Carprofen neither reduces postoperative facial expression scores in rabbits treated with buprenorphine nor alters long term bone formation after maxillary sinus grafting

In connection with bilateral maxillary sinus augmentation, the acute effects of the nonsteroidal anti-inflammatory drug carprofen on facial expressions and long-term effects on bone formation were evaluated in 18 male New Zealand White rabbits. A 10 × 10mm bone window was drilled in the maxilla, the sinus membrane elevated and a titanium mini-implant inserted. One of two test materials was randomly inserted unilaterally and bovine bone chips (control) on the contralateral side in the created space. Rabbits were randomly allocated to receive buprenorphine plus carprofen (n = 9) or buprenorphine plus saline (n = 9) postoperatively. Buprenorphine was administered subcutaneously every 6 h for 3 days in a tapered dose (0.05-0.01 mg/kg) and carprofen (5 mg/kg) or saline administered subcutaneously 1 h before, and daily for 4 days postoperatively. To assess pain, clinical examination, body weight recording and scoring of facial expressions from photos taken before, and 6-13 h after surgery were performed. Twelve weeks after surgery the rabbits were euthanized and sections of maxillary bones and sinuses were analysed with histomorphometry and by qualitative histology. Carprofen had no effect on mean facial expression scores,which increased from 0.0 to 3.6 (carprofen) and 4.3 (saline), of a maximum of 8.0. Neither did carprofen have an effect on bone formation or implant incorporation, whereas the test materials had. In conclusion, treatment with 5mg/kg carprofen once daily for 5 days did not reduce facial expression scores after maxillary sinus augmentation in buprenorphine treated rabbits and did not affect long term bone formation

Clinical and experimental studies of bone substitutes and dental implants in compromised bone sites

Background: With an ageing population, an increase of more challenging implant treatments is expected. In this thesis, we evaluate the outcome of two faster implant protocols, in patients with compromised alveolar bone. We examine the bone integrating abilities of two new synthetic bone substitute materials and in another paper, we discuss the effects of nonsteroidal anti-inflammatory drugs (NSAID) on bone healing. Aim: In paper I we investigate implant survival and effect of reduced implant-tooth distance. In paper II we evaluate the long-term implant survival and function of immediately loaded implants. In paper III & IV, we analyse if added NSAID reduce postoperative pain and if it has a reduced effect on new bone formation in a rabbit sinus lift model. We also investigate if a ceramic compound (CPC, granules) and hydrogel (HABP.CaP) result in a similar or larger bone amount, in comparison with bovine bone mineral. In Paper V we assess new bone formation adjacent to a hollow CPC implant. Material & Methods: Paper I present a clinical and radiological follow-up, performed on subjects that previously received 3.0-3.3 mm diameter implants in the aesthetic area. In paper II, clinical and radiographic examinations were performed on subjects that had received six implants each with immediate loading in the maxilla 8-11-year ago. For paper III-IV, pain was assessed by clinical examination and scoring of facial expressions from photos. Histomorphometry and histology evaluations were performed. In paper V, a critical radius defect was created and either replaced by particulate autologous bone (AB) or a CPC implant. Qualitative and quantitative radiographic and histology evaluations were performed.  Results: In paper I, an implant survival of 97.2% up to 124 months was shown with a tooth-implant distance in many cases of  <1.5 mm. Discoloration and recession of the buccal gingiva was the most frequent patient concern. In paper II a cumulative implant survival rate was 81.9 % at the final follow-up. In paper III and IV it was shown that NSAID had no effect on pain relief or bone formation. No difference was shown between CPC and control, but both showed larger bone amount and BIC than HABP.CaP. In paper V new bone was seen in sites throughout the entire CPC implant. Conclusion: Satisfactory long-term dental implant results can be obtained without bone augmentation in most patients with atrophic alveolar bone, but there is still a minority in this group that may benefit of bone enhancement prior to implant treatment. To avoid the negative effects of autologous bone grafting, synthetic materials as the presented CPC, have shown promising results as a solution or alternative to existing bone substitutes in animal models

Clinical and experimental studies of bone substitutes and dental implants in compromised bone sites

Background: With an ageing population, an increase of more challenging implant treatments is expected. In this thesis, we evaluate the outcome of two faster implant protocols, in patients with compromised alveolar bone. We examine the bone integrating abilities of two new synthetic bone substitute materials and in another paper, we discuss the effects of nonsteroidal anti-inflammatory drugs (NSAID) on bone healing. Aim: In paper I we investigate implant survival and effect of reduced implant-tooth distance. In paper II we evaluate the long-term implant survival and function of immediately loaded implants. In paper III & IV, we analyse if added NSAID reduce postoperative pain and if it has a reduced effect on new bone formation in a rabbit sinus lift model. We also investigate if a ceramic compound (CPC, granules) and hydrogel (HABP.CaP) result in a similar or larger bone amount, in comparison with bovine bone mineral. In Paper V we assess new bone formation adjacent to a hollow CPC implant. Material & Methods: Paper I present a clinical and radiological follow-up, performed on subjects that previously received 3.0-3.3 mm diameter implants in the aesthetic area. In paper II, clinical and radiographic examinations were performed on subjects that had received six implants each with immediate loading in the maxilla 8-11-year ago. For paper III-IV, pain was assessed by clinical examination and scoring of facial expressions from photos. Histomorphometry and histology evaluations were performed. In paper V, a critical radius defect was created and either replaced by particulate autologous bone (AB) or a CPC implant. Qualitative and quantitative radiographic and histology evaluations were performed.  Results: In paper I, an implant survival of 97.2% up to 124 months was shown with a tooth-implant distance in many cases of  <1.5 mm. Discoloration and recession of the buccal gingiva was the most frequent patient concern. In paper II a cumulative implant survival rate was 81.9 % at the final follow-up. In paper III and IV it was shown that NSAID had no effect on pain relief or bone formation. No difference was shown between CPC and control, but both showed larger bone amount and BIC than HABP.CaP. In paper V new bone was seen in sites throughout the entire CPC implant. Conclusion: Satisfactory long-term dental implant results can be obtained without bone augmentation in most patients with atrophic alveolar bone, but there is still a minority in this group that may benefit of bone enhancement prior to implant treatment. To avoid the negative effects of autologous bone grafting, synthetic materials as the presented CPC, have shown promising results as a solution or alternative to existing bone substitutes in animal models

Clinical and experimental studies of bone substitutes and dental implants in compromised bone sites

Background: With an ageing population, an increase of more challenging implant treatments is expected. In this thesis, we evaluate the outcome of two faster implant protocols, in patients with compromised alveolar bone. We examine the bone integrating abilities of two new synthetic bone substitute materials and in another paper, we discuss the effects of nonsteroidal anti-inflammatory drugs (NSAID) on bone healing. Aim: In paper I we investigate implant survival and effect of reduced implant-tooth distance. In paper II we evaluate the long-term implant survival and function of immediately loaded implants. In paper III & IV, we analyse if added NSAID reduce postoperative pain and if it has a reduced effect on new bone formation in a rabbit sinus lift model. We also investigate if a ceramic compound (CPC, granules) and hydrogel (HABP.CaP) result in a similar or larger bone amount, in comparison with bovine bone mineral. In Paper V we assess new bone formation adjacent to a hollow CPC implant. Material & Methods: Paper I present a clinical and radiological follow-up, performed on subjects that previously received 3.0-3.3 mm diameter implants in the aesthetic area. In paper II, clinical and radiographic examinations were performed on subjects that had received six implants each with immediate loading in the maxilla 8-11-year ago. For paper III-IV, pain was assessed by clinical examination and scoring of facial expressions from photos. Histomorphometry and histology evaluations were performed. In paper V, a critical radius defect was created and either replaced by particulate autologous bone (AB) or a CPC implant. Qualitative and quantitative radiographic and histology evaluations were performed.  Results: In paper I, an implant survival of 97.2% up to 124 months was shown with a tooth-implant distance in many cases of  <1.5 mm. Discoloration and recession of the buccal gingiva was the most frequent patient concern. In paper II a cumulative implant survival rate was 81.9 % at the final follow-up. In paper III and IV it was shown that NSAID had no effect on pain relief or bone formation. No difference was shown between CPC and control, but both showed larger bone amount and BIC than HABP.CaP. In paper V new bone was seen in sites throughout the entire CPC implant. Conclusion: Satisfactory long-term dental implant results can be obtained without bone augmentation in most patients with atrophic alveolar bone, but there is still a minority in this group that may benefit of bone enhancement prior to implant treatment. To avoid the negative effects of autologous bone grafting, synthetic materials as the presented CPC, have shown promising results as a solution or alternative to existing bone substitutes in animal models

Guided bone tissue regeneration using a hollow calcium phosphate based implant in a critical size rabbit radius defect

Long bone fractures are common and sometimes difficult to treat. Autologous bone (AB), bovine bone and calcium phosphates are used to stimulate bone growth with varying results. In the present study, a calcium phosphate cement (CPC) that previously showed promising grafting capabilities was evaluated for the first time in a long bone defect. A radius defect of 20 mm was created in 20 rabbits. The defect was filled by either a hollow CPC implant that had been manufactured as a replica of a rabbit radius through indirect 3D printing, or by particulate AB as control. Defect filling and bone formation was evaluated after 12 weeks by combining micro computed tomography (mu CT) and scoring of 3D images, together with histomorphometry and histology. The mu CT and histomorphometric evaluations showed a similar amount of filling of the defect (combining graft and bone) between the CPC and AB group, but the scoring of 3D images showed that the filling in the CPC group was significantly larger. Histologically the AB graft could not be distinguished from the new bone. The AB treated defects were found to be composed of more bone than the CPC group, including reorganised cancellous and cortical bone. Both the CPC and AB material was associated with new bone formation, also in the middle of the defect, which could result in closing of the otherwise critically sized gap. This study shows the potential for an indirectly 3D printed implant in guided bone regeneration in critically sized long bone defects

The effect of housing environment on bone healing in a critical radius defect in New Zealand White rabbits.

In animal studies on bone healing, the effect of housing space and physical activity are seldom taken into account. Bone formation was evaluated in New Zealand White rabbits (mean ± SEM BW: 3.9 ± 0.11 kg) with a critical bone defect after 12 weeks of rehabilitation in pair-housing in 3 m2 large floor pens (Floor, n = 10) or standard single housing in 0.43 m2 cages (Cage, n = 10). In the randomised full-factorial study, a bone replica of calcium phosphate cement (CPC, n = 10) or autologous bone (AB, n = 10) was implanted in the unilateral 20 mm radius defect. Post-mortem, the oxidative capacity was measured by citrate synthase (CS) activity in M. quadriceps and the defect filling volume and density evaluated by microcomputer tomography (μ-CT). Histology sections were evaluated by subjective scoring and histomorphometry. Fourteen rabbits remained until the end of the study. Group Floor (n = 7; 3 CPC + 4 AB) had a higher CS activity and a larger bone defect filling volume and lower density by μ-CT measurements than group Cage (n = 7; 3 CPC + 4 AB). Three out of four rabbits in AB-Floor presented fusion of the defect with reorganisation of trabecular bone, whereas three of four in AB-Cage showed areas of incomplete healing. Floor rabbits had a higher score of bony fusion between the radius and ulna than Cage rabbits. There were no differences between groups in histomorphometry. The study found that a larger housing space increased physical activity and promoted bone formation