The Effects of Abutment Materials on Peri-Implant Soft Tissue Integration: A Study in Minipigs.

PURPOSE: To evaluate, in a minipig model, the soft tissue integration of four different transmucosal materials, as well as the peri-implant bone remodeling. MATERIALS AND METHODS: A total of 40 implants were placed in five minipigs in a single stage surgery, and two of each of the following abutment materials were used in each animal: (1) titanium (Ti; control), (2) polymethylmethacrylate (PMMA), (3) zirconia (Zi), and (4) veneering ceramic (VC). After a healing period of 3 months, the samples were collected and subjected to nondecalcified histology. The soft tissue dimensions (sulcus, junctional epithelium, and connective tissue attachment) were assessed on each abutment and the distance from the implant margin to first bone-to-implant contact (BIC) was measured. RESULTS: The mean biological width-characterized by the sum of junctional epithelium and connective tissue measurements-was 3.8 (0.6) mm and no statistically significant difference was found between the four groups (p = 0.41). However, a long junctional epithelium (3.3-3.8 mm) and a very short connective tissue attachment (0.1-0.2 mm) were observed with all abutments. The measured peri-implant bone remodeling was similar in all four groups (p = 0.88). CONCLUSIONS: Within its limitations, this study showed that all tested materials allowed soft tissue integration, consisting of a long junctional epithelium, extending close to the bone level, and a rather short portion of connective tissue.

Intraoperative and postoperative outcomes of sinus floor elevation using the lateral window technique versus the hydrodynamic transalveolar approach: a preliminary randomized controlled trial.

OBJECTIVES: To compare the clinical and radiographic outcomes of two sinus floor elevation techniques: the conventional lateral window technique versus the transalveolar approach using a hydrodynamic ultrasonic device. MATERIALS AND METHODS: The study was designed as a randomized controlled clinical trial, and participants were randomly allocated to the control group (lateral window: LW) or to the test group (hydrodynamic transalveolar approach: HTA). The intraoperative and postoperative data, including procedure duration and patient-reported outcome measures (PROMs), were collected during the surgery and up to 1 year post-surgery. Additionally, qualitative assessment of gained bone volumes and implant survival rates was recorded. RESULTS: Twenty-two patients were included in the study. The mean surgical time was significantly longer in the HTA compared to the LW group (48.1 ± 11.2 min vs. 35.2 ± 9.1 min, P = 0.0011). Perforation of the Schneiderian membrane occurred in 2/11 and 5/11 patients in the LW and the HTA group, respectively (P = 0.36). Postoperatively, higher morbidity and consumption of nonsteroidal anti-inflammatory drugs (NSAIDs) were associated with the LW group. However, self-reported satisfaction with surgical procedures was similar in the two groups. At 1 year, implant survival rates of 80% in the HTA group and 100% in the LW group were recorded (P = 0.12). CONCLUSIONS: Although the new transalveolar approach seems to reduce postoperative morbidity, an increased risk of intraoperative complications compared to the LW approach needs to be considered when choosing a technique. CLINICAL RELEVANCE: Our results provide new insights regarding clinical and radiographic outcomes of HTA and may help further determine indications for its use. TRIAL REGISTRATION: ClinicalTrivals.gov : NCT04499625.

Maxillary implant overdenture retained by four unsplinted attachments and opposed by a natural or fixed dentition: One-year clinical outcomes.

OBJECTIVES: The aim of this prospective study was to evaluate the implant, prosthesis, and patient-reported outcomes of maxillary removable prostheses retained by 4 implant-supported study abutments after a follow-up period of 1 year in patients with natural teeth or a fixed rehabilitation in the mandible. MATERIALS AND METHODS: A total of 30 patients were included, and all received 4 implants in the upper maxilla. After 12 weeks, the prostheses were connected to the implant with unsplinted attachments. The implant and prosthodontics outcomes were assessed over a follow-up period of 1 year. Patient-reported outcome measures (PROMs) were evaluated with the Oral Health Impact Profile (OHIP-20) questionnaire and an adaptation of the McGill Denture Satisfaction Instrument using a visual analogue scale (VAS). RESULTS: A single patient dropped out. At the post-operative 12-week follow-up, 79.3% (95% CI: 64.6%-94.1%) of the patients displayed peri-implant mucosa hyperplasia and 69.0% (95% CI: 52.1%-85.8%) showed pain. After 1 year, 16 implants failed in 10 patients, leading to an implant survival rate of 86.2% (95% CI: 79.0%-92.5%), and the mean peri-implant bone loss was 1.01 ± 0.77 mm (95% CI: 0.85-1.16 mm). The prosthesis survival rate was 96.6% (95% CI: 82.2%-99.9%). The OHIP-20 and VAS scores both improved significantly from baseline to 1 year (p < .001). CONCLUSION: The implant survival rate was lower compared to the literature for the upper maxilla. Despite the encountered problems, PROMs showed significant improvement with the implant overdenture retained by 4 unsplinted implants compared to conventional dentures.

Clinical and radiographic assessment of circular versus triangular cross-section neck Implants in the posterior maxilla: A 1-year randomized controlled trial.

OBJECTIVES: Implants with a triangular neck were recently introduced to limit peri-implant bone loss. The primary objective of this randomized controlled trial was to compare peri-implant bone changes of circular versus triangular cross-section neck implants 1 year after loading. The secondary objectives were to assess buccal hard tissue thickness changes, Pink Esthetic Score (PES), and patient satisfaction. MATERIAL AND METHODS: Thirty four patients requiring replacement of the single, intercalated missing tooth of healed site for at least 4 months in the posterior maxilla were randomized into 2 groups according to the type of implant. Immediately after surgery and 1 year after final restoration, a cone beam CT (CBCT) was performed to assess proximal bone remodeling and buccal bone thickness. Peri-implant soft tissue health, PES, and patient-reported outcome measures (PROMs) were recorded. RESULTS: No implant loss occurred within the follow-up period. The mean ± SD peri-implant proximal bone loss 1 year after loading was 0.22 ± 0.30 mm for triangular and 0.42 ± 0.67 mm for circular implants necks (p = .25). Peri-implant bone loss exceeding 2 mm was observed in a single implant in the circular neck group. Buccal bone thickness remained stable and did not differ different between the 2 groups. The peri-implant soft tissue health, PES, and patient satisfaction were also comparable. CONCLUSIONS: Within the limitations of the present study, patient clinical and radiographic outcomes did not differ between triangular and circular cross-section neck implants in the posterior maxilla.

Effectiveness of temporary implants in teenage patients: a prospective clinical trial.

AIMS: The objective of this study was to assess prospectively the outcomes of extra-narrow diameter implants (XNDI) placed in teenage patients as a temporary restorative option. MATERIAL AND METHODS: Twenty consecutive young patients presenting one or several missing teeth received XNDI that were immediately restored with composite, Polymethylmethacrylate (Acrylic) or ceramic crown. Clinical and radiographical outcomes were assessed for a minimum follow-up period of 1 year. Additionally, each patient completed retrospectively a satisfaction questionnaire using Visual Analog Scale (VAS). RESULTS: A total of 30 implants were placed and followed for a period of 1-7.4 years (mean: 3.59 years). One implant failed after 3 weeks and was replaced successfully. No further biological complications occurred during the follow-up period, leading to an implant survival rate of 96.6%. The patient satisfaction evaluations displayed high levels of comfort and function. CONCLUSION: Immediately restored XNDI to replace missing teeth on teenager patients seems to be an effective temporary restorative option to replace missing teeth in young patients. Composite or ceramic crowns should be preferred. Clinical trials with long-term follow-ups and the assessment of passive egression are needed.

Impact of biomaterial microtopography on bone regeneration: comparison of three hydroxyapatites.

AIMS: The primary objective of this study was to compare the in vivo performance, namely in terms of quantity of newly formed bone and bone-to-material contact (osteoconductivity), of three hydroxyapatite-based biomaterials (HA) of different origins (natural or synthetic) or manufacturing process in a sinus lift model in rabbits. The secondary objective was to correlate the findings with the physical and topographical characteristics of the biomaterials. MATERIALS AND METHODS: Two bovine HA manufactured with different processes (bovine hydroxyapatites [BHA] and cuttlebone hydroxyapatite [CBHA]) and a synthetic hydroxyapatite (SHA) sintered at high temperature were characterised with scanning electronic microscopy (SEM) and the measurement of specific surface area (BET). The materials were implanted in a sinus lift model in rabbits; histological and histomorphometric evaluation using non-decalcified sections was performed at 1, 5 and 12 weeks after implantation. RESULTS: The studied biomaterials displayed a different surface topography. The two natural HA displayed significantly higher bone quantities (P = 0.0017; BHA vs. SHA, P = 0.0018 and CBHA vs. SHA, P = 0.033) at 5 and 12 weeks compared to the synthetic one (SHA). Moreover, the osteoconductivity (bone-to-material contact) was significantly higher in the BHA group compared to the two other groups (P = 0.014; BHA vs. SHA, P = 0.023 and BHA vs. CBHA, P = 0.033). CONCLUSION: HA-based biomaterials from diverse origins and manufacturing processes displayed different topographical characteristics. This may have influenced different regenerated bone architecture observed; more bone was found with natural HA compared to the synthetic one, and significantly higher bone-to-material contacts were found with BHA.

Occurrence and risk indicators of medication-related osteonecrosis of the jaw after dental extraction: a systematic review and meta-analysis.

AIMS: The primary objective was to assess the occurrence rate of Medication-Related OsteoNecrosis of the Jaw (MRONJ) after dental extraction in patients treated with Antiresorptive Drugs (ARD) for OsteoPorosis (OP) or for oncological reasons. The secondary objective was to compare the extraction techniques regarding the occurrence of MRONJ. MATERIALS AND METHODS: A systematic search in PubMed/MEDLINE, EMBASE and LILACS databases was performed. Prospective studies considering human patients treated with ARD and providing information regarding the occurrence of MRONJ after dental extraction were selected. Meta-analysis for incidence of MRONJ at the patient level was performed. The effect of administration route and surgical technique on MRONJ was evaluated. RESULTS: The risk of MRONJ after dental extraction was significantly higher in patients treated with ARD for oncological reasons (3.2%) than in those treated with per os ARD for OP (0.15%) (p < 0.0001). Dental extraction performed with adjusted extraction protocols decreased significantly MRONJ development. Potential risk indicators such as concomitant medications and pre-existing osteomyelitis were identified. CONCLUSION: The risk of MRONJ after dental extraction in patients treated with ARD exists, especially in patients treated for oncologic reasons. This risk tends to decrease with adjusted extraction protocols.

Dramatic osteonecrosis of the jaw associated with oral bisphosphonates, periodontitis, and dental implant removal.

INTRODUCTION: Osteoporosis affects millions of elderly patients, and anti-resorptive drugs (ARD) such as bisphosphonates (BP) represent the first-line therapy. Despite the benefits related to the use of these medications, osteonecrosis of the jaw is a significant complication in a subset of patients receiving these drugs. CASE PRESENTATION: This report documents a case of dramatic bisphosphonate-related osteonecrosis associated with periodontitis and dental implant removal in an osteoporotic patient treated with per os bisphosphonates for an uninterrupted period of 15 years. CONCLUSION: The aim of this report was to discuss the administration period of BP in the treatment of osteoporosis, the decision-making and clinical management of severe MRONJ and the indications for dental implant placement in these specific patients.

Long-term stability of peri-implant tissues after bone or soft tissue augmentation. Effect of zirconia or titanium abutments on peri-implant soft tissues. Summary and consensus statements. The 4th EAO Consensus Conference 2015.

INTRODUCTION: Several surgical techniques and prosthetic devices have been developed in the last decades, aiming to improve aesthetic, hygienic and functional outcomes that may affect the peri-implant tissues, such as procedures of bone and soft tissue augmentation and the use of custom-made abutments of titanium and zirconium. MATERIALS AND METHODS: Three systematic reviews, based on randomized clinical trials and prospective studies covering the above reported topics were analysed, and the detected evidence was exposed to interactive experts' discussion during the group's and general assembly's meetings of the 4th EAO Consensus Conference. The results are reported using the following abbreviations: S-T: short-term evidence, M-T: medium-term evidence; L-T: long-term evidence; LE: limited evidence. RESULTS: Soft tissue augmentation procedures may be indicated for the increase of soft tissue thickness and keratinized tissue, the reduction of interproximal peri-implant bone loss, and the coverage of shallow peri-implant soft tissue recessions (S-T, LE), L-T is lacking. Guided bone regeneration approaches (GBR) showed efficacy when used for ridge reconstruction after the complete healing of the soft tissues (S-T & L-T), and the stability of the augmented bone may play a role in the maintenance of the soft tissue position and dimensions (LE). No significant differences were observed between titanium and zirconia abutments when evaluating probing pocket depth, bleeding on probing, marginal bone levels and mucosal recessions. Zirconia abutments were associated with more biological complications but demonstrated superiority in terms of achieving natural soft tissue colour (S-T).

Coronally advanced flap versus the pouch technique combined with a connective tissue graft to treat Miller's class I gingival recession: a randomized controlled trial.

AIM: The objective of this study was to compare two different periodontal plastic surgery procedures to treat Miller's class I recession: a coronally advanced flap(control group) versus the pouch technique (test group), both of which were associated with connective tissue graft. METHODS: Forty consecutive patients were included, with 20 patients being allocated for each group. The level of recession coverage, the keratinized tissue (KT)quantity, gingival aesthetics (PES) and post-operative outcomes were assessed for a follow-up period of 6 months. RESULTS: After 6 months, both techniques allowed for the excellent mean root coverage of 96.3 plus/minus 12.1% in the control group and of 91.3 plus/minus 17.6% in the test group.Complete root coverage was achieved in 89.5% (17/19) and 79% (15/19) of the recession cases in the control and the test groups respectively. A significant increase in KT height (p = 0.0011) was observed in the test group. A significant improvement in the pink aesthetic score was found in the two groups, but gingival texture displayed significantly better results in the test group (p < 0.0001). No significant difference between the two groups was found in terms of the morbidity outcomes. Pain killer consumption was similar in the two groups and significantly decreased over time. CONCLUSIONS: Both surgical techniques are relevant in treating Miller's class I recession. The pouch technique seems to increase the height of KT better and provides good gingival-related aesthetic outcomes.

A methodological approach to assessing alveolar ridge preservation procedures in humans: soft tissue profile.

INTRODUCTION: The aesthetic results of implant restoration in the anterior maxilla are particularly related to the soft tissue profile. Although socket preservation techniques appear to reduce bone remodelling after tooth extraction, there is still few investigations assessing the external soft tissue profile after such procedures. The goal of this study was to describe an accurate technique to evaluate soft tissue contour changes after performing socket preservation procedures. The secondary objective was to apply the newly developed measuring method to a specific socket preservation using a "saddled" connective tissue graft combined with the insertion of slowly resorbable biomaterials into the socket. MATERIALS AND METHODS: A total of 14 patients needing tooth replacement in the aesthetic region were included to receive a socket preservation procedure using a connective tissue graft. Impressions were taken before the tooth extraction (baseline) and at 2, 4, and 12 weeks after the procedure. The corresponding plaster casts were scanned, and the evolution of the soft tissue profile in relation to the baseline situation was assessed using imaging software. RESULTS: The measuring technique allowed assessing the soft tissue profiles accurately at different levels of the alveolar process. The insertion of a saddled connective tissue appeared to compensate for the horizontal and vertical bone remodelling after a socket preservation procedure in most regions of the alveolar crest. After 12 weeks, the only significant change was located in the more cervical and central region of the alveolar process and reached a median drop of 0.62 mm from baseline. CONCLUSION: Within the limitations of this study, we found that a saddled connective tissue graft combined with a socket preservation procedure could almost completely counteract the bone remodelling in terms of the external soft tissue profile. The minor changes found in the cervical region might disappear with the emergence profile of the prosthodontic components. The described technique might therefore enhance the aesthetic outcomes when a tooth has to be replaced in the aesthetic zone. The described protocol can be used to further compare the effectiveness of different extraction socket preservation protocols in randomised controlled trials.

Biological performance of a novel bovine hydroxyapatite in a guided bone regeneration model: A preclinical study in a mandibular defect in dogs.

OBJECTIVES: This preclinical model study aims to evaluate the performance and safety of a novel hydroxyapatite biomaterial (Wishbone Hydroxyapatite, WHA) on guided bone regeneration compared to a commercially available deproteinized bovine bone mineral (Bio-Oss, BO). MATERIAL AND METHODS: Twenty-four beagle dogs were allocated to three timepoint cohorts (4, 12, and 26 weeks) of eight animals each. In all animals, four critical-sized, independent wall mandibular defects were created (32 defects/cohort). Each animal received all four treatments, allocated randomly to separated defects: WHA + collagen membrane (M), BO + M, no treatment (Sham, Sh), and Sh + M. At each timepoint, the specimens were harvested for histologic and histomorphometric analyses to determine the newly formed bone and osteoconductivity. RESULTS: At 4 weeks, bone regeneration was significantly higher for WHA + M (46.8%) when compared to BO + M (21.4%), Sh (15.1%), and Sh + M (23.1%) (p < 0.05); at 12 and 26 weeks, regeneration was similar for WHA and BO. Bone-to-material contact increased over time similarly for WHA + M and BO + M. From a safety point of view, inflammation attributed to WHA + M or BO + M was minimal; necrosis or fatty infiltrate was absent. CONCLUSIONS: WHA + M resulted in higher bone regeneration rate than BO + M at 4 weeks. Both BO + M and WHA + M were more efficient than both Sh groups at all timepoints. Safety and biocompatibility of WHA was favorable and comparable to that of BO.

The effect of collagenated space filling materials in sinus bone augmentation: a study in rabbits.

AIM: The inclusion of biomaterial particles used for alveolar bone regeneration in a carrier or in binding agents such as collagen gel or fibers is of interest as a means to help with surgical handling. However, the possible influence of collagen on bone tissue response to biomaterials is poorly studied. The objective of the present study was to investigate, in a sub-sinus bone augmentation model in rabbits, the effect of collagen at different stages of the osteogenesis process. Histologic, histomorphometric and volumetric analyses were performed. MATERIALS AND METHODS: Rabbits underwent a double sinus lift procedure using bovine hydroxyapatite (BHA), collagenated bovine hydroxyapatite (BHAColl), and prehydrated and collagenated porcine hydroxyapatite (PHAColl). Animals were sacrificed at 1 week, 5 weeks or 6 months. Samples were subjected to X-ray micro-tomography and histology. Qualitative analysis was performed on the non-decalcified sections and quantitative histomorphometric analyses were conducted using scanning electron microscopy (SEM). Volume variations of bone augmentations were calculated at different time points. RESULTS: The three biomaterials allowed an optimal bone formation and were able to equally withstand sinusal reexpansion. A comparable percentage of new bone, as well as 3D volume stability, was found between the groups at each time point. However, the PHAColl resorption rate was significantly higher than the rates in other groups (P = 0.0003), with only 3.6% of the particles remaining at 6 months. At 1 week, both collagenated groups displayed the presence of inflammatory cells although BHA did not show any sign of inflammation. At 5 weeks and 6 months, the inflammatory process had disappeared completely in the BHAColl groups, whereas some inflammatory-like cells could still be observed around the remaining particles of PHAColl. CONCLUSIONS AND CLINICAL IMPLICATIONS: Within the limitations of this study in rabbits, the findings showed the presence of inflammatory-like cells at the early stage of bone regeneration when collagenated xenogenic biomaterials were used compared to xenogenic granules alone. Nevertheless, similar bone formation occurred and comparable 3D volumes were found at 6 months in the different groups.

The Effects of Direct Polymethyl Methacrylate and Zirconia-on-Ti-Base Abutments on Peri-implant Soft Tissue Integration: A Study in Minipigs.

PURPOSE: To assess two types of abutment materials routinely used in daily practice-direct polymethyl methacrylate (PMMA) and a zirconia-on-Ti-base abutment-and their effects on peri-implant soft tissues and bone remodeling in a minipig model. MATERIALS AND METHODS: A total of 40 implants were placed in five minipigs in a single-stage surgery. Four different types of abutment materials (n = 10 per group) were used: (1) titanium (control); (2) zirconia (control); (3) PMMA (test 1); and (4) Ti-base (zirconia bonded to a titanium framework; test 2). After 3 months of healing, the samples were collected and subjected to nondecalcified histology. The soft tissue dimensions (sulcus, junctional epithelium, and connective tissue attachment) were assessed on each abutment mesially and distally, and the distance from the implant margin to the first bone-to-implant contact (BIC) was measured. RESULTS: No statistically significant differences were found among the four groups regarding soft tissue dimensions (P = .21), and a long junctional epithelium (mean: 4.1 mm) and a short connective tissue attachment (mean: 0.3 mm) were found in the majority of abutments. In some samples, the junctional epithelium extended all the way to the bone level. The measured peri-implant bone remodeling was similar in all four groups (P = .25). CONCLUSIONS: The present findings indicate that both direct PMMA and zirconia-on-Ti-base abutments seem to allow soft tissue integration similar to that of titanium and zirconia abutments. However, clinical studies are warranted to either confirm or refute the observed findings and to further investigate the influence of different materials on mucointegration.

A methodological approach to assessing alveolar ridge preservation procedures in humans: hard tissue profile.

AIMS: Multiple surgical protocols using biomaterials have been proposed to limit the typical post-extraction bone resorption. However, because of the heterogeneity of the studies, particularly the differences in assessment methods, it is difficult to determine the superiority of one technique over another. The objective of this study was to describe a new radiographic method to draw a map of alveolar bone remodelling after alveolar ridge preservation procedures to compare different surgical techniques more accurately. The newly developed measuring method was applied to a case series describing a specific preservation technique. MATERIALS AND METHODS: Fourteen extraction sites (in 14 patients) located in the upper anterior maxilla were treated with bovine hydroxyapatite (0.25- to 1-mm particles) and a saddled connective tissue graft. A radiographic three-dimensional assessment of the hard tissues was performed at baseline and 3 months after the procedure. Standardized horizontal measurements were taken at three corono-apical levels (-2, -5 and -9 mm) and at three mesio-distal levels (mesial, centre and distal) in the buccal and palatal aspects. Vertical measurements were also recorded in nine regions superior to the alveolar crest. The measurements were performed by two independent observers and intra- and inter-observer effects were evaluated. RESULTS: No inter- and intra-observer effects were found when analysing the measurements from these two observers. The horizontal dimension of the crest decreased by 1.6 mm (20%) in the cervical regions (-2 mm level), decreased moderately, by 1 mm (12%), at the -5 mm level and decreased very little, 0.5 mm (6%), at the apical (-8 mm) level. The losses were always significantly higher in the buccal than in the palatal aspect. Buccally, the maximal bone remodelling at the cervical level remained below 1 mm. Vertical bone resorption was homogeneous and<1 mm in the nine measured regions. DISCUSSION: The radiographic measuring methodology proved to be reproducible. It can be applied in other clinical settings. It successfully assessed the alveolar ridge preservation technique (BHA+saddle connective tissue graft).

Influence of space-filling materials in subantral bone augmentation: blood clot vs. autogenous bone chips vs. bovine hydroxyapatite.

AIM: The first objective of the present study was to compare the short- and long-term 3D volume stability of sub-sinusal bone regeneration in rabbits using different space fillers. The second objective was to assess qualitatively and quantitatively the early bone formation process and long-term behavior of the regenerated bone. MATERIALS AND METHODS: Fifteen rabbits underwent a double sinus lift procedure using: blood clot (Clot), autogenous bone chips (Auto) and bovine hydroxyapatite (BHA). Animals were euthanized at 1 week, 5 weeks and 6 months. Samples were subjected to X-ray microtomography and histology. Variations in the volume of bone augmentations were calculated at different time points. Qualitative analysis was performed using 7 µm sections and quantitative histomorphometric analyses were carried out using scanning electron microscopy. RESULTS: From baseline (100%) to 5 weeks, the augmented volumes declined to 17.3% (Clot), 57.6% (Auto) and 90.6% (BHA). After 6 months, only 19.4% (Clot) and 31.4% (Auto) of initial volumes were found, while it remained more stable in the BHA group (84%). At 1 week, an initial osteogenesis process could be observed in the three groups along the bone walls. At 5 weeks, despite a significant decline in the volume, newly formed bone density was higher with Clot and Auto than with BHA. At 6 months, bone densities were statistically similar in the three groups. However, after 6 months, the surface invaded by newly formed bone (regenerated area) was significantly higher when BHA was used as space filler. In the BHA group, the biomaterial area slightly decreased from 42.7% (1 week) to 40% (5 weeks) and 34.9% (6 months) and the density of the composite regenerated tissue (bone+BHA) reached >50% at 6 months. CONCLUSIONS AND CLINICAL IMPLICATIONS: The three space fillers allowed bone formation to occur. Nevertheless, augmented volumes declined in the Clot and Auto groups, while they remained stable with BHA. A slowly resorbable biomaterial might be suitable in sub-sinusal bone augmentation for preventing the re-expansion process and for augmenting the density of the regenerated tissues.

Clinical Performance of a Novel Two-Piece Abutment Concept: Results from a Prospective Study with a 1-Year Follow-Up.

Development of a stable and healthy soft-tissue barrier around dental implants is key to long-term success of implant-supported prostheses. The novel two-piece abutment concept shifts the prosthetic interface to the soft-tissue level to protect bone interface/connective tissue during the healing phase and restorative procedures. This prospective study included 72 patients treated with 106 implants to support a single-tooth or a three-unit bridge restored with two-piece abutments. The evaluation included marginal bone level change (MBLC), implant and prosthetic survival, soft-tissue health including keratinized mucosa height and mucosal margin position, patient quality of life (QoL) and satisfaction, and clinician satisfaction and ease-of-use rating of the concept. Mean MBLC from implant placement to 1 year was -0.36 ± 1.26 mm (n = 89), the 1-year implant and prosthetic survival rates were 97.1 and 96.7%, respectively, while keratinized mucosa height increased from 2.9 ± 1.2 mm at prosthetic delivery to 3.2 ± 1.3 mm, and mucosal margin migrated coronally by 0.49 ± 0.61 mm by 1 year. Patient satisfaction and QoL were high. Clinicians were satisfied with the esthetic and functional results and rated the concept as easy to use. In conclusion, the novel two-piece abutment concept promotes good peri-implant tissue health, while providing an easy-to-use workflow and high treatment satisfaction to both patients and clinicians.

Assessment of Disinfection Potential of Q-Switch Nd: YAG Laser on Contaminated Titanium Implant Surfaces.

Peri-implantitis (PI) is a relatively frequent pathology that compromises the overall survival of the dental implant. Adjunctive approaches for the conventional mechanical debridement are being suggested to optimize the treatment of PI. The goal of the study was the assessment of the disinfection potential of the Q-Switch Nd: YAG laser on contaminated titanium implant surfaces. A total of 72 sterile titanium discs were used and divided into three groups: 24 contaminated titanium discs treated with the laser (study Group L), 24 contaminated titanium discs with no treatment (control 1-Group C), and 24 sterile titanium discs with no treatment (control 2-Group S). Multi-species biofilm was used: Porphyromonas gingivalis, Fusobacterium nucleatum, Aggregatibacter actinomycetemcomitans, Streptococcus mutans, Streptococcus sobrinus, and Prevotella intermedia. Commensal bacteria were included also: Actinomyces naeslundii, Actinomyces viscosus, Streptococcus cristatus, Streptococcus gordonii, Streptococcus mitis, Streptococcus oralis, Streptococcus sanguinis, Streptococcus parasanguinis, and Veillonella parvula. Parameters delivered per pulse on the targeted surfaces of the titanium discs were an energy density of 0.597 J/cm2 each pulse, a pulse power of 270 mW, a laser beam spot of 2.4 mm in diameter, and a rate of repetition of 10 Hertz (Hz) for a pulse duration of 6 nanoseconds (ns). The mode was no contact, and a distance of 500 micrometers was used with a total time of irradiation equal to 2 s (s). The collection of microbiological samples was made for all groups; colony-forming units (CFU) were identified by two different practitioners, and the average of their examinations was considered for each sample. The average of the TBC (CFU/mL) was calculated for each group. Values were 0.000 CFU/mL, 4767 CFU/mL, and 0.000 CFU/mL for Group L, Group C, and Group S, respectively. Therefore, the suggested treatment protocol was able to provoke a total disinfection of the contaminated titanium surfaces. A statistical difference was only found between Group L vs. Group C and between Group S vs. Group C. The difference was not significant between Group S and Group L. In conclusion, the present study confirmed that the Q-Switch Nd: YAG laser under our specific conditions can provide a total disinfection of the contaminated titanium surfaces.

One-step approach for implant placement and subantral bone regeneration using bovine hydroxyapatite: a 2- to 6-year follow-up study.

PURPOSE: Pneumatized sinuses in the posterior maxilla often make implant placement difficult or impossible. A sinus lifting procedure can reliably augment the bone height, with the highest success rates reported when two-stage implants are placed 6 to 9 months later. The aim of this study was to evaluate the clinical reliability of a shortened approach in which nonsubmerged implants were placed at the time of sinus augmentation. MATERIALS AND METHODS: All patients treated with sinus floor elevation and simultaneous implant placement at the authors' institution from 1999 to 2004 were retrospectively selected for a long-term follow-up study. Sinus elevation was considered when the remaining subantral bone height did not reach 6 mm in one or more implant sites. The lateral window technique was performed using bovine hydroxyapatite as a filler, and nonsubmerged implants were placed immediately. Implant and prosthodontic survival rates, as well as biologic and prosthodontic complications, were evaluated 2 to 6 years after loading. RESULTS: In a sample of 40 patients, 50 subantral bone augmentations were performed and 102 implants were placed using the one-stage approach. One implant remained submerged because of a lack of primary stability. No sinusitis was noted. Only two implants were lost before loading. No implants failed after the definitive restorations were placed, leading to a 98% implant survival rate and 100% prosthodontic survival rate after 2 to 6 years. CONCLUSIONS: Subantral bone regeneration with bovine hydroxyapatite as a space filler is an effective and safe procedure allowing high survival rates of implants placed in the posterior maxilla. If the remaining bone is sufficient to ensure primary stability, implant placement can be performed simultaneously with sinus lifting, and even in a nonsubmerged fashion.

Hard and soft tissue analysis of alveolar ridge preservation in esthetic zone using deproteinized bovine bone mineral and a saddle connective tissue graft: A long-term prospective case series.

AIM: Although alveolar ridge preservation (ARP) procedures appear to limit bone resorption after dental extraction, long-term outcomes remain limited. The objective of this prospective case series was to evaluate the long-term hard and soft tissue changes after ARP procedure in the aesthetic area, using deproteinized bovine bone mineral (DBBM) and saddle connective tissue graft. MATERIALS AND METHODS: Fifteen patients were subjected to ARP and impressions and CT scans were taken at baseline and 3 months. After 5 to 7 years, a secondary long-term clinical and radiological analysis was carried out. Horizontal alveolar bone changes, soft tissue profiles and implant outcomes were assessed. RESULTS: Although a limited hard and soft tissue remodeling occurred during the first 3 months after ARP, from 3 months to the long-term evaluation, the alveolar bone dimensions remained stable and the soft tissue profiles significantly increased, in the more cervical levels. The implant survival rate after 5 to 7 years yielded 100% and peri-implant bone levels and soft tissue health were good. CONCLUSION: Within the limits of the study, the present data confirms the long-term effectiveness of ARP using DBBM and a saddle connective tissue graft offering stable hard and soft tissue conditions up to 5 to 7 years.