Bone collected during dental implant surgery: a clinical and histological study

Bone traps vary in design, although the effect of pore size on the nature of the debris collected in vivo has not yet been established. The aims of this study were 1) to compare the clinical performance of two bone collectors during implant surgery, ii) to establish the mass of tissue collected by each device, and iii) to characterize the nature of the collected debris. Thirty-eight patients (paired for implant site) were categorised into three clinical groups according to the site and the number of implants they were to receive. Patients underwent bone collection with the Frios bone trap or the Osseous Coagulum Trap according to a randomisation sequence. The samples were fixed in formalin, frozen, freeze-dried and weighed. Material from each sample was embedded in paraffin wax and stained with haematoxylin and eosin. All sections were examined by optical microscopy and the proportion of bone to coagulum was established histomorphometrically. During surgery, the Frios bone trap blocked once and the Osseous Coagulum Trap blocked 11 times. In all cases where blockage occurred, excess coagulum was apparent. All the samples that were collected by the Frios bone trap contained bone and coagulum, with a mean proportion of 90.6% bone. With regard to the Osseous Coagulum Trap, one sample contained no bone and two samples contained only trace amounts of bone; the remaining samples contained a mean proportion of 67.3% bone. Pore size affects both clinical performance and the histological composition of the debris collected, and this might have important implications if used as an augmentation material.     

数字化导板引导下全口种植即刻负重可行性与精准度的研究

目的 探究数字化导板引导下全口种植即刻负荷的可行性,根据影像学数据评价导板引导的种植精准度,探讨可能影响植体位置精度的相关因素.方法 按照准入排除标准,收集2017年至2019年使用数字化导板引导下的全口种植即刻负重固定修复患者16例(98枚植体),跟踪随访患者评价长期的临床修复效果.利用CBCT数据测量30颗植体实际...     

Accuracy of a computerized tomography-guided template-assisted implant placement system: an in vitro study

Objectives: To evaluate the accuracy of computer-assisted 3D planning and implant insertion using computerized tomography (CT).
Materials and methods: Nine implants were planned on pre-operative CTs of six resin models, which were acquired with radiographic templates, using a planning software (E implants). Each resin model contained three pre-existing control implants (C implants). Radiographic templates were converted into operative guides containing 4.8-mm-diameter titanium sleeves. A single set of insertable sleeves was used for consecutively drilling the six models, followed by implant insertion through the guide sleeves. Models were further divided into group A (the first three models) and group B (the last three models). Post-operative CTs were used to compare implant positions with pre-operative planned positions. Statistical analysis included the Mann–Whitney U test for E and C implants and the Wilcoxon's signed ranks test for groups A and B.
Results: The mean apex depth deviations for E and C implants [0.49 mm±0.36 standard deviation (SD) and 0.32 mm±0.21 SD, respectively], and the mean apex radial deviations (0.63 mm±0.38 SD and 0.49 mm±0.17 SD, respectively) were similar ( P >0.05). The mean angulation deviations for E and C implants were 2.17±1.06°SD and 1.33±0.69°SD, P <0.05. E implant deviations of all the parameters in group A were significantly smaller than E implant deviations in group B.
Conclusions: Computer-assisted implant planning and insertion provides good accuracy. Deviations are mainly related to system and reproducibility errors. Multiple use of drills and titanium sleeves significantly reduces system accuracy.     

Microbial analysis of bone collected during implant surgery: a clinical and laboratory study

Dental implant surgery produces bone debris which can be used to correct bone defects in the "simultaneous-augmentation" technique. However, this debris is potentially contaminated with oral bacteria. Therefore, this study examined bone debris collected during dental implant surgery in order 1) to identify the microbial contaminants and 2) to compare the effects of two different aspiration protocols on the levels of microbial contamination. Twenty-four partially dentate patients were randomly allocated into two equal groups and underwent bone collection using the Frios Bone Collector during surgery to insert two endosseous dental implants. In group S (using a stringent aspiration protocol), bone collection occurred within the surgical site only. In group NS (utilizing a non-stringent aspiration protocol), bone collection and tissue fluid control was achieved using the same suction tip. Bone samples were immediately transported for microbial analysis. Colonial and microscopic morphology, gaseous requirements and identification kits were utilized for identification of the isolated microbes. Twenty-eight species were identified including a number associated with disease, in particular, Enterococcus faecalis and Staphylococcus epidermidis as well as the anaerobes Actinomyces odontolyticus, Eubacterium sp., Prevotella intermedia, Propionibacterium propionicum and Peptostreptococcus asaccharolyticus. In group S (stringent aspiration protocol), significantly fewer organisms were found than in group NS, the non-stringent aspiration protocol (P=0.001). Gram-positive cocci dominated the isolates from both groups. It is concluded that if bone debris is collected for implantation around dental implants, it should be collected with a stringent aspiration protocol (within the surgical site only) to minimize bacterial contaminants.     

Sinus floor elevation via the maxillary premolar extraction socket with immediate implant placement: a case series

Background: When immediate implant placement is considered for teeth with close proximity to the sinus floor, apical extension of the osteotomy is significantly limited, and often a staged approach is used. Implant placement into fresh extraction sockets and sinus floor manipulation using bone‐added osteotome sinus floor elevation with implant placement are techniques most often used independently or sequentially. Very few reports have described the combined use of immediate implant placement in fresh sockets and the bone‐added osteotome sinus floor elevation technique. Methods: We present five cases in which a maxillary premolar was extracted and an implant placed into the extraction site with simultaneous abfracture of the sinus floor using osteotomes. All teeth were extracted atraumatically, and sockets carefully debrided and checked for integrity of the walls. After ideal osteotomy preparation, particulate bone graft was placed in the osteotomy and appropriately sized osteotomes were used for sinus floor elevation. After sufficient elevation, implant placement was completed and particulate bone was packed in the bone–implant gap when indicated. Results: All implants were restored after a minimum healing period of 6 months. At the time of final restoration, bone was seen surrounding the implants from the apical portion to the most coronal thread. All five implants healed without complications and were in function for periods ranging from 6 to 12 months. Conclusions: Immediate implant placement with simultaneous osteotome sinus floor elevation is an advantageous combination of two successfully used techniques. This combined approach can significantly reduce the treatment time for implant therapy in teeth with close sinus proximity and provide the operator with the ability to place implants of desired length.     

The speed of sound correlates with implant insertion torque in rabbit bone: an in vitro experiment

Objectives: This study investigated the correlation of quantitative ultrasound with bone quality as evaluable from implant final insertion torque. Material and methods: Implants were planned at diaphyses (group 1) and epiphyses (group 2) of 16 rabbit femurs where amplitude‐dependent speed of sound (Ad‐SOS) was measured. The insertion torque from 7‐mm‐long implants placed at planned sites was recorded. The correlation between cutting torque and Ad‐SOS was evaluated using Spearman's coefficient. Results: Statistics were based on data from 15 diaphyses and 13 epiphyses. The mean insertion torque was 8.8 N cm while the mean Ad‐SOS was 1710.9 m/s. A negative correlation resulted between insertion torque and Ad‐SOS. Conclusions: In the rabbit bone model investigated, quantitative ultrasound correlates inversely with implant insertion torque. Although this correlation remains to be verified in humans because rabbit femur does not convincingly represents different human bone qualities, it seems that ultrasound could convey potentially useful, pre‐surgical, site‐specific, non‐invasive information on bone mechanical characteristics therefore deserving further research efforts. To cite this article:
Veltri M, Valenti R, Ceccarelli E, Balleri P, Nuti R, Ferrari M. The speed of sound correlates with implant insertion torque in rabbit bone: an in vitro experiment.
Clin. Oral Impl. Res. 21 , 2010; 751–755.
doi: 10.1111/j.1600‐0501.2009.01873.x     

Bone heat generated using conventional implant drills versus piezosurgery unit during apical cortical plate perforation

1 Background

The apical portion of the implant osteotomy receives less irrigation and cooling during surgical preparation. High bone temperature, above the critical 10°C threshold, may impair osseointegration, particularly around dense cortical bone. The aim of this study was to evaluate the apical cortical plate temperature increase with two different devices and pressure loads in a porcine rib ex vivo model.

2 Methods

A total of 24 implant sites were prepared on porcine ribs, divided into 4 groups of 6 samples each, according to the device used (conventional drill system or piezosurgery) and pressure load applied (1,000 g or 1,500 g). A rubber dam was used to isolate the apical cortical plate from the cooling effect of irrigation. Temperature variation measurements were taken using an infrared thermometer.

3 Results

The piezosurgery unit was two times more likely to increase the osteotomy temperature by 10°C (OR = 2; 95% CI 1.136, 3.522; P < 0.05). The average temperature increase was 0.07°C (SD = 0.10) for group 1 (drill system 1,000 g); 0.22°C (SD = 0.26) for group 2 (drill system 1,500 g); 9.18°C (SD = 4.51) for group 3 (piezosurgery 1,000 g); and 8.17°C (SD = 6.12) for group 4 (piezosurgery 1,500 g). The piezosurgery site preparation had significantly higher temperature increase than did the conventional drill site preparation (P < 0.05). There was no statistically significant difference in temperature change between the two pressure loads applied (P = 0.78). Temperature increases exceeded the critical 10°C threshold in half of the samples prepared with the piezoelectric device.

4 Conclusions

Bone overheating using a piezosurgery unit is a potential risk during implant site preparation. The piezosurgical device resulted in significantly higher temperatures than did conventional drilling at the apical cortical portion of the osteotomy. The temperature increase was often higher than the critical 10°C threshold.     

Thermal changes and drill wear in bovine bone during implant site preparation. A comparative in vitro study: twisted stainless steel and ceramic drills

Objectives: The purpose was to assess thermal changes and drill wear in bovine bone tissue with the use of twisted stainless steel and zirconia‐based drills, during implant site preparation. Methods: A total of 100 implant site preparations were performed on bovine ribs using a surgical unit linked to a testing device, in order to standardize/simulate implant drilling procedures. Bone temperature variations and drilling force were recorded when drilling at a depth of 8 and 10 mm. A constant irrigation of 50 ml/min. (21±1°C) and drilling speed of 800 r.p.m. were used. Scanning electron microscopy analysis was preformed prior and after drilling. Results: Mean temperature increase with both drills at 8 mm was 0.9°C and at 10 mm was 2°C (P<0.0001). Statistical significant higher bone temperatures were obtained with stainless steel drill (1.6°C), when comparing with the ceramic drill (1.3°C) (P<0.05). Temperature increase was correlated with higher number of perforations (P<0.05) and drilling load applied. There was no significant association between drilling force applied and temperature increase by either drill or at either depth. No severe signs of wear of either drill were detected after 50 uses. Conclusions: Drill material and design, number of uses, depth and drilling load applied appear to influence bone temperature variations during implant site preparation. Drilling depth was a predominant factor in bone temperature increase. Both drills can be used up to 50 times without producing harmful temperatures to bone tissue or severe signs of wear and deformation. To cite this article:
Oliveira N, Alaejos‐Algarra F, Mareque‐Bueno J, Ferrés‐Padró E, Hernández‐Alfaro F. Thermal changes and drill wear in bovine bone during implant site preparation. A comparative in vitro study: twisted stainless steel and ceramic drills
Clin. Oral Impl. Res. 23 , 2012; 963–969
doi: 10.1111/j.1600‐0501.2011.02248.x     

Clinical results of alveolar ridge augmentation with mandibular block bone grafts in partially edentulous patients prior to implant placement

A group of 15 partially edentulous patients who needed alveolar ridge augmentation for implant placement, were consecutively treated using a two-stage technique in an outpatient environment. A total of 18 alveolar segments were grafted. During the first operation bone blocks harvested from the mandibular ramus or symphysis were placed as lateral or vertical onlay grafts and fixed with titanium osteosynthesis screws after exposure of the deficient alveolar ridge. After 6 months of healing the flap was re-opened, the screws were removed and the implants placed. Twelve months after the first operation implant-supported fixed bridges could be provided to the patients. Mean lateral augmentation obtained at the time of bone grafting was 6.5 +/- 0.33 mm, that reduced during healing because of graft resorption to a mean of 5.0 +/- 0.23 mm. Mean vertical augmentation obtained in the 9 sites where it was needed was 3.4 +/- 0.66 mm at bone grafting and 2.2 +/- 0.66 mm at implant placement. Mean lateral and vertical augmentation decreased by 23.5% and 42%, respectively, during bone graft healing (before implant insertion). Mandibular sites showed a larger amount of bone graft resorption than maxillary sites. All the 40 implants placed were integrated at the abutment connection and after prosthetic loading (mean follow-up was 12 months). No major complications were recorded at donor or recipient sites. Soft tissue healing was uneventful, and pain and swelling were comparable to usual dentoalveolar procedures. A visible ecchymosis was present for 4 to 7 days when the bone was harvested from the mandibular symphysis. From a clinical point of view this procedure appears to be simple, safe and effective for treating localised alveolar ridge defects in partially edentulous patients.