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To evaluate the influence on peri-implant soft and hard tissues of one-piece implants with a convergent hyperbolic profile collar placed at different depths with respect to the bone crest.Six dogs were included in the experiment. Three months after mandibular tooth extractions, two one-piece implants carrying a 2.8-mm-high convergent hyperbolic profile collar were placed in the alveolar crest with the coronal margin of the rough surface either 0.8 mm (test-1) or 1.8 mm (test-2) deeper with respect to the bone crest (Ct0). Two similar implants were instead placed flush to Ct0 as controls (control-1 and control-2, respectively). Healing screws were connected, and nonsubmerged healing was allowed. After 4 months, block sections were harvested, and histologic slides were prepared in a buccolingual plane.In the histologic analyses, both the buccal crest and coronal level of osseointegration were located more coronally at the test compared to the control implants concerning the implant. However, the buccal bone crest with respect to Ct0 presented a loss of 0.8 ± 0.4 mm at the test-1 and 0.5 ± 0.4 mm at the control-1 implants (P = .028), and a loss of 2.0 ± 1.0 mm and 0.7 ± 0.4 mm at the test-2 and control-2 implants (P = .028), respectively. At the control implants, the collars were exposed above the peri-implant mucosa, while those of the test implants were not. However, the coronal level of the peri-implant mucosa with respect to Ct0 was located more apically at the test compared to the control implants.The placement of implants with a hyperbolic convergent profile collar in the subcrestal position resulted in higher buccal bone resorption and more soft tissue recession compared to the crestal implants with respect to the level of the bone crest at placement.

Purpose: To monitor the early bone reaction in a canine model to a conventional sandblasted and dual acid-etched implant surface (ABT), a nanostructured hydrophilic surface (Nano), a dry salt–bioactivated ultra-hydrophilic surface (Hydro), and a bioactivated nanosurface obtained from the addition of dry salts to the Nano surface (Nano-Active). Materials and Methods: ABT, Nano, Hydro, and Nano-Active implants were placed in 12 dogs. A randomized split-mouth design was adopted. One implant of each type was placed in the mandible 3 months after tooth extraction in healed sites at the first molar region bilaterally. In the same session, the third and fourth premolars were extracted bilaterally and one implant of each type was immediately placed into the extraction socket. The dogs were euthanized at 14 and 28 days following surgery, and the peri-implant bone reaction was assessed histologically using Stevenel’s blue and alizarin red in nondecalcified sections. Results: The postoperative healing was uneventful. The 14-day histologic analysis reported nonsignificant results in terms of difference between the groups, while significant results were found 28 days after surgery. In fact, a significantly higher rate of new bone around the implant was reported in the Nano-Active compared to the Nano groups (51.0% ± 10.2% vs 36.0% ± 10.2%) and Hydro compared to the Nano groups (47.3% ± 10.7% vs 36.0% ± 10.2%). Conclusion: The results obtained indicate that new bone formed after 4 weeks demonstrated a tendency for dry salt–treated bioactivated surfaces to improve bone deposition in the interface in the early stages of healing; however, due to the limited number of dogs, the results failed to show a statistical significance. A study with a significantly larger group of animals should be performed in order to challenge the assumption that ultra-hydrophilic–surface implants might show higher bone-implant contact in immediate postextraction replacement.

Objectives The aim of the present retrospective study was to evaluate papillae filling rate and buccal margins coronal growth in implant‐supported prostheses which were over‐contoured at the apical buccal third to form a rearmost collar zone, thus mimicking a false root. Material and methods The influence of adjacent elements, teeth, implants, or pontics was examined. One‐hundred and three crowns have been assessed in photographs taken on 61 patients after prosthesis delivering and at last follow‐up (mean 2.8 years). The Jemt index was adopted to evaluate papillae growth at the baseline and follow‐up as follows: 0, absence of papilla; 1, less than half of interdental embrasure height; 2, more than half of interdental embrasure height; 3, fully papilla filled interdental embrasure. Index score 4, papilla hyperplasia was not included. Moreover, the coronal growth (or recession) of buccal mucosa in implant‐supported crowns was assessed. Results At baseline, a total of 29 papillae had a 0 score, while only two scored 3 with complete papilla formation. On follow‐up, only one papilla scored 0, while 46 scored 3 with complete interdental embrasures filling. The highest papilla score was registered from first year crown insertion and likewise in interdental embrasures located between two implants or implants and pontics. Moreover, the buccal margin growth was observed in almost 80% of crowns. Such findings seem to indicate that buccal margin and papilla around implant‐supported crowns presented a coronal growth over time, especially during its first year. The average papilla growth between two implants was no lower than that observed in papilla present between implants and natural teeth. Conclusions Recessed areas at collar of implant‐supported prostheses appear to positively influence papillae and buccal margin growth, especially in its first year. Papilla growth between two implants was similar to that observed between implants and natural teeth.

To histologically analyze the effect of a curettage of the granulation tissue on healing at implants installed immediately after the extraction of teeth presenting periapical lesions. In seven dogs, the dental pulp was removed from the pulp chamber and from the root canals of the right and left third and the fourth mandibular premolars and of the left second premolar. The chambers were left opened and, after 3 months, apical lesions were present, and the premolars were extracted. One alveolus each premolar was selected and, before implant installation, the apical lesions of two alveoli were curetted (curettage group) while the other three were not treated (no-treatment group). The second right premolar was also extracted (Negative control group). Six implants each dog were installed, and a fully submerged healing was allowed. Four months after, biopsies were collected, and histological analyses were performed. The proportions of new bone at the entire body of the implant was 70.2 ± 10.7% at the no-treatment group, 72.1 ± 14.8% at the curettage group, and 69.6 ± 3.7% at the negative control group. The respective new bone proportion at the apical aspect of the implants was 68.4 ± 17.5%, 61.5 ± 27.3%, and 78.1 ± 5.7%. None of the differences among the various groups were statistically significant. No inflammatory infiltrates were seen in the apical region. In this experimental study, it is concluded that the removal of the granulation tissue seems not to be necessary to obtain a proper osseointegration of implants installed immediately after the extraction of teeth presenting a periapical lesion.

To compare osseointegration and marginal bone level at implants placed in osteotomies prepared with either conventional drills or a piezoelectric device. Three months after the extraction of all mandibular premolars and first molars, two recipient sites were selected. The osteotomies were randomly prepared with either conventional drills (drill sites) or a piezoelectric device (piezoelectric sites). Implants were installed and a submerged healing was allowed. The animals were euthanized in groups of six after 4 and 8 weeks of healing. Biopsies were obtained for histological preparation. Coronal level of osseointegration (bone level) and bone-to-implant contact percentage (BIC%) were evaluated. After 4 weeks of healing, the bone level was 0.6 ± 0.9 mm for the piezoelectric sites and 1.6 ± 0.7 mm for the drill sites (p = 0.173). After 8 weeks, the respective measures were 0.9 ± 0.3 mm and 1.0 ± 1.1 mm (p = 0.917). After 4 weeks of healing, a new bone apposed onto the implant surface was found at fractions of 54.9 ± 6.7% and 55.1 ± 16.6% for the piezoelectric and the drill sites, respectively (p = 0.674). The respective total bone fractions, including new and old bone, was 64.0 ± 4.8% and 63.4 ± 20.4% (p = 0.917). After 8 weeks, a new bone increased to 67.4 ± 6.7% and 62.9 ± 12.5% for the piezoelectric and the drill sites, respectively (p = 0.463). The respective total bone fractions were 70.4 ± 5.5% and 67.8 ± 12.1% (p = 0.753). The use of a piezoelectric device for implant site preparation is a safe procedure that allows a proper integration since the early periods of healing similar to that observed using conventional drills.

Purpose To evaluate the osseointegration of mini-implants placed in grafted sinuses with lateral windows of two different dimensions. Materials and methods Sinus floor augmentation was performed in volunteers using a lateral window. The antrostomy was systematically prepared with a height of either 8 mm (large group) or 4 mm (small group). After 6 months of healing, mini-implants were placed in the grafted region. Biopsy specimens including the mini-implants were harvested 3 months after placement. Results Twenty biopsy specimens, 10 from each group, were suitable for the histologic analysis. Similar amounts of new bone-to-implant contact were obtained in both the large (41.1% ± 19.5%) and the small (42.8% ± 13.2%) groups (P = .940). Small percentages of residues of xenograft were found in contact with the implant surface, with 0.6% ± 1.1% in the large group and 5.9% ± 9.5% in the small group (P = .098). The new bone density around the implants was 31.7% ± 8.2% and 34.0% ± 7.9% in the large and small groups, respectively (P = .623). Conclusion The dimensions of the antrostomy did not influence the histologic healing of implants placed 6 months after sinus floor augmentation.

OBJECTIVE To study the early phases of osseointegration at implants installed in sites prepared with either high rotational speed with irrigation or low rotational speed without irrigation. MATERIAL AND METHODS After 3 months from tooth extraction, two implants were installed in one side of the mandible of twelve dogs. The osteotomies were prepared either at 60 rpm without irrigation or at 750 rpm with refrigeration. Biopsies were obtained after 4 and 8 weeks of healing, six animals each period for histological analyses. RESULTS After 4 weeks of healing, new bone percentage in contact with the implant surface (BIC%) was 46.6 ± 7.3% and 43.1 ± 6.8% at the low- and high-speed sites, respectively (p = 0.345). After 8 weeks of healing, the fractions increased to 60.0 ± 11.1% and 60.2 ± 6.2%, respectively (p = 0.753). CONCLUSIONS Implants installed in sites prepared using either low-rotational drilling without irrigation or high speed with irrigation presented similar amounts of osseointegration.

Purpose To evaluate histomorphometrically early healing at implants placed in sites prepared with either a sonic device or conventional drills. Materials and methods Sixteen volunteer patients were recruited. Two titanium mini-implants were placed in the distal segments of the maxilla in recipient sites prepared with either a sonic device or conventional drills. Biopsy specimens containing the mini-implants were retrieved after 2 weeks in eight patients, and after 6 weeks in the other eight patients. Histomorphometric analyses were performed. Results Histologic slides were available from seven patients for both 2-week and 6-week periods. After 2 weeks of healing, small amounts of new bone were found in contact with the implant surface, with 5.5% ± 7.3% and 3.8% ± 10.0% at the sonic and drill groups, respectively. After 6 weeks of healing, new bone was 46.9% ± 15.5% at the sonic group, and 46.4% ± 14.9% at the drill group. None of the differences was statistically significant. Conclusion The percentage of new bone in contact with the implant surface was similar in the sonic and drill groups.

Objective: Evaluation of the in vivo bone response of two innovative titanium surfaces ytterbium laser active fiber obtained (L1-L2) compared to a sandblasted and acid etched (SBAE) during early phase of osseointegration. Material and Methods: Three implant groups with the same macroscopic features were obtained (L1-L2-SBAE) to promote specific surface characteristics. Scanning electron microscopy, profilometric evaluation, X-ray spectrometry, and diffraction analysis were performed. For each group, six implants were placed in the tibiae of three Peli Buey sheep, and histologic, histomorphometric analysis, bone to implant contact (BIC), and the Dynamic Osseointegration index (DOI) were performed. Results: During the early phases of osseointegration, the histological and histomorphometric results showed significant differences between L1-L2-SBAE implants. At 15 and 30 days, histological analysis detected a newly bone formation around all specimens with an higher vital bone in L2 compared to L1 and SBAE both in cortical and in poor-quality marrow bone. At same time, histomorphometric analysis showed significantly higher BIC values in L2 (42.1 ± 2.6 and 82.4 ± 2.2) compared to L1 (5.2 ± 3.1 and 56.2 ± 1.3) and SBAE (23.3 ± 3.9 and 77.3 ± 0.4). DOI medium value showed a higher rate in L2 (2.83) compared to SBAE (2.60) and L1 (1.91). Conclusions: With the limitations of this pilot study, it is possible to assess that the titanium surface characteristics, and not the technologies used to obtain the modification, played a crucial role during the osseointegration process. Histological, histomorphometric, BIC, and DOI evaluation showed a significantly higher rate in L2 specimens compared to others, confirming that the implant surface could increase the bone response in cortical or marrow poor quality bone during the initial phases of osseointegration.

OBJECTIVES To evaluate the biological and mechanical complications of angulated abutments on full-arch and partial jaw rehabilitations with a follow-up for at least 1 year. METHODS Electronic search was carried out in MEDLINE, EMBASE and Web of Science. Studies published between January 2000 and January 2019 were included. The quality of the included studies was assessed. The data extraction was focused on implant loss, marginal bone loss and mechanical complications, and meta-analyses were performed for marginal bone loss, mechanical complications and implant failure. RESULTS Nine studies, three prospective and six retrospective cohort studies were included. They reported on 797 patients that received 4127 implants. The total number of abutments was 4079 of which 1673 were angulated, and 2406 were straight. All abutments were prefabricated. Angulated abutments were associated with increased implant failure rates (two studies; RR = 7.30; 95% CI = 2.79-19.08) and an effect that was both statistically significant (P

Purpose To compare the osseointegration at the portion of the implant within the elevated space after sinus elevation using different sizes of xenograft. Materials and methods Eighteen New Zealand rabbits were selected, antrostomies were prepared bilaterally through the nasal dorsum, and the sinus mucosa was elevated. Deproteinized bovine bone mineral with granules of either 1 to 2 mm (large sites) or 0.250 to 1.0 mm (small sites) were randomly used to fill the elevated space of the two sinuses. Subsequently, mini-implants were placed through the antrostomy, one in each sinus. The animals were euthanized 2, 4, and 8 weeks after surgery, six animals for each group. Microcomputed tomography (micro-CT) and histologic analyses were performed. Results In the elevated space, at the histologic analysis after 2 weeks of healing, new bone formed on the implant surface was found in fractions of 18.8% ± 6.8% and 15.8% ± 9.6% in the large and small sites, respectively (P = .249). After 4 weeks, the respective fractions of new bone were 20.3% ± 3.5% and 23.3% ± 5.6% (P = .249). After 8 weeks, the proportions reached 33.9% ± 9.5% and 28.5% ± 10.3% (P = .173), respectively. At the micro-CT analysis, bone-to-implant contact percentage (BIC%) was 21.0% ± 2.3% and 21.2% ± 2.4% in the large and small sites, respectively (P = 1.000). The respective proportions of BIC% at the large and small sites were 20.5% ± 3.3% and 23.4% ± 5.4% after 4 weeks (P = .463), and 23.0% ± 2.7% and 25.8% ± 4.1% after 8 weeks (P = .249). Conclusion The use of xenograft granules of different dimensions resulted in similar amounts of bone-to-implant contact at implants placed simultaneously with sinus floor augmentation.

To evaluate histologically the early healing at implants installed with different insertion torques MATERIAL AND METHODS: Three months after the extraction of the mandibular premolars and of the first molars, two implants were installed monolaterally in the premolar and two in the molar regions of the edentulous alveolar ridge of twelve dogs. The recipient sites were prepared using drills of different diameter to obtain insertion torque of different values, i.e., 30 Ncm (control) or ~ 70 Ncm (test) in the premolar region, and 10 Ncm (test) or ~ 50 Ncm (control) in the molar region. Six animals were euthanized after 4 weeks and six after 8 weeks of healing. Histological analyses were performed, and the Wilcoxon test was applied for statistical analyses.After 4 weeks of healing, in the premolar region, the new bone in contact with the implant surface was 65.0 ± 4.6% and 53.9 ± 13.5% at the ~ 30-Ncm and ~ 70-Ncm sites, respectively (p = 0.075). In the premolar region, new bone proportions were 51.4 ± 17.0% and 67.3 ± 7.0% at the 10-Ncm and ~ 50-Ncm sites, respectively (p = 0.046). After 8 weeks of healing, in the premolar region, new bone reached fractions of 77.7 ± 16.2% at the ~ 30-Ncm sites, and 68.3 ± 12.1% at the ~ 70-Ncm sites (p = 0.028). In the molar region, new bone presented proportions of 70.2 ± 6.4% at the 10-Ncm sites and 76.2 ± 9.4% at the ~ 50-Ncm sites (p = 0.173).The insertion torque influenced the osseointegration of implants. Higher values of bone-to-implant contact percentages were registered for insertion torques of ~ 30 Ncm and ~ 50 Ncm. Implants inserted with torque 10 Ncm became integrated with an optimal osseointegration.

To study the healing at collagenated bicortically installed implants. Twenty albino New Zealand rabbits were used for implant installation. Two implants with a double acid etched surface, coated with a collagen type I or left uncoated, were installed bicortically in the metaphysis and in the diaphysis of each tibia. Ten rabbits were euthanized after 2 weeks and ten after 6 weeks after installation. Ground sections were prepared for histological analyses that were performed both in the cortical layers and in the marrow regions. After 2 weeks of healing, highest amounts of new bone were found at the collagenated implants (43.2 ± 6.0%) compared to the standard implants (33.9 ± 6.1%; p = 0.022). After 6 weeks of healing, similar percentages of new bone were observed, being 51.8 ± 7.3% and 50.9 ± 9.6% (p = 0.678) for the standard and collagenated surfaces, respectively. A coated surface with collagen type I promoted bone apposition in the earliest periods of healing. However, the effect vanished over time so that similar results were obtained after 6 weeks of healing.

Background: Altering surface characteristics by increasing its energy and hydrophilicity will accelerate the interaction between cells and implant surface. Energy and hydrophilicity tend to disappear over a short time. The implant surface may be reactivated by the use of argon plasma Objective: To assess bone density at cleaned and activated titanium implants using argon plasma. Methods: Mandibular premolars and first molars were extracted bilaterally in eight Beagle dogs. After three months, four implants, two treated with argon plasma (test; plasma) and two left without treatment (control), were randomly installed in one side of the mandible. Abutments were applied on the implants and a non-submerged healing was allowed. After one month, the same surgical procedures were adopted on the opposite side of the mandible. The animals were euthanized after one month and ground sections representing the healing after 1 and 2 months were obtained for histological examination. Results: No statistically significant differences were found between test and control sites (p < 0.05). After 1 month of healing, new bone was 32.5 ± 12.2% and 33.8 ± 8.8% at the plasma and control sites, respectively. After 2 months, the respective values were 50.8 ± 21.5% and 47.6 ± 15.6%. Conclusion: The treatment of the implant surface with argon plasma did not have a significant effect on bone density around implants.

The aim of this study was to evaluate the reliability of 6-mm-long implants compared with normal-length implants placed in a vertical augmented atrophic posterior mandible, supporting cemented single crowns. Thirty-six patients with bilateral posterior edentulous mandible and presenting a bone availability height less than 9 mm from the mandibular canal were enrolled in this study. Patient hemiarches were randomized to receive both 6-mm-long and normal-length implants (10 mm). The technique used for the vertical bone augmentation was the “sandwich” technique, using a bone substitute block as graft. The data outcomes at 1 year postloading follow-up were the loss of implants and complications. Eighty-six 6-mm-long implants and 84 normal implants were inserted. Five short implants and 13 normal implants were lost. In 28 patients, complications occurred, and in 21 cases, the complication was present on the side of the ridge vertical augmentation. From the statistical analysis, the association between the side of the ridge augmentation and the side of occurrence of the complication was statistically significant (P < .05). The results from this trial suggest short implants can be preferred over vertical bone augmentation for the placement of longer implants in the rehabilitation of edentulous posterior mandibles. These initial results must be confirmed by larger and longer follow-ups of 5 years or more.

OBJECTIVE To histologically assess the hard and soft tissue changes after insertion of cleaned and activated titanium implants using plasma of argon. MATERIALS AND METHODS Eight dogs were included in this study. The mandibular premolars and first molars were extracted. For each hemi-mandible, four implants, 7 mm long and 3.3 mm of diameter, with a ZirTi surface were used. The surface of two implants was randomly treated with argon plasma (test), while the other two implants were left untreated (control). After 1 month, the same procedure was performed in the contralateral hemi-mandible. The amount of old bone, new bone, overall value of old bone plus new bone, and soft tissue was histologically evaluated. RESULTS After 1 month of healing, high percentages of new bone in close contact with the implant surface were found at both the treated (60.1% ± 15.6%; 95% CI 56.5%-78.0%) and untreated (57.2% ± 13.1%; 95% CI 49.3%-67.5%) implants. Low percentages of old bone were found at this stage of healing, at both the treated (4.4% ± 3.0%; 95% CI 1.2%-5.4%) and untreated (3.4% ± 3.1%; 95% CI 0.6%-4.9%) implants. Not statistically significant differences were found between groups (p > .05). After 2 months of healing, treated implants presented a significantly higher (p = .012) new bone formation (72.5% ± 12.4%; 95% CI 69.6%-86.8%) compared to untreated sites (64.7% ± 17.3%; 95% CI 59.4%-83.3%). Controversially, no difference (p = .270) in terms of old bone was present between treated (3.1% ± 1.7%, 95% CI 1.8%-4.2%) and untreated implants (3.8% ± 1.9%, 95% CI 3.2%-5.8%). Significant differences (p = .018) in terms of total mineralized bone were found between treated (75.6% ± 13.0%, 95% CI 73.3%-91.3%) and untreated implants (68.4% ± 16.8%; 95% CI 64.2%-87.6%). CONCLUSIONS Implants treated using plasma of argon was demonstrated to reach a higher bone-to-implant contact when compared to untreated implants.

Purpose To evaluate histologically and histomorphometrically the effect of a delayed load on healing at implants with a moderately rough surface. Materials and methods Two solid titanium screw-shaped devices, 5 mm long and 3.5 mm in diameter, were inserted in the distal segments of the alveolar ridge of 16 volunteer patients in a nonsubmerged fashion. After 2 months, one implant was loaded, while the other was left unloaded. After 2 months, the two implants were collected from 10 patients using a sonic instrument, and ground sections were prepared from the biopsy specimens. Histomorphometric analyses were performed. Results After 4 months of healing, biopsy specimens from 10 patients were available for analyses (n = 10). The total bone-to-implant contact percentage was 86.8% ± 6.5% and 84.6% ± 3.7% for loaded and unloaded implants, respectively. New bone was represented by 85.5% ± 6.7% and 83.4% ± 3.9% at the loaded and unloaded sites, respectively. A very small amount of old parent bone was found. The density of the mineralized bone was 76.8% ± 8.3% for the loaded sites and 74.1% ± 10.5% for the unloaded sites. The percentages of new and old bone densities were 69.0% ± 8.3% and 7.8% ± 3.9% at the loaded sites, and 65.9% ± 10.3% and 8.2% ± 4.5% at the unloaded sites, respectively. No statistically significant differences were disclosed. Conclusion Applying a delayed load to implants supporting single crowns did not yield statistically significant differences, and only a tendency of higher osseointegration and bone density was observed at loaded sites compared with the unloaded sites.

The aim of this study was to analyze the degree of mineralization around nine clinically stable titanium dental implants retrieved after 2 months to 17 years for mechanical complications from five patients. The micromorphology and microchemistry of the interface bone at the coronal and apical sides of the threads were analyzed by environmental scanning electron microscope and energy-dispersive X-ray spectroscopy (EDX) on histologic samples. Mineralization was investigated by atomic calcium-to-nitrogen (Ca/N), phosphorous-to-nitrogen (P/N), and calcium-to-phosphorous (Ca/P) ratio evaluation (statistical analysis by two-way analysis of variance with Student-Newman-Keuls; P < .05). EDX showed higher Ca/N, P/N, and Ca/P values for the bone at the coronal side compared to the apical side of the threads in the long-term (≥ 14 years) samples. The two most significant findings were that (1) the interface bone located at the coronal side of the implant threads was generally more mineralized than the interface bone located at the apical side, and (2) the mineralization of the peri-implant bone at the interface increased over time. A higher degree of mineralization was found at 2 months in an immediately loaded implant when compared to the 2-month submerged unloaded control, likely related to the different remodeling events (coronal vs apical side of the implant threads) due to the direction of the loading forces.

The aim of the present study was to evaluate the effect of the induction of peri-implantitis and of plaque accumulation on implants with different surface characteristics after the surgical treatment. All mandibular premolars and first molars were extracted bilaterally in six dogs. After 3 months, two non-submerged implants were installed, each with either a hydrophilic sandblasted and acid-etched surface stored in saline solution (SLActive) or an acid-etched and modified with calcium ions surface (UnicCa). After 3 months, ligatures were placed in the sulcus around the implants to induce an experimental peri-implantitis and plaque accumulation was allowed. After 3 months, ligatures were removed and, after one more month of plaque accumulation, a surgical treatment was performed using gauzes soaked in saline and irrigations. X-rays were taken at this stage. Plaque control maintenance was established at the control sites, while plaque accumulation was allowed at the test sites (plaque sites). After 5 months, biopsies were obtained. Marginal bone levels were compared between x-rays and histological assessments. At the time of peri-implantitis treatment, two SLActive implants were lost. At the euthanasia, seven more implants were lost only in the plaque group, one control and six test implants. The calculated mean values of the marginal bone level of the two surfaces at the treatment were 3.65 ± 1.71 mm in the control group, and 3.65 ± 1.76 mm in the plaque group (p = 0.463). The additional marginal bone loss after 5 months from surgical treatment was 0.67 ± 0.67 mm (UnicCa, 0.48 ± 1.06 mm and SLActive, 0.79 ± 2.10 mm) and 3.11 ± 1.38 mm (UnicCa, 2.67 ± 1.87 mm and SLActive, 3.94 ± 2.11 mm) for the control and plaque groups, respectively (p = 0.028). The lack of plaque control after the surgical treatment of the peri-implantitis strongly influenced the marginal bone loss.

Objectives To evaluate histomorphometrically the healing at implants installed with standard or very low insertion torque values Material and methods Twelve volunteer patients were recruited, and two screw-shaped titanium devices were installed in the distal segments of the mandible using insertion torque values of either < 10 Ncm or ~ 30 Ncm. The implants were left to heal in a non-submerged fashion. After 8 weeks, biopsies were retrieved, and ground sections were prepared for histological evaluation. Results Histological slides from 11 patients were available for (n = 11). The new bone in contact with the implant surface was 39.3 ± 18.5% and 49.4 ± 9.4% at the < 10 and ~ 30 Ncm sites, respectively. Considering the pre-existing old bone, the total mineralized bone was 46.8 ± 22.1% at the < 10 Ncm sites and 57.0 ± 14.1% at the ~ 30 Ncm. No statistically significant differences were found. New bone density and total mineralized bone density were 36.6 ± 8.1% and 53.0 ± 13.5% at the < 10 Ncm sites and 35.9 ± 10.0% and 52.2 ± 16.0% at the ~ 30 Ncm sites, respectively. No statistically significant differences were disclosed. Conclusion From the data of the present study, it can be concluded that a trend of higher osseointegration was observed at the ~ 30 Ncm compared to the < 10 Ncm torque group. Nevertheless, it can be concluded that an implant installed with a very low torque may achieve a good integration. Trial registration ClinicalTrials.gov NCT04017156; trial retrospectively registered on 12 July 2019.

Objectives The purpose of this prospective, single-center randomized pilot study was to histologically evaluate and compare vital bone development in premolar and molar-extraction sites grafted with two different bovine-derived xenografts. The secondary outcome of interest was implant survival in the grafted sites. Materials and methods Adult patients in need of at least two tooth extractions were enrolled. A paired design was used; each patient received at least one of each type of graft at different sites. Each extraction site was randomized to one of two xenograft treatment groups. A resorbable membrane was always placed, and primary intention soft tissue closure was achieved. Four months later, implants were placed and a trephine drill was used to remove bone cores for histologic and histomorphometric analysis. Results Sixteen patients with 40 extraction sites were enrolled; 20 sites were grafted with one type of xenograft and 20 with another. Mean patient age was 53.5 years, and 65% of patients were male. Evaluation of bone core samples taken from grafted sites showed no significant difference in the mean value of percentage of new bone formation between the different grafted sites (33.4% and 32.4%, p = .76). Cumulative implant survival was 97.5% at the 24-month follow-up visit. Conclusion Within the limitations of this pilot study, no statistically significant differences in new bone growth between sites grafted with two different types of xenograft were found. Both graft materials promoted the formation of new bone and provided osseous support for implant placement after socket grafting.

Background Various anatomical references and structures should be analyzed prior approaching a surgery in the maxillary sinus. The objective of the present study was to evaluate the anatomical structures and references involved in sinus floor elevation with a lateral approach. Materials and methods Seventy-five patients planned for sinus floor elevation were included in the study. Eighty-eight maxillary sinuses were evaluated using cone beam computed tomographies (CBCTs). The nasal floor was used as main reference (X) and sinus mucosa width, bone crest height, palatal–nasal recess angle (PNR), sinus width at the level of the nasal floor, distance from the nasal floor to the base of the sinus (X–F), position of the posterior superior alveolar artery (PSAA height) and diameter (PSAA diameter), lateral bone wall width at 3 mm (LW 3 mm) and 9 mm (LW 9 mm) from the base of the sinus (F), patency of the ostium (OP), and presence and position of septa have been evaluated. Results The mean dimensions and standard deviations were the following: mucosa thickness was 2.0 ± 1.4 mm, bone crest height 2.8 ± 1.4 mm, distance X–F 8.3 ± 1.9 mm, PNR angle 135.5 ± 23.1, sinus width 12.6 ± 4.2 mm, X–F 8.3 ± 1.9 mm, PSAA height 14.4 ± 2.9 mm, PSAA diameter 1.1 ± 0.4 mm, LW 3 mm 1.5 ± 1.2, LW 9 mm 1.3 ± 0.6 mm, OP 1.9 ± 0.4 mm. Septa were present in 19.3% of the sinuses evaluated and were located mostly in the molar region. Conclusions In conclusion, the analysis of the CBCT before sinus floor elevation allows the identification of anatomical structures and references that might be used for the planning of the surgical approach, aiming to improve the outcome of the treatment and to avoid possible complications.

AIM: To evaluate the clinical and radiographic outcomes and the survival rates of fiber-reinforced composite resin-bonded fixed prostheses (FRCRBFDPs) placed in the posterior area supported by two short (6 mm) implants. MATERIALS AND METHODS: Twenty consecutive patients received 40 SLActive 6-mm-long implants with a diameter of 4.1 mm (n = 29) or 4.8 mm (n = 11). Insertion torques and RFA (Resonance Frequency Analysis) were measured at implant installation. The prosthetic rehabilitation was performed after 8 weeks from insertion with a screw-retained two- or three-unit fixed dental prosthesis fabricated of FRCRBFDPs. Implant survival rates and marginal bone levels were evaluated at various time intervals until 5 years after loading. RESULTS: Two of 20 patients lost four implants supporting two FRCRBFDPs between the second and the third year of follow-up (cumulative survival rate: 90% after 5 years). Four patients suffered a fracture of the prosthetic reconstruction, and the success rate of the rehabilitation was 70% after 5 years. A mean marginal bone loss of 0.30 ± 0.34 mm was found after 5 years of function at the remaining implants. CONCLUSION: The survival of short implants was 90% owing to two bridges losses in the maxilla. However, the success rate of FRCRBFDPs over 5 years was only at 70%.

OBJECTIVE To evaluate in vitro the quality of dental implant biopsies collected using trephines or a sonic instrument. METHOD Sixty implants, 4 mm long and 2.4 mm in diameter, were installed in twelve fresh bovine ribs. Biopsies were collected after using three different methods for retrieval, 20 biopsies representing each group: (A) A trephine used concentrically; (B) a trephine used eccentrically; and (C) a sonic device (Sonosurgery(®) ). The time used for biopsy collection was recorded, and an evaluation of the quality of the biopsies obtained was performed. The specimens were subsequently prepared for ground sections, and tissue-to-implant contact percentages (TIC%) were evaluated in a stereomicroscope. RESULTS Time needed for biopsy collection in Groups A and B was between 2 and 3 min, while in C, it amounted to 10-11 min. The differences between Group C and the other two groups were statistically significant (P < 0.00006). Group C showed significantly greater volumes of tissue around the apex of the implants compared with the other two groups (P < 0.027). Groups A and C showed biopsies with higher quality compared with Group B (P < 0.05). Group C presented a higher TIC% compared with the other two groups (P < 0.008). CONCLUSION Compared with the use of trephines, the use of a sonic device for harvesting biopsies resulted in higher-quality biopsies and generated smaller residual defects. However, the harvesting was more time-consuming and was limited to one aspect of the implants.

The aim of this in vitro study was to evaluate the early cell response and protein adsorption elicited by the argon plasma treatment of different commercially available titanium surfaces via a chair-side device. Sterile disks made of grade 4 titanium ( n = 450, 4-mm diameter) with 3 surface topographies (machined, plasma sprayed, and zirconia blasted and acid etched) were allocated to receive 4 testing treatments (2% and 10% protein adsorption and cell adhesion with MC3T3-E1 and MG-63). Furthermore, the specimens were divided to undergo 1) argon plasma treatment (10 W, 1 bar for 12 min) in a plasma reactor, 2) ultraviolet (UV) light treatment for 2 h (positive control group), or 3) no treatment (control group). Pretreatment surface analyses based on a scanning electron microscope and profilometer images were also performed. Profilometric analysis demonstrated that the evaluated specimens perfectly suit the standard parameters. The use of argon plasma was capable of affecting the quantity of proteins adsorbed on the different surfaces, notwithstanding their roughness or topographic features at a low fetal bovine serum concentration (2%). UV light treatment for 2 h attained similar results. Moreover, both the plasma of argon and the UV light demonstrated a significant increase in the number of osteoblasts adherent at 10 min in all tested surfaces. Within its limitations, this in vitro study highlights the potential biological benefits of treating implant surfaces with plasma of argon or UV, irrespective of the roughness of the titanium surface. However, in vivo experiments are needed to confirm these preliminary data and settle the rationale of a treatment that might be clinically relevant in case of bone-reparative deficiencies.