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Objectives The primary aim of the present article was to review the effect and the clinical significance of abutment dis- and reconnection on the peri-implant marginal bone levels. Materials and methods English articles published from 2009 to April 2019 were identified on the MEDLINE, Cochrane Library, and PubMed databases, according to the PRISMA guidelines. Comparative in vivo studies on humans were included. Results A total of 4 studies with different levels of bias were included in this review. A significant heterogeneity of the reported data was observed, which limited the comparison of the findings. The only parameter that was homogenous throughout all 4 studies was the marginal bone level measurement. Conclusion Within the limitations of the present review, it can be suggested that minimizing the number of abutment dis- and reconnections would be beneficial to ensure minimal disruption to the peri-implant tissue and marginal bone level. However, the clinical significance of the marginal bone level changes is still inconclusive.

The aim of the present study was to review the effectiveness, side effects, and patient acceptance of different concentrations and formulation of chlorhexidine-based mouthwashes used after periodontal and implant surgery.The PRISMA guideline was adopted in the search strategy using electronic databases PubMed and MEDLINE to identify randomized and case-control prospective studies on humans written in English language and published up to September 2017.A total of 10 articles were selected for a total of 344 patients. Because of the significant heterogeneity of the outcome measures, meta-analysis was not performed, and the data were summarized in a table. A positive relationship between the use of chlorhexidine and reduction of plaque was found, demonstrating the effectiveness of the substance in terms of antisepsis and decrease of inflammation after periodontal and implant surgery.Chlorhexidine is recognized as the primary agent for plaque control and the gold standard in preventing infection, although the presence of largely known side effects would affect patient compliance. Future research should be directed at finding chlorhexidine formulation with negligible adverse effects, without compromising or even increasing its effectiveness as the antiseptics and antiplaque agent.

Objective: A wide range of surgical techniques are available for maxillary sinus augmentation. This review aimed to determine which techniques have achieved the highest success rates and so offer the greatest predictability. Materials and methods: A systematic literature review was performed using the PubMed, MEDLINE, and Scopus databases, identifying clinical trials that assessed different surgical techniques for maxillary sinus augmentation, and registered the success rates of subsequent implant placement. Results: A total of 40 articles described clinical studies involving different maxillary sinus augmentation procedures with follow-up periods of at least 6 months after dental implant placement. Implant success rates varied between 94% and 100% during the follow-up periods. Conclusion: A wide variety of clinical techniques are available for maxillary sinus augmentation; the choice of the technique will depend chiefly on the characteristics of the edentulous site, which will permit or prevent the placement of the implant at the moment of sinus augmentation surgery. Sin financiación 1.107 JCR Q3, 67/790 Dentistry, Oral Surgery & Medicine UEM

This study aimed at a histologic and histomorphometric analysis of the periimplant tissues and bone-titanium interface reactions in successfully osseointegrated, clinically stable, and immobile human titanium dental implants retrieved after a long loading period.In the last 30 months (2013-2015), 21 implants, retrieved from individuals for different causes after a loading period ranging from 4 to 20 years, were sent to the Implant Retrieval Center, University of Chieti-Pescara, Italy. In 4 cases, almost all the bone had been lost during the retrieval, whereas in the remaining 17 cases, mineralized bone was still present.Around the majority of the implants, mature compact bone with few marrow spaces was found. The trabecular bone, constituted by a few thin bone trabeculae, was in a periimplant location around only a few implants. A high percentage of bone-implant contact (BIC) (comprised between 32 ± 4.1% and 83 ± 2.9%) was present. In almost all implants, the space within the threads was almost completely filled by compact lamellar bone or by a thin layer of bone. Close and tight contact between bone and implant surface was observed in all specimens with no gaps or connective tissue at the interface.All implants appeared to be well integrated in the surrounding mineralized bone, and all of them showed adequate bone-to-implant contact percentages.

OBJECTIVE To histologically evaluate hard and soft tissues adaptation at screw-shaped devices installed at recipient sites in the distal segments of the alveolar edentulous ridge prepared with a buccal bone width of 1 or 2 mm. MATERIAL AND METHODS Sixteen volunteers received 2 nonsubmerged titanium implants each; after 3 months, biopsies were obtained and processed for histology. The distances between implant shoulder (IS), top of the bony crest (C), coronal level of osseointegration (B), peri-implant mucosa (PM), and apical extension of the junctional epithelium (aJE) were measured. RESULTS There were no significant statistically differences between test and control sites regarding IS-C, IS-B, PM-IS, PM-B, PM-aJE, aJE-B measurements. The horizontal bone resorption 1 mm below IS was 0.3 ± 0.3 and 1.0 ± 0.7 mm at the test and control sites, respectively. This difference was statistically significant. CONCLUSIONS Similar hard and soft tissues dimensions were observed in both groups. However, a higher horizontal bone resorption was seen at the control sites. Nonsubmerged implant installation should be performed when a 1 mm buccal bony crest width is present so as to limit the horizontal bone resorption.

The aim of this multicenter human clinical trial was to radiographically evaluate the marginal bone loss and to assess implant survival rate in patients treated using 2 different implant systems (Bio-Plant and Tuber-Plant) after 10 years of loading.Ninety-seven patients were selected, and 160 implants were inserted (72 Bio-Plant and 88 Tuber-Plant). Ten years later, 20 patients were lost at follow-up and 77 patients (126 implants; 67 Bio-Plant and 59 Tuber-Plant) were recalled. After 10-year, the periimplant bone resorption was significantly lower (P = 0.0039) for Tuber-Plant (0.74 ± 0.12 mm) than for Bio-Plant (1.31 ± 0.09 mm). The cumulative survival rate was 99.11%.Both implant systems demonstrated to be suitable for a long-term successful rehabilitation because of stable marginal bone levels and high survival rates after 10 years of functional loading.

Due to its antioxidant properties and its ability to detoxify free radicals, melatonin may interfere in the function of osteoclasts and thereby inhibit bone resorption. This inhibition of bone resorption may be enhanced by a reaction of indolamine in osteoclastogenesis and this may contribute to certain benefits in implantology.This systematic literature review on the use of melatonin in implant dentistry aims to provide guidelines for clinicians.PubMed, Science Direct, ISI Web of Knowledge, and the Cochrane base databases were used to identify articles published between 1999 and 2013 on melatonin use in implant dentistry. Ten articles were selected consisting of 9 animal research studies and 1 review article, involving 60 Beagle dogs, 57 rats, and 30 rabbits and a total of 352 implants.Melatonin, which is released into the saliva, has important implications in the oral cavity. To achieve dental implant stability, osseointegration involves a cascade of protein and cell apposition, vascular invasion, bone formation, and maturation. This process may be accelerated by local delivery of growth-promoting factors, as occurs with the topical application of melatonin over the implant surface.The experimental evidence suggests that topical applications of melatonin may be useful in oral surgery and implant dentistry, increasing bone-to-implant contact values and new bone formation, and so improving the success and long-term survival of implant treatments.

Purpose The aim of this study was to systematically review the literature on implant placement in sites of previously failed implants and to assess survival and success rates of the replacement implants to investigate the effectiveness of the procedure. Materials and methods MEDLINE and Cochrane Oral Health Group databases were used to identify articles published between 1985 and 2011. Six articles were selected for a total of 334 patients (338 implants). Results The survival rate ranged from 71% to 100%. The survival rate for implants placed for the second time (third attempt) in the sites of previously failed implants was 83.75%. No studies included in this review reported the cumulative success rate except for the prospective one, which reported a 93.7% success rate. The main limitations of the present systematic review have been the scarce number of patients and implants in the analyzed studies and the lack of large well-designed case-control long-term trials. Conclusions Survival rates of implants placed in the areas of previously failed implants are low, although they should not discourage clinicians from a second or even a third attempt.

Analysis of human-retrieved implants provides a unique opportunity to evaluate osseointegration processes. There is evidence that faster bone apposition is present at textured surfaces, with a very high success percentage. Aim of the present retrospective analysis was an evaluation of 14 human retrieved from humans implants with a wettable, highly hydrophilic, microstructured surface.The archives of the Implant Retrieval Center of the Dental School, University of Chieti-Pescara, Italy, were searched, and a total of 14 implants FRIADENT plus surface (Dentsply Implants Manufacturing GmbH, Mannheim, Germany) retrieved after a loading period comprised between 4 and 8 weeks were found.Around all implants, newly formed bone was found in direct contact with the implant surface, with no connective fibrous tissue found at the interface. In all implants, no epithelial downgrowth was present. A very high bone-to-implant contact percentage was found.The efficacy of dental implants is related to biological and biomechanical stability and to the integration between the bone and the implant. This integration plays the key role in the fixation and anchoring of the implants.

The anatomical remodeling technique (ART) was proposed to place postextraction implants with the aid of specific osteotomes. This study is a clinical and radiographic evaluation with 10-year follow-up of anterior postextraction single implants placed with the ART and immediately restored.Thirty-five patients, with a hopeless tooth in the anterior maxilla, were included in the study and 35 implants were inserted according to the ART. Clinical and radiographic evaluations were performed at baseline (T0), after 6 (T1) and 14 months (T2), 4 years after surgery (T3) and every other year up to the 10-year follow-up (T4, T5, and T6). Implant success, survival, and failure rates were evaluated according to the International Congress of Oral Implantologists Pisa Consensus Conference criteria.Twenty-nine patients and 29 implants were available for the 10-year data analysis. After 10 years, the accumulated mean marginal bone loss was 2.69 ± 0.42 mm. The cumulative survival rate of the implants was 100%.Immediately loaded postextractive implants, placed according to the ART, have been proved to be a predictable method to rehabilitate single tooth in the anterior maxilla.

To evaluate, in vitro, the leakage observed in internal hexagon and Morse taper implant-abutment connections.Ten specimens with internal hexagon and 10 with Cone Morse connection were used. The inner parts of 5 implants, per group, were inoculated with Pseudomonas aeruginosa (PS) suspension and 5 implants, per group, with Aggregatibacter actinomycetemcomitans (AA). The penetration of bacterial suspension into the surrounding solution was determined by observation of turbidity of the broth.In the internal hexagon implants, bacterial contamination was found in 2 of 5 implant-abutment assemblies seeded with the PS, and in the assemblies seeded with AA, the contamination was found in 3 samples, with a total of leaked assemblies in this group in 5 of 10. In the Cone Morse implants, bacterial contamination was found in 2 of 5 implant-abutment assemblies seeded with the PS, whereas in the assemblies seeded with AA, no contamination was found, with a total of leaked assemblies in 2 of 10.The data support a not significantly higher permeability to bacterial leakage and a lower infiltration rate of screw-retained abutment connections when compared to Cone Morse taper internal connections.

The aim of the present study was to perform a comparative histological and immunohistochemical evaluation of microvessel density, vascular endothelial growth factor, and nitric oxide synthase (NOS) expression in sinus augmentation using autologous bone alone or in combination with equine bone.Sixteen patients underwent sinus augmentation with autologous bone and a 50:50 mixture of autologous and equine bone. Control cores were harvested from preexisting nonaugmented bone under the sinus floor. The specimens were processed for immunohistochemistry.The greatest values of microvessel density were found in the sites grafted with autologous bone with significant differences between control versus autologous group (P0.01) and control versus autologous + equine group (P0.01). The higher and lower intensities of vascular endothelial growth factor and NOS3 expression were prevalent in the sites grafted with autologous bone with significant differences with the controls (P0.05). No significant differences (P0.05) were found in the NOS1 expression among the groups.The results obtained showed that the mixture of autologous and equine bone was biocompatible, and its use was associated with new blood vessels ingrowth during healing, which has been found to be extremely important for bone formation.

PURPOSE The aim of this study was to assess the fractal dimension (Df) of disks with 3 different surface topographies. MATERIALS AND METHODS Thirty disk-shaped samples (10 × 2 mm) with 3 different surface topographies (Dental Tech, Misinto, Italy) were analyzed by scanning electron microscopy: group A, machined surface; group B, titanium plasma-spray surface; group C, acid-etched and sandblasted surface (Blasted Wrinkled Surface). RESULTS The amplitude roughness parameter (Sa) of the machined surfaces was 0.6 μm, while the developed surface area ratio (Sdr) was 14%; for the titanium plasma-spray surfaces, the values were, respectively, 5.3 μm and 97%, and for the Blasted Wrinkled Surfaces, 1.5 μm and 63%. Images at 1.000, 20.000, and 50.000 magnifications were processed for quantitative analysis of Df using the box-counting method. At 1.000×, Df for group A, B, and C was 1.86, 1.80, and 1.81, respectively; at 20.000×, Df for group A, B, and C was 1.85, 1.71, 1.58, respectively; and at 50.000×, Df was 1.83, 1.61, and 1.51 for A, B, and C groups. Statistically significant differences were found for Df values. CONCLUSIONS Df provides not only an index of roughness size values but also a measure of roughness spatial organization; therefore, it could be a promising method to differentiate between rough surfaces capable of supporting osseointegration.

Purpose: Immediate loading of dental implants inserted into fresh postextraction sites has recently been proposed as a novel but challenging surgical approach. However, histological evidence and comparative data are still missing. The aim of this study was an histological and histomorphometrical comparison of submerged and immediately loaded dental implants with a new modified acid etched surface inserted into postextraction sites of nonhuman primates. Materials and Method: Thirty-two implants were placed in postextraction sockets of 4 adult Chacma Baboons (papio ursinus). Each baboon received 8 implants: 4 submerged and 4 immediately loaded. The implants were retrieved after 90 days of healing with a 4-mm trephine bur and processed for histology and histomorphometry. Results: The bone-to-implant contact percentage in the submerged and immediate loaded implants was 86.02% and 86.85%, respectively, with no statistically significant differences. In the immediately loaded implants a greater amount of ongoing remodeling was observed. Conclusions: Immediate loading seemed to be a valid alternative to conventional technique when a implant is inserted into postextraction sockets. Further comparative studies on a greater number of samples are necessary to confirm our findings.

Purpose: The aim of the present study, in man, was an histologic and histomorphometric analysis of the peri-implant tissues in 3 immediately loaded screw implants retrieved, because of fracture, after a 3 year loading period. Results: Mineralized tissue was present at the interface of all implants. The mean bone to implant contact percentage for the 3 implants was 56.3% ± 5%. The histologic and histomorphometric data showed that mineralized tissues can be obtained in immediately loaded screw implants and that these mineralized tissues are maintained over a period of 3 years. The response of the osseous tissue was not disturbed by the stresses and strains transmitted at the interface. Conclusion: A high primary stability, obtained by the large threads of the screw-shaped implant, was probably a key factor in the long-term maintenance of a mineralized bone interface. The primary stability helps to resist micromotion, i.e., the relative movements between the implant surface and surrounding bone during functional loading.

Background: Calcium sulfate is a simple, biocompatible material with a very long, safe clinical history in several different fields of medicine. It is a rapidly resorbing material that leaves behind calcium phosphate lattice, which promotes bone regeneration. Objective: The aim of this study was a histological and ultrastructural evaluation of the tissues in a peri-implant site regenerated with calcium sulfate. Materials and Methods: The specimens were processed for observation under light and transmission electron microscopes. Results: In light microscopy, trabecular bone was present. No remnants of calcium sulfate were present. Transmission electron microscopy showed, in the areas of the interface with the implant surface, features of mature bone with many osteocytes. An amorphous layer and/or osteoid seam separated this mature bone from the metal surface. Conclusion: The results confirm the high biocompatibility and rapid resorption of calcium sulfate.

Implant failures could be due to biological or mechanical factors, which also include fracture of the fixture. The present report presents a case of a single fractured implant placed in the left mandibular molar region. Since the residual portion of the fixture was perfectly osseointegrated with no signs of peri-implantitis, and in direct contact with the roof of the inferior alveolar nerve canal, it was decided to treat the patient with a short implant positioned on top of the fractured, and not removing the fractured implant. Clinical and radiographical follow-up was performed for 12 months after loading. Periimplant soft tissues healing and implant osseointegration were achieved 6 months after implant placement; at the end of the follow-up a periimplant bone remodeling of 0.3 mm was observed. In conclusion, short implants could be taken into consideration as a treatment option in cases of nonremovable implants and sufficient residual bone height.

Objective: Rehabilitation of the edentulous posterior maxilla with dental implants can be difficult because of insufficient bone volume caused by pneumatization of the maxillary sinus and crestal bone resorption. Different biomaterials have been used for sinus augmentation. The aim of the study was to compare different materials in maxillary sinus augmentation in man. Methods: A total of 94 patients participated in this study. Inclusion criteria were maxillary partial (unilateral or bilateral) edentulism involving the premolar/molar areas, and the presence of 3–5-mm crestal bone between the sinus floor and alveolar ridge. A total of 362 implants were inserted. There were 9 biomaterials used in the sinus augmentation procedures. Each patient underwent 1 biopsy after 6 months. A total of 144 specimens were retrieved. Results: None of the 94 patients had complications. All implants were stable, and x-ray examination showed dense bone around the implants. Mean follow-up was 4 years. There were 7 implants that failed. Histologic resultsshowed that almost all the particles of the different biomaterials (i.e., autologous bone, demineralized freeze-dried bone allograft Biocoral® [Inoteb, St. Gonnery, France], Bioglass® [US Biomaterials, Alachua, FL], Fisiograft® [Ghimas, Bologna, Italy], PepGen P-15TM [Dentsply Friadent CeraMed, Lakewood, CO], calcium sulfate, Bio-Oss® [Geistlich Pharma AG, Wohlhusen, Switzerland], and hydroxyapatite) were surrounded by bone. Some biomaterials were more resorbable than others. Included are the histomorphometry clarified features of the newly formed bone around the different grafted particles. Conclusion: All biomaterials examined resulted in being biocompatible and seemed to improve new bone formation in maxillary sinus lift. No signs of inflammation were present. The data are very encouraging because of the high number of successfully treated patients and the good quality of bone found in the retrieved specimens.

We report a case of a postextraction maxillary buccal dehiscence grafted with calcium sulfate to insert a dental implant. The clinical results were supported by histologic analysis of two specimens collected in the healed socket to better understand the biologic effects of calcium sulfate. A 42-year-old white female presented with an almost totally edentulous maxillary right arch with a wide postextraction defect in the canine region. Calcium sulfate mixed with sterile saline solution to a putty-like consistency was packed into the defect, and four dental implants were placed in the edentulous ridge. On re-entry, a dental implant and small amounts of calcium sulfate were placed in the grafted site. After 5 months, a specimen of the region implanted with calcium sulfate was retrieved for histologic evaluation. On surgical re-entry, a complete filling of the defect with mature, dense, newly formed bone occurred. Complete resorption of the grafted material and its substitution with newly formed bone tissue were confirmed by histologic analysis. All of the implants appeared to be osseointegrated successfully, and the patient was provided with a fixed implant-supported prosthesis. Calcium sulfate represents an aid in bone regeneration procedures.

The aim of this study was to assess whether there was a decrease of bacterial leakage with increasing torque values in conical Morse Cone connection implants.A total of 30 Morse Cone conical tapered implants (10 implants per group) were used in this study. The abutments were connected to the implants with 20 N (group 1), 30 N (group 2), and 40 N (group 3) insertion torque values. The inner parts of 5 implants, per group, were inoculated with Pseudomonas aeruginosa suspension and the remaining 5 implants, per group, with Aggregatibacter actinomycetemcomitans. The penetration of bacteria into the surrounding solution was determined by the observation of turbidity of the broth.In groups 1 and 2, bacterial contamination was found in 2 of the 10 implants, only in the specimens seeded with P. aeruginosa. In group 3, no contaminated samples were found.This study demonstrated that with increased insertion torque values in Morse Cone connection, the bacterial leakage is reduced.

Purpose This study was an immunohistochemical evaluation of microvessel density (MVD) in sinus augmentation procedures with autologous bone and anorganic bone (Bio-Oss). Materials and methods Twenty-four patients (14 men and 10 women - mean age of 48 years with a range from 34 to 53 years) participated in this study. All the patients presented a maxillary partial unilateral edentulism involving the premolar/molar areas, with a residual alveolar ridge height of about 4 to 5 mm. Twelve patients received sinus augmentation procedures with 100% autologous bone; 100% Bio-Oss was used in the other 12 patients. Endosseous implants were inserted after a mean period of 3 months. As control, the portions of preexisting subantral bone were used. The mean value of the MVD in control bone was 23.4 +/- 1.3. The mean value of the MVD in the sinuses augmented with autologous bone was 29.0 +/- 2.4. The mean value of the MVD in the sinuses augmented with Bio-Oss was 23.8 +/- 2.2. Results The statistical analysis showed that the differences of the MVD between control bone and sinuses augmented with Bio-Oss were not statistically significant (P = 0.52), while the difference of the MVD between sinuses augmented with autologous bone and those augmented with Bio-Oss was statistically significant (P = 0.0008). Conclusions Autologous bone may act not only as a passive filling material in bone defects but may also release osteogenic growth factors; and particles of autologous bone seem to contain vital osteoprogenitor cells.

OBJECTIVE To perform a histologic and histomorphometric analysis of the peri-implant tissue reactions and bone-titanium interface in 3 immediately loaded (provisional loaded) titanium implants retrieved from a man after a loading period of 4 months. MATERIALS & METHODS A 35-year-old patient with a maxillary partial edentulism did not want to wear a provisional removable prosthesis during the healing period. It was decided to insert 3 definitive implants and use 3 provisional implants for the transitional period. The provisional implants were loaded the same day with a resin prosthesis in occlusal contact. During the second surgical phase, after 4 months, the provisional prosthesis was removed, and the provisional implants were retrieved with a trephine bur. Before retrieval, all implants appeared to be clinically osseointegrated. The specimens were processed for observation under light microscopy. RESULTS At low magnification, it was possible to observe that bone trabeculae were present around the implant. Areas of bone remodeling and haversian systems were present near the implant surface. Under polarized-light microscopy, it was possible to observe that in the coronal aspect of the thread, the lamellar bone showed lamellae that tended to run parallel to the implant surface, while in the inferior aspect of the thread, the bone lamellae ran perpendicular to the implant surface. CONCLUSIONS Histologic data pertaining to these 3 immediately loaded implants, and retrieved after a 4-month loading period, show that immediate loading did not produce untoward effects on peri-implant bone healing.

PepGen P-15 is a combination natural anorganic bovine-derived hydroxyapatite matrix coupled with a synthetic cell-binding peptide (P-15). This material has improved bone formation in periodontal osseous defects and bone regenerative procedures. There were 3 specimens retrieved 18 months after a sinus lifting procedure using PepGen P-15. These specimens were treated to be observed under light microscopy and transmission electron microscopy. Light microscopy showed that most of the particles were surrounded by newly formed bone. In some areas, osteoid matrix was present. No acute inflammatory infiltrate was present. In transmission electron microscopy, all phases of bone formation (i.e., osteoid matrix, woven bone, and lamellar bone) were observed in the newly formed bone around the biomaterial particles. In some regions, this newly formed bone seemed to present interdigitations connecting to or entering into the particle surface. To our knowledge, this is the first report presenting data on transmission electron microscopy of PepGen P-15 used in a sinus augmentation procedure in man. Our results confirm previous reports on the clinical effectiveness of this material.