches of 30 men and 23 women (mean age 37.85 ± 7.09 years, range 27-60). All subjects had at least 3 mm of soft tissue to allow the establishment of adequate biologic width and to reduce bone resorption. Each patient received a provisional restoration immediately after implant placement with slight occlusal contact. Mesial and distal bone height was evaluated using digital radiography on the day following implant placement (baseline) and after 1, 2, 3, 4 and 5 years. Primary stability was measured with resonance frequency analysis. RESULTS: No implants failed, resulting in a cumulative survival rate of 100% after 3 years. Marginal bone loss from implant collar to bone crest measured at baseline (peri-implant bone defect at the fresh extraction socket) and after 5 years was 0.90 mm ± 0.26 mm. Mesial and distal site crestal bone loss ranged from 3.42 ± 1.2 mm at baseline to 3.51 ± 1.5 mm after 5 years and from 3.38 ± 0.9 mm at baseline to 3.49 ± 0.9 mm after 5 years, respectively (P = 0.086). CONCLUSIONS: The results of this study showed limited implant crestal bone loss 0.90 mm ± 0.26 mm and 100% of implant survival rate at 5-year follow-up of immediate restored implants with rough surface neck and microthreads.

Retracted: Histologic evaluation of new bone in post-extraction sockets induced by melatonin and apigenin: an experimental study in American fox hound dogs.

OBJECTIVE: The aim of this study was to evaluate the effect of topical applications of melatonin and apigenin (4',5,7-trihydroxyflavone) on new bone formation in post-extraction sockets after 30, 60 and 90 days. MATERIALS AND METHODS: Six American fox hounds were used in the study, extracting mandibular premolars (P2, P3 and P4) and first molar (M1). Melatonin or apigenin impregnated in collagen sponges were applied at P3, P4 and M1 sites in both hemimandibles; P2 sites were used as control sites. Bone biopsies were taken at 30, 60 and 90 days and stained with hematoxylin-eosin. RESULTS: At 30 days, a higher percentage of immature bone was observed in the control group (58.11 ± 1.76%) than in the apigenin (34.11 ± 1.02%) and melatonin groups (24.9 ± 0.14%) with significant differences between the three groups (P < 0.05). At 60 days, results were significantly better at melatonin sites (10.34 ± 1.09%) than apigenin (19.22 ± 0.35%) and control sites (36.7 ± 1.11%) (P < 0.05). At 90 days, immature bone percentages were similar for all groups. New bone formation was higher in melatonin group (79.56 ± 1.9%) than apigenin (68.89 ± 1.5%) and control group (58.87 ± 0.12%). CONCLUSIONS: Topical applications of either melatonin or apigenin have a potential to accelerate bone tissue in early healing stages; melatonin was seen to have stimulated bone maturation to a greater extent at the 60 days of follow-up.

Effects on the osseointegration of titanium implants incorporating calcium-magnesium: a resonance frequency and histomorphometric analysis in rabbit tibia.

OBJECTIVE: This study assessed the bone formation around titanium surface incorporating the calcium-magnesium (CaMg) deposited by blasted in rabbit tibia bone to determine whether this surface would further enhance bone healing compared with commercially available implant surface. MATERIAL AND METHODS: The deposition of CaMg on the titanium SLA surface were obtained by blasting formed the experimental group (EX group), while implants with traditional SLA surface were used as control group (CO group), in this study. Fifty cylindrical threaded implants with a length of 8 mm were used (P = 25 per group). Five implants of each group were used to surface characterization by scanning electron microscopy, energy dispersive spectrometry, and optical profilometry. Ten New Zealand white rabbits received 40 implants (n = 20 per group). Resonance frequency analysis was performed three times (0, 4, and 6 weeks). Histomorphometric analysis was performed 4 and 6 weeks after implantation. Statistical significance was set at P < 0.05. RESULTS: Blasted CaMg deposition on SLA implant surface displayed almost identical surface morphologies and R(a) values at the micron scale. In comparing the implant stability quotient at the three time points, highly significant statistic differences were found (P < 0.001). Histomorphological analysis showed higher degrees of bone organization in the samples of test implant surfaces at both implantation times. CONCLUSION: Within the limitations of this study, the results indicate that the deposition of CaMg on the SLA titanium surface may be effective in enhancing the osseointegration of moderately rough grit-blasted implants by increasing the degree of bone-implant contact.

Retracted: A new cervical implant design compared with standard design in order to increase peri-implant hard and soft tissue behavior: histomorphometric and histological study in dogs.

OBJECTIVE: The aim of this study was to evaluate a new design of the cervical portion of dental implant with the objective to increase the volume of peri-implant tissues in the crestal area. MATERIALS AND METHODS: Forty-eight tapered dental titanium implants with internal conical connection were implanted in healed alveolar sites of six dogs. Twenty-four conventional implants design (C1 implant) formed the control group, and 24 new implant design (V3 implant) formed the test group. The groups were randomized. Histological, histomorphometric, and implant stability quotient were performed. After 12 weeks of healing period, histomorphometric analyses of the specimens were carried out to measure the crestal bone level values and the tissue thickness in the cervical implant portion. The data were compared using statistical tests (α = 5%). RESULTS: The mean of the measurements in the buccal and lingual aspects measured of crestal bone level was 0.31 ± 0.24 mm and 0.30 ± 0.19 mm in the control group, respectively, and 0.71 ± 0.28 and 0.42 ± 0.30 mm in the test group, respectively, whereas the mean of the tissue thickness was 1.63 ± 0.33 mm and 2.04 ± 0.23 mm in the control group, respectively, and 2.11 ± 0.35 mm and 2.51 ± 0.41 mm in the test group. CONCLUSIONS: Within the limitations of this study, our findings suggest that more thickness of peri-implant hard and soft tissues may be expected in this new implant design. However, the control group with traditional implant design was found to have more height values of the crestal bone compared with new V3 implants.

Biological effects of compressive forces exerted on particulate bone grafts during socket preservation: animal study.

OBJECTIVES: To compare different compressive forces exerted on a particulate graft material during socket preservation and their effects on bone regeneration. MATERIAL AND METHODS: Six male dogs were used. The second, third, and fourth premolars, and the first molar were extracted bilaterally at the lower jaws. A particulate synthetic biphasic grafting material (60% HA and 40% ß-tricalcium phosphate) was used. Three different standardized compressive forces were applied randomly during the socket preservation. The sample was divided into four experimental groups Test A (10 g), Test B (50 g), Test C (200 g), and Control (empty sockets). Collagen membranes were placed, and primary closure was obtained. Two months after the surgery the animals were sacrificed, and histomorphometric analysis of non-decalcified samples was performed at the coronal, middle, and apical thirds. RESULTS: Grafted sockets resulted in higher bony contour (3 ± 0.43 mm2 ; P < 0.05). The particles penetrated up to the apical third in the group C but not in the other test groups and controls (P < 0.05). The percentage of new bone were higher at the coronal and apical thirds for Controls and group C compared to A and B groups (P < 0.05). The residual graft was higher for group C (53 ± 1.4%), followed by group B (45 ± 3.1%) and group A (35 ± 1.9%; P < 0.05). The percentages of connective tissue were higher at the middle third without differences between groups (P > 0.05). CONCLUSIONS: Within the limitations of this experimental animal study, it might be concluded that grafted sockets compressed with 200 g force will have higher bony contours; higher compressive forces facilitate the penetration of the particulate graft material into the apical area of the socket and results in more bone formation at the coronal, middle, and apical thirds.

A comparative evaluation between aluminium and titanium dioxide microparticles for blasting the surface titanium dental implants: an experimental study in rabbits.

OBJECTIVE: The aim of this study was to compare, through biomechanical and histological analysis, the aluminium (AlO2) and titanium dioxide (TiO2) microparticles for blasting during the sandblasting acid surface treatment in titanium dental implants using a rabbit tibia model. MATERIALS AND METHODS: Forty-eight commercially available titanium dental implants were divided into two test groups (n = 24 per group): implants with surface treated by AlO2 followed by acid etching as control group (Con group) and implants with surface treated by TiO2 followed by acid etching as test group (Test group). The implants were randomly installed in both tibias of eight rabbits and block samples were removed 4 and 8 weeks after implantation. Resonance Frequency Analyses were performed immediately after the implantation and at 8 weeks. Twelve implants of each group were removed to measure the reverse torque. The remaining implants were used for histological analysis. The data were compared using statistical tests (α = 0.05). RESULTS: In comparing the implant stability quotient at the two time points, no significant statistical differences were found (P > 0.05), as well as in the removal torque test at 8 weeks after implant placement, no found significant difference between the two groups was tested. Histomorphometric analysis showed a high degree of bone organization in all samples with no significant difference between groups in the bone-to-implant contact (P > 0.05). CONCLUSION: Within the limitations of this study, the results indicate that the media of surface blasting (AlO2 or TiO2 microparticles) did not show significant differences in the tested parameters for assessing the osseointegration of the implants.

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.

Randomized clinical study of the peri-implant healing to hydrophilic and hydrophobic implant surfaces in patients receiving anticoagulants.

OBJECTIVES: To compare the peri-implant bone healing between TiZr implants with hydrophilic SLActive and hydrophobic SLA implant surface in patients receiving anticoagulants, to assess the implant survival and success rate, as well as to evaluate whether small-diameter TiZr implants could be used in patients on OAT in order to avoid augmentation procedures. MATERIAL AND METHODS: A total of 80 small-diameter tissue-level TiZr implants with SLActive and SLA surfaces were placed in 20 anticoagulated patients, following the "split-mouth" study design. Implant stability was measured up to the third postoperative month by resonance frequency measurements (RFA). One-year implant survival and success rate were evaluated. RESULTS: After one year, 100% implant survival and success rate were observed. A significant decrease in ISQ comparing to baseline values was noted in the SLActive group from the first postoperative week, and in the SLA group, from the 3rd week after the surgery. In both groups, a statistically significant decline in ISQ was observed between second and third postoperative week. No significant differences in ISQ values between SLActive and SLA implants were noted, at any time point. CONCLUSIONS: Titanium-zirconium small-diameter implants with SLActive and SLA surface predictably achieve and maintain adequate bone tissue integration in patients receiving anticoagulants. OAT appears to influence the bone healing events resulting in lower ISQ in the end of 3-month period in comparison with baseline values, although without compromising implant stability.