Autologous bone harvested during implant bed preparation: A randomized clinical trial comparing high-speed drilling with irrigation versus low-speed drilling without irrigation.

OBJECTIVE: To compare collected bone weight and the frequency of autologous bone harvesting from the flutes of surgical drills used for implant bed preparation using two different drilling techniques. A comparative evaluation of radiographic bone density and bone quality was also made. MATERIALS AND METHODS: A randomized clinical trial was made of 66 dental implants in patients with a single posterior edentulous site. The compared drilling techniques were high-speed drilling with irrigation (control group) and low-speed drilling without irrigation (test group). The bone collected in both groups was dried and weighed with a precise electronic balance. The frequency of harvesting was calculated. The median radiographic bone density of each implant site was measured using cone-beam computed tomography (CBCT) pixel values. Patient sex, age, implant position and dimensions, as well as the last drill diameter were analyzed as independent variables. The level of significance was 5%. RESULTS: The harvesting of bone chips from drill flutes proved possible in 51.5% of the procedures in the control group and in 100% in the test group (p < 0.001). There were also statistically significant differences in bone weight between the control group (6.7 ± 10.6 mg) and the test group (41.9 ± 30.3 mg) (p < 0.001). The CBCT pixel values were directly correlated with the collected bone weight in both groups. The median radiographic bone density, arch and last drill diameter were significantly associated with harvesting bone frequency and collected bone weight (p < 0.05). CONCLUSIONS: Our findings suggest that the frequency and weight of autologous bone harvested from drills are greater with low-speed drilling without irrigation than with high-speed drilling with irrigation. Radiographic bone density, arch and last drill diameter also significantly influenced the harvesting outcomes.

A clinical protocol for immediate dental implant placement in post-extraction-infected sites decontaminated with Er,Cr:YSGG laser.

BACKGROUND: Placement of dental implants into fresh extraction sockets offers some advantages, such as reduced treatment times and enhanced patient comfort. The Er,Cr:YSGG (Erbium, Chromium-doped: Yttrium, Scandium, Gallium, and Garnet) laser can significantly reduce bacterial concentration after the extraction of a compromised tooth. The aim of this article is to provide a clinical protocol for the management of implants placed in infected extraction sites decontaminated with Er,Cr:YSGG laser. METHODS: A compromised tooth, which was an abutment for a fixed bridge, with clinical and radiological signs of infection was extracted. The infected site was treated and decontaminated with an Er,Cr:YSGG laser device (Biolase iPlus®) and two implants (Straumann®) were placed in the same surgery, in order to rehabilitate the edentulous area. The intervention was completed by tissue regeneration with biomaterials. RESULTS: Prosthetic rehabilitation after the surgical phase allowed us to provide correct function and satisfactory esthetics. In the follow-up visit, clinicians found good tissue healing and did not observe any complications, such as implant loss or peri-implantitis. The technique used in our study is repeatable and predictable, but patient selection is very important for this type of protocol as the presence of contraindications can lead to failure. The photoacoustic effect exerted by this type of laser has been proven to be effective against many pathogens. Several authors have previously demonstrated the effectiveness of this technique. CONCLUSIONS: Immediate implantation in infected sites decontaminated with Er,Cr:YSGG laser does not seem to contribute to an increased risk of failure; however, it is necessary to follow a certain set of protocols and procedures to prevent peri-implantitis and other complications.

Comparison of patient-centered outcomes measures between low-speed drilling without irrigation and high-speed drilling with irrigation: A randomized clinical trial.

OBJECTIVE: To compare patient satisfaction during surgery, postoperative pain and inflammation and quality of life between high-speed drilling with irrigation and low-speed drilling without irrigation for implant bed preparation. MATERIALS AND METHODS: Sixty-six posterior single edentulous patients were included in a randomized controlled clinical trial. Implant beds were created using high-speed drilling with irrigation (control group) or low-speed drilling without irrigation (test group). Patient satisfaction during surgery (in relation to drilling-time perception, vibration, pressure, noise, comfort, and drowning sensation) and postoperative pain and inflammation were evaluated using a 100-mm visual analogue scale (VAS)-based questionnaire. Quality of life was analyzed with a Likert scale (in relation to mouth opening, chewing, speaking, sleeping, daily routine, and job). The follow-up period was 7 days. RESULTS: Patient satisfaction in relation to drilling-time perception, vibration, pressure, and noise did not show statistically significant differences (p > .05). The highest scores of drowning sensation (p < .05) were correlated (moderate correlation (r = .57)) with lowest scores of comfort (p < .005). Both postoperative pain and inflammation means were significantly higher in the control group than in the test group. No significant differences in quality of life were observed during the postoperative period (p > .05). CONCLUSION: Low-speed drilling without irrigation for single implant site preparation was more comfortable for patients than high-speed drilling with irrigation, due to the correlation between important drowning sensation and low perceived comfort. Postoperative pain and inflammation were lower for low-speed drilling without irrigation. Further studies are needed to validate or refute these results.

Ultrasonic osteotomy and regeneration with A-PRF+ for periapical surgery of a mandibular molar with root cyst perforating the lingual osseous cortex: A case report.

Background: Periapical surgery is a complex dental procedure that remains a considerable challenge in clinical practice. The use of APRF+ membranes and piezoelectric osteotomy help to improve outcomes and increase the efficiency and speed of recovery. Material and Methods: This case report describes a 20 years-old man with a periapical lesion which perforated the lingual cortex in a lower mandibular molar. A periapical surgery was performed with endoscope magnification and ultrasonic osteotomy. Apicectomy and retrograde cavities were performed using a piezoelectric scalpel and sealed using a bioceramic sealer. The osteolytic defect was filled with A-PRF+ membranes and the bone cortex was repositioned trough a micro-screw. Results: The histological analysis concluded an inflammatory odontogenic cyst. The postoperative period was uneventful with pain and mild oedema until the fourth day. Short-term follow-up showed the beginnings of bone regeneration and correct healing of the surgery without periodontal defects. Two-year follow-up showed favorable results and regeneration of the bone defect. Conclusions: Periapical surgery with magnification, ultrasonic osteotomy repositioning and application of A-PRF+ membranes as an adjuvant proved to be an effective approach for the regeneration of the osteolytic process, allowing the preservation of the tooth. Promising short and long-term results were shown for this case report. Key words:Periapical surgery, osteotomy, ultrasound, A-PRF+.

Influence of Splint Support on the Precision of Static Totally Guided Dental Implant Surgery: A Systematic Review and Network Meta-analysis.

Purpose: To assess the accuracy of totally guided implant placement with static surgical splints in relation to the different types of supporting tissues (tooth, mucosa, or bone). Materials and Methods: This review was carried out following the PRISMA guidelines. An electronic search was done of the MEDLINE (PubMed), Embase, and Cochrane Library databases, without publication year or language restrictions. Results: The literature search yielded a total of 877 articles; 18 were included in the qualitative synthesis, and 16 of these articles were included in the quantitative analysis. The included studies presented a high risk of bias, except for one randomized clinical trial. The strength of the recommendations is therefore weak. In the angular deviation treatment, statistically significant differences were observed in the accuracy of the implants with tooth vs bone support: Bone support yielded 1.31 degrees greater deviation vs tooth support (SD = 0.43; 95% CI: 0.47, 2.15, P = .002). No significant differences were observed in the linear deviations. Conclusion: Tooth support proved to be significantly more precise than bone support splints. There were no differences referring to horizontal coronal deviation, horizontal apical deviation, or vertical deviation according to the type of splint support used.

Influence of the use of autogenous bone particles to close the access window after maxillary sinus floor augmentation: a micro-computed tomography and positron emission tomography study in rabbits.

AIM: The purpose of this study was to evaluate using microCT and positron emission tomography (PET) analysis, the influence on bone healing of the placement of particulate autogenous bone in the antrostomy, and in the subjacent region after maxillary sinus elevation with xenograft. MATERIAL AND METHODS: The sinus mucosa was elevated in sixteen male New Zealand rabbits and they were both grafted with a collagenated cortico-cancellous porcine bone. The antrostomy and the near subjacent region were filled with either the same xenograft (control site) or with particulate autogenous bone (test site) harvested from the tibia. The antrostomies were covered with collagen membranes. MicroCT (measured in Hounsfield Units) and microPET (kBq/cm3) using sodium fluoride infiltration (18F-NaF) were performed at the time of euthanasia that was performed after 1 and 8 weeks of healing, using 8 animals in each group. The Wilcoxon test was used for analysis. RESULTS: At the microCT analysis, after 1 and 8 weeks of healing, no statistically significant differences were found between groups. Bone increased and xenograft decreased significantly between the two periods of healing. At the microPET analysis, the percentage of bone increased significantly over time in both test and control groups and no significant differences were found between groups. CONCLUSION: The placement of autogenous bone in the antrostomy and the subjacent region after maxillary sinus elevation did not enhance bone formation compared with sites where only xenograft was used. Both microCT and microPET showed increase bone formation over time.

Immediate dental implant placement in post-extraction-infected sites decontaminated with Er,Cr:YSGG laser: a retrospective cohort study.

Dental implants placed in fresh extraction alveoli provide several advantages, including shorter treatment periods and improved patient comfort. After a compromised tooth extraction, the Er,Cr:YSGG laser can considerably reduce bacterial concentration. The objective of this controlled study conducted after at least 1 year of follow-up was to compare the use of immediate post-extraction implants in infected sites treated with laser (test group) versus conventional implants in edentulous sites (control group) through an analysis of pre- and post-operative radiographs. The study was based on a series of patients treated between 2014 and 2019, with a 1-year minimum follow-up, and up to over 4 years. An analysis of the clinical history of the treated patients and pre- and post-operative radiographs was performed to evaluate the implant success and to measure the marginal bone level (MBL). Overall, 149 implants were studied. There was only one failure in the test group (1%) and no failures in the control group. The test group gained 0.1 mm of the MBL compared to the baseline, while the control group lost 0.1 mm of the MBL. The difference between the two groups of only 0.2 mm was not statistically significant (P = 0.058). Immediate dental implants in infected sockets debrided and decontaminated using Er,Cr:YSGG laser do not appear to enhance the likelihood of failure; however, peri-implantitis and associated problems must be avoided by following a certain set of protocols and procedures.

The study of bone healing after endodontic microsurgery using cone beam computed tomography: A retrospective cohort study.

Background: The main aims of this study were to evaluate mean volume reduction, radiographic healing rate and healing outcome two years after endodontic microsurgery. The effects of certain preoperative clinical factors upon preoperative volume, volumetric changes and healing outcome were also studied. Material and Methods: A clinical database was searched for patients who had undergone endodontic microsurgery and with the availability of a cone beam computed tomography (CBCT) scan preoperatively and after a control period. Volumetric analysis of the periapical area was made to assess volumetric reduction. The modified Penn 3D criteria were applied. The relationship between preoperative volume, volumetric reduction and healing outcome and certain preoperative factors was also studied. Results: Fifty-seven cases were evaluated. Initially, the bone cavities had a median volume of 163.2 mm3, and this volume decreased by 147.7 mm3 after treatment, with a radiographic healing rate of 6.2 mm3 per month. After applying the modified Penn 3D Criteria, 53 cases were classified as successful healing (93%). Regarding the influence of the different preoperative factors, patient age and sex, dental arch and cortical bone significantly influenced preoperative volume, while only the dental arch exerted a significant influence upon volumetric changes and preoperative symptoms on healing outcome. Conclusions: The CBCT data evidenced a significant volume reduction of 79.1%, with a monthly volume reduction rate of 6.2 mm3. The success rate obtained was 93%. Patient age and sex, dental arch and cortical bone influenced preoperative volume, tooth type had an impact upon the volumetric changes, and the preoperative symptoms influenced healing outcome. Key words:Cone beam computed tomography, endodontic microsurgery, healing, lesion volume, prognostic factors.

Healing of 295 Endodontic Microsurgery Cases After Long-Term (5-9 Years) Versus Middle-Term (1-4 Years) Follow-up.

INTRODUCTION: Some evidence suggests that teeth treated with endodontic surgery and considered to have healed over the short term are seen to relapse when evaluated again after 3 or more years. However, long-term evidence is limited. This study compares healing after endodontic microsurgery over long-term (5-9 years) vs middle-term (1-4 years) follow-up and assesses the influence of different healing predictors over time. METHODS: A retrospective study was made, comparing the endodontic microsurgery healing rates after 1-4 vs 5-9 years of follow-up. Healing was assessed based on clinical and radiographic parameters. Simple binary logistic regression models were used to analyze the influence of patient age and gender, the type of tooth, previous radiographic lesion size, apical extent of previous root canal filling, the presence of a post, type of restoration, and interproximal bone level upon the endodontic microsurgery healing rate. A sensitivity analysis was used excluding cases of vertical root fracture. Two calibrated observers independently evaluated the periapical radiographs. RESULTS: A total of 332 patients (60% women and 40% men) were included in the study. Of the 332 analyzed teeth, 198 were subjected to middle-term follow-up (1-4 years), with a healing rate of 86.9%, while 134 were subjected to long-term follow-up (5-9 years), with a healing rate of 67.2%. There were no statistically significant differences in terms of gender, age, type of tooth, size of the lesion, apical extent of previous root canal filling, presence of a post, or type of restoration. The regression models identified 2 statistically significant associations: cohort and interproximal bone level (P < .05). CONCLUSIONS: A success rate of 86.9% was recorded after 1-4 years of follow-up, vs 67.2% after 5-9 years. Excluding cases of vertical root fractures, in the shortest follow-up cohort (1-4 years), the healing rate was 92.5%, vs 82.6% in the cohort with longer follow-up (5-9 years). The prognosis was influenced by the crestal bone level in relation to the cementoenamel junction of the tooth, being significantly poorer when probing depth was >3 mm mesial or distal to the treated tooth.

Is Healing of Periapical Surgery Influenced by Endoscopic Findings Detected on the Cut Root Surface?

PURPOSE: An analysis was made of the association between the endoscopic findings of the sectioned root end surface and healing of the lesion 1 year after periapical surgery, although no studies appear to have analyzed them in relation to healing after periapical surgery. METHODS: A retrospective cohort study was made of patients subjected to periapical surgery between 2011 and 2019. After apicoectomy, the root end surface was examined, evaluating the number of canals, isthmuses, dentin cracks and craze lines, opaque dentin, and gaps between the filling material and the root canal wall. An analysis (using Generalized Estimating Equation models) was made of the association between the endoscopic findings and healing evaluated by von Arx and Kurt criteria and the modified PENN 3D criteria. The possible influence of patient age and gender and the type of tooth involved on healing was evaluated. RESULTS: A total of 108 patients (114 teeth and 128 roots) were subjected to periapical surgery. Two or more canals were detected in 27.3% of the roots (8.6% not subjected to orthograde filing), and isthmuses were identified in 18%, craze lines in 7%, cracks in 3.1%, opaque dentin in 69.5%, and gaps in 53.1% of the roots. The healing rate at 1 year according to the criteria of von Arx and Kurt was 95.4% versus 82.2% according to the modified PENN 3D criteria. Failure was more common in roots with cracks, although statistical significance was not reached (odds ratio [95% confidence interval]: 0.20 [0.01 to 4.04]; P = .200). The rest of the endoscopic findings as well as patient age and gender and the type of tooth did not influence healing (P > .05). CONCLUSIONS: In the present sample, no statistically significant associations were observed between the endoscopic and healing at 1 year after periapical surgery. Failure was more common in roots with cracks, however.

Influence of the Use of a Collagen Membrane Placed on the Bone Window after Sinus Floor Augmentation-An Experimental Study in Rabbits.

BACKGROUND: We studied the influence on healing of a resorbable membrane covering the osteotomy site after maxillary sinus grafting, evaluated in different regions of the augmented area. METHODS: Maxillary sinus augmentation was performed in 24 New Zealand rabbits. Osteotomy, 4 × 6 mm, were performed bilaterally. A collagenated cortico-cancellous porcine bone was used to fill the elevated region. A collagen membrane was randomly placed over the osteotomy site on one side (MG), and the other side was left uncovered (NMG). The animals were euthanized after 2, 4, and 8 weeks; and histomorphometric analysis was performed in eight different regions. RESULTS: New bone percentages were similar in both groups. There were no statistically significant differences. In MG, the overall percentages were 15.6 ± 7.3%, 22.9 ± 6.1%, and 24.9 ± 12.0% after 2, 4, and 8 weeks, respectively. In NMG, the percentages were 11.2 ± 4.5%, 24.1 ± 5.7%, and 24.5 ± 15.7%, respectively. The proportions of new bone in the various regions after 8 weeks were 31 ± 8.9% and 29.9 ± 9.1% in the bone walls region, 25 ± 10.1% and 32.8 ± 9.1% in the submucosa region, 22.6 ± 21.6% and 10.9 ± 11.5 in the middle region, 17.3 ± 14% and 13.4 ± 9.8% in the close-to-window region, and 21.8 ± 11.6%, 19.1 ± 6.4% in the osteotomy region-for MG and NMG, respectively. CONCLUSIONS: In both groups the greatest amounts of bone formation occurred near to the pre-existing bone walls, followed by the sub-mucosa region. The smallest amounts were found in the close-to-window region, followed by the central region. The placement of a collagen membrane to cover the osteotomy site did not influence the amount of new bone formation after sinus grafting.

Factors influencing the aesthetics of smile: An observational study on clinical assessment and patient's perception.

AIM: To clinically assess the aesthetics of smile and the possible influencing factors. MATERIALS AND METHODS: In this explorative study, an initial questionnaire on demographic variables and perception of own quality of smile (Visual Analogue Scale) was administered by a first examiner. A second blinded assessor examined all patients and recorded clinical data. In addition, for each patient, the Smile Aesthetic Index (SEI) was calculated. Descriptive statistics and multilevel logistic models were performed. RESULTS: One hundred consecutive subjects were enrolled. The mean SEI was 8.4 ± 1.2, while the mean patient's perception of smile was 7.1 ± 2.0. However, they did not correlate (r = 0.16 from -0.04 to 0.34; p = .12). Gingival recessions were perceived by 21.9% of subjects, tooth alignment by 38.6%, tooth dyschromia by 34.3%, and missing papilla/diastema by 26.7%. In particular, gingival recessions were perceived when they were deeper (p = .0342), located in the upper jaw (p = .0223), and corresponding to incisors (p < .0001) and canines (p = .0159) with respect to molars. CONCLUSIONS: Clinical assessment and patient perception represent two important diagnostic phases. However, there is no correlation between them. Attention should be given to specific variables to provide the most comprehensive aesthetic analysis of smile.

Comparison of the diagnostic efficacy of 2D radiography and cone beam computed tomography in persistent apical periodontal disease: A PRISMA-DTA systematic review and meta-analysis.

OBJECTIVE: The objective of this study was to answer the question: Do conventional radiographs (periapical/panoramic) afford better diagnostic outcomes than cone beam computed tomography (CBCT) as a complement for clinical diagnosis of apical lesions with persistent apical periodontitis or disease after root canal treatment? STUDY DESIGN: Five electronic databases were searched and provided information to enable construction of a table to determine primary diagnostic measures and secondary parameters. The evidence was appraised with the Quality Assessment of Diagnostic Accuracy Studies tool and GRADEpro software. RESULTS: Twenty-seven articles (9903 diagnostic images) were included. The pooled sensitivity, specificity, area under the receiver operating characteristic curve (AUCROC), positive predictive value, negative predictive value, negative likelihood ratio, and accuracy were 0.58, 1, 0.77, 1, 0.68, 0.45, and 0.79, respectively. CONCLUSIONS: Moderate certainty evidence suggested that conventional radiographs showed poor sensitivity and excellent specificity but good diagnostic performance in terms of AUCROC and accuracy. Sensitivity, AUCROC, and negative likelihood ratio values could be reduced if the time elapsed to diagnosis after root canal treatment exceeded 5 years. The use of CBCT with a reduced field of view or a 2D radiographic technique should be weighed considering patient-specific and indication-oriented criteria as taking precedence over the therapeutic goal.

Culturomic and quantitative real-time-polymerase chain reaction analyses for early contamination of abutments with different surfaces: A randomized clinical trial.

BACKGROUND: Rough and/or plasma-activated abutments seem to be able to increase soft tissue adhesion and stability; however, limited evidence is available about bacterial contamination differences. PURPOSE: The aim was to investigate the oral microbiota on four dental abutments with different surfaces by quantitative real-time polymerase chain reaction (qRT-PCR) and culturomic approach. METHODS: Forty patients needing a single implant rehabilitation were involved in the study. Forty healing abutments, especially designed for the study, were divided into four groups according to the surface topography (1. machined [MAC], 2. machined plasma of argon treated [plasmaMAC], 3. ultrathin threaded microsurface [UTM], 4. UTM plasma of argon treated [Plasma UTM]). Random assignment was performed according to predefined randomization tables. All patients underwent surgical intervention for implant and contextual healing abutment positioning. After 2 months of healing, a sterile cotton swab was used for microbiological sampling for culturomics, while sterile paper points inserted into the sulcus were used for qRT-PCR. RESULTS: At the end of the study, 36 patients completed all procedures and a total of 36 abutments (9 per group) were analyzed. qRT-PCR retrieved data for 23 bacterial species whereas culturomics revealed the presence of 74 different bacteria, most of them not routinely included into oral cavity microbiological kits of analysis or never found before in the oral microenvironment. No statistically significant differences emerged analyzing the four different surfaces (p = 0.053). On the contrary, higher total and specific bacterial counts were detected in the plasma-treated surfaces compared to the untreated ones (p = 0.021). CONCLUSIONS: Abutments with different topographies and surface treatments resulted contaminated by similar oral bacterial flora. Abutments with moderately rough surface were not associated with a greater bacterial adhesion compared to machined ones. Conversely, more bacteria were found around plasma-treated abutments. Furthermore, data reported suggested to include new species not previously sought in the routine analyses of the oral bacterial microflora.

Soft tissue integration of different abutment surfaces: An experimental study with histological analysis.

OBJECTIVE: To evaluate whether abutment surface and surface bio-activation have an effect on soft tissue morphogenesis. MATERIALS AND METHODS: 36 patients (36 implants) were included. Abutments were randomly divided into 4 groups (n = 9): Smooth Surface-MAChined (MAC), Ultrathin Threaded Microsurface (UTM), MAC Plasma of Argon activated (Plasma-MAC), and UTM Plasma of Argon activated (Plasma-UTM). After 2 months of healing, soft tissue samples were collected and prepared for histological analysis. The margin of the peri-implant mucosa (PM), the apical extension of the barrier epithelium (aJE), and the apical location of the abutment (AM) were identified. Significances of differences among groups were tested by means of the Kruskal-Wallis test and between pairs of results by means of the Mann-Whitney test. RESULTS: The mean (SD) vertical dimension of the mucosa was 2.5mm (1.0), including a connective tissue portion (CTP) of 0.8mm (0.8) in the MAC group; 3.6mm (0.2) with a CTP of 1.6mm (0.4) in the Plasma-MAC group; 3.2mm (1.0), with a CPT of 0.5mm (0.6) in the UTM; and 3.3mm (0.8), with a CPT of 0.9mm (0.7) in the Plasma-UTM group. Statistically significant differences were observed in the aJE-AM height and PM-aJE profile among the four experimental groups (p = .042 and p = .039, respectively). The Mann-Whitney test indicated differences between the Plasma-abutments and the untreated abutments both for PM-AM (p = .025) and AjE-AM (p = .021). The differences appeared more evident when the preoperative soft tissue thickness was ≤2mm. CONCLUSIONS: Within its limits, the study demonstrated a favorable effect of the plasma treatment on the connective tissue portion tissues. Plasma-MAC group highlighted the best performance. This behavior appeared strictly correlated with the soft tissue thickness.

Low-speed drilling without irrigation versus conventional drilling for dental implant osteotomy preparation: a systematic review.

PURPOSE: This paper aims to review the evidence comparing low-speed drilling without irrigation versus conventional drilling for dental implant osteotomy preparation. MATERIALS AND METHODS: A systematic review was carried out based on the PRISMA statement. Four databases and gray literature were searched up to November 2020. In vitro, animal, and clinical studies were included. The variables were temperature change, drilling time, quantity of harvested bone, osteotomy precision, marginal bone loss, implant success rate, osseointegration, and the histomorphologic characteristics and cellularity of the osteotomy and of the harvested bone. Different tools for the assessment of bias were applied for each study design. RESULTS: A total of 626 articles were identified, of which 13 were included. Both low-speed drilling without irrigation (test group) and conventional drilling (control group) maintained temperatures below the critical temperature of 47 °C. The test group yielded a greater quantity and more beneficial cellular and histomorphologic properties of harvested bone, with a longer drilling time and greater osteotomy precision (p < 0.05). No significant results were obtained regarding drill wear, osseointegration, marginal bone loss, implant success rate, and histomorphology of the dental implant osteotomy (p > 0.05). The results, in particular on the osteotomy precision and quantity of harvested bone chips, should be interpreted with caution because outcomes are based in only one in vitro study. CONCLUSIONS: Low-speed drilling without irrigation seems to be comparable to conventional drilling in preparing dental implant osteotomies. In some situations, low-speed drilling without irrigation might offer advantages over conventional drilling. The results should be interpreted with caution due to the low percentage of clinical human studies. Accordingly, more clinical studies are needed to improve the scientific evidence on this topic. CLINICAL RELEVANCE: The low-speed drilling without irrigation is a valid technique for dental implant osteotomy preparation. Its higher quantity and quality of harvested autologous bone might be particularly beneficial in cases of dental implant placement with minor simultaneous bone regeneration.

Facial alveolar bone thickness and modifying factors of anterior maxillary teeth: a systematic review and meta-analysis of cone-beam computed tomography studies.

BACKGROUND: Understanding the anatomy of the facial alveolar bone (FAB), provides a prognostic tool for estimating the degree of dimensional ridge alterations after tooth extraction. This systematic review and meta-analysis aims to determine the FAB thickness and modifying factors of anterior maxillary teeth measured by CBCT scans. A secondary objective was to assess the facial distance from the cementoenamel junction (CEJ) to the bone crest. METHODS: An electronic search was made of Medline, Embase, Web of Science, Cochrane Library and Google Scholar up to December 2019. Studies that analyze and quantitatively compare FAB thickness at maxillary teeth by CBCT scans were included. The methodological quality of the included studies was appraised using the ROBINS-I tool and the overall meta-evidence certainty using the GRADE approach. A single means random-effects meta-analysis was performed to obtain the weighted mean for 95% confidence interval. A meta-regression of covariates and subgroup analysis was conducted. The nullity Qh test and I2 index for heterogeneity was estimated. RESULTS: 2560 potentially relevant articles were recorded from which 29 studies were selected for the qualitative analysis, including 17,321 teeth. Seventeen studies considered the facial bone crest, and 12 the CEJ as a reference point for their measurements. Mean FAB thickness was ≤ 1 mm in maxillary incisors and canines (0.75-1.05 mm) and 1-2 mm in premolars. Patients over 50 years of age, females and thin gingival phenotype was associated with thinner FAB at some apico-coronal locations of maxillary incisors and canines. The geographical setting was an effect modifier that could explain up to 87% of the heterogeneity in FAB thickness, being Asian populations that showed the lowest FAB thickness values. The CEJ-bone crest distance was 2-2.5 mm in all teeth analyzed. Population over 50 years of age exhibited greater CEJ-bone crest distances, and males also showed a trend for greater distance. Evidence certainty has shown moderate quality in most analysis subsets. CONCLUSIONS: Facial alveolar bone at anterior maxillary teeth is thin, heterogeneous in width along its apico-coronal dimensions, and increases in thickness in maxillary premolars. The CEJ-bone crest distance presented homogeneous and similar values in all teeth analyzed.

Standardization of three-dimensional pose of cylindrical implants from intraoral radiographs: a preliminary study.

BACKGROUND: To introduce a theoretical solution to a posteriori describe the pose of a cylindrical dental fixture as appearing on radiographs; to experimentally validate the method described. METHODS: The pose of a conventional dental implant was described by a triplet of angles (phi-pitch, theta-roll, and psi-yaw) which was calculated throughout vector analysis. Radiographic- and simulated-image obtained with an algorithm were compared to test effectiveness, reproducibility, and accuracy of the method. The length of the dental implant as appearing on the simulated image was calculated by the trigonometric function and then compared with real length as it appeared on a two-dimensional radiograph. RESULTS: Twenty radiographs were analyzed for the present in silico and retrospective study. Among 40 fittings, 37 resulted as resolved with residuals ≤ 1 mm. Similar results were obtained for radiographic and simulated implants with absolute errors of - 1.1° ± 3.9° for phi; - 0.9° ± 4.1° for theta; 0° ± 1.1° for psi. The real and simulated length of the implants appeared to be heavily correlated. Linear dependence was verified by the results of the robust linear regression: 0.9757 (slope), + 0.1344 mm (intercept), and an adjusted coefficient of determination of 0.9054. CONCLUSIONS: The method allowed clinicians to calculate, a posteriori, a single real triplet of angles (phi, theta, psi) by analyzing a two-dimensional radiograph and to identify cases where standardization of repeated intraoral radiographies was not achieved. The a posteriori standardization of two-dimensional radiographs could allowed the clinicians to minimize the patient's exposure to ionizing radiations for the measurement of marginal bone levels around dental implants.

In-vitro fatigue and fracture performance of three different ferrulized implant connections used in fixed prosthesis.

BACKGROUND/PURPOSE: The aim of the present in vitro study was to evaluate fatigue resistance of dental fixtures in three different types of fixture/abutment finishing line. MATERIALS AND METHODS: Transmucosal dental implants, with or without ferrulized neck, underwent fatigue tests (static and dynamic load) using the following standard protocol: UNI EN ISO 14801:2016. Two types of loading devices (screw- or cement-retained restoration) were also tested, and fatigue cycle tests were run to failure. Data of static and dynamic load tests were analyzed by proper statistical methods. RESULTS: Following standard protocol for fatigue testing, the ILC type (Implant Level with ferrulized neck and cement-retained crown) showed a non-significant but higher Ultimate Failure Load (UFL = 445.7 N) compared to AL type (Abutment Level without ferrule effect, 421.6 N) and ILS type (Implant Level with ferrulized neck and Screw-retained crown, 362.8 N). No fracture of the titanium-base was registered in the tested specimens during the static loadings. Permanent deformations of the materials were observed. CONCLUSION: The number of cycles to either fracture or deformation (higher than 4 mm) occurring during fatigue tests showed that the stress rupture curve of the materials in group ILS appeared to be significantly different from those of the ILC and AL groups (p-values < 0.01): much higher life of one-half order of magnitude.