Outcomes of in-vitro fertilization after bariatric surgery: a national register-based case-control study.

STUDY QUESTION: Does previous bariatric surgery (BS) in women affect cumulative live birth rate in IVF? SUMMARY ANSWER: Women having had BS seem to have the same cumulative live birth rate as non-operated women of the same BMI at IVF treatment. WHAT IS KNOWN ALREADY: Because of the perinatal risks of obesity to mother and infant as well as impaired outcomes of IVF, obese women are advised to reduce their weight, but it is not clear whether previous BS could affect IVF results. STUDY DESIGN, SIZE, DURATION: This national register-based case-control study included all cases of BS (n = 30 436) undergoing IVF (n = 153) from 2007 until 2017. PARTICIPANTS/MATERIALS, SETTING, METHODS: Swedish women between 18 and 45 years operated with BS, with at least one first started cycle of IVF after surgery, were included. For each woman having IVF after BS (n = 153), up to five non-operated control women (n = 744) starting their first IVF cycle during the study period were matched for age, parity and BMI at treatment. The primary outcome in this study was the cumulative live birth rate (CLBR) after the first IVF cycle, defined as all live births after the first cycle including fresh and frozen embryo transfers. MAIN RESULTS AND THE ROLE OF CHANCE: There was no significant difference in CLBR between the BS group and the matched controls (29.4% compared to 33.1%), even though the number of retrieved oocytes (7.6 vs 8.9, P = 0.005) and frozen embryos (1.0 vs 1.5, P = 0.041) were significantly fewer in the BS group. There was no association between cumulative live birth and BS, adjusted odds ratio 1.04, 95% CI (0.73, 1.51). However, the birth weight was significantly lower in the children born to mothers with previous BS, mean (SD) 3190 (690) vs 3478 (729) g, P = 0.037. LIMITATIONS, REASONS FOR CAUTION: Confounders such as age, BMI and previous childbirth were accounted for by the matching design of the study, but there were no data on indication for IVF, anti-Müllerian hormone, smoking or previous comorbidities. The study was exploratory and did not reach sufficient power to detect potential smaller differences in live birth rates. WIDER IMPLICATIONS OF THE FINDINGS: The findings concur with those in previously published smaller studies and provide somewhat reassuring results considering IVF outcomes after BS with a CLBR comparable to that of controls, despite a lower mean birth weight. STUDY FUNDING/COMPETING INTEREST(S): This research was funded by grants from the Southern Health Care Region of Sweden. The authors have no competing interests to declare. TRIAL REGISTRATION NUMBER: N/A.

Impact of diet and bariatric surgery on anti-Müllerian hormone levels.

STUDY QUESTION: Do serum levels of anti-Müllerian hormone (AMH) change in women of reproductive age following dietary and surgery-induced weight loss? SUMMARY ANSWER: AMH levels increased after very low-calorie diet (VLCD) before surgery and decreased at 6 and 12 months after Roux-en-Y gastric bypass (RYGB), beyond expected normal age-related decline. WHAT IS KNOWN ALREADY: Obesity has negative effects on fertility and IVF outcomes, and possibly also on AMH levels. AMH correlates to the number of growing follicles and is used to predict the response to IVF treatment. However, AMH might decrease after bariatric surgery. STUDY DESIGN, SIZE, DURATION: A prospective cohort study of 48 women followed first for 8 weeks preoperatively, then operated with RYGB and followed postoperatively for 1 additional year. PARTICIPANTS/MATERIALS, SETTING, METHODS: Women aged 18-35 years with a mean (SD) BMI 40.9 (3.6) kg/m2 were included at baseline (BL). After the VLCD, a RYGB was performed. Body weight and height were measured at BL and 1 year postoperatively. Hormones were analysed at BL, after VLCD on the day before surgery, and at 6 and 12 months postoperatively. MAIN RESULTS AND THE ROLE OF CHANCE: Median AMH levels were 30.0 pmol/L at BL and rose significantly after VLCD (median: 35.0 pmol/L; P = 0.014). Median AMH at 6 and 12 months postoperatively were significantly lower (19.5 and 18.0 pmol/L, respectively; P = 0.001). Free androgen index (FAI) was significantly lower after 12 months, compared to BL (1.2 vs 3.5, P < 0.0005). LIMITATIONS REASONS FOR CAUTION: Ultrasound for PCOS diagnosis was not performed. The change in laboratory methods for AMH analysis during the study might be a limitation. WIDER IMPLICATIONS OF THE FINDINGS: Obese young women might choose bariatric surgery also for fertility reasons, and the observed decrease in FAI is in line with improved fertility. More research is needed to evaluate the clinical effects of the decrease of AMH, and the effect of bariatric surgery prior to IVF treatment. STUDY FUNDING/COMPETING INTEREST(S): Study-specific laboratory analyses were funded by the Swedish Regional Research Fund (ALF). Authors declare no competing interests. TRIAL REGISTRATION NUMBER: N/A.

Bacterial profiles and proteolytic activity in peri-implantitis versus healthy sites.

Peri-implantitis is a biofilm-induced destructive inflammatory process that, over time, results in loss of supporting bone around an osseointegrated dental implant. Biofilms at peri-implantitis sites have been reported to be dominated by Gram-negative anaerobic rods with a proteolytic metabolism such as, Fusobacterium, Porphyromonas, Prevotella and Tannerella, as well as anaerobic Gram-positive cocci. In this study, we hypothesized that protease activity is instrumental in driving bone destruction and we therefore compared the microbial composition and level of protease activity in samples of peri-implant biofluid (PIBF) from 25 healthy subjects (H group) and 25 subjects with peri-implantitis (PI group). Microbial composition was investigated using culture techniques and protease activity was determined using a FITC-labelled casein substrate. The microbial composition was highly variable in subjects both in the H and PI groups but one prominent difference was the prevalence of Porphyromonas/Prevotella and anaerobic Gram positive cocci which was significantly higher in the PI than in the H group. A subgroup of subjects with peri-implantitis displayed a high level of protease activity in the PIBF compared to healthy subjects. However, this activity could not be related to the presence of specific bacterial species. We propose that a high level of protease activity may be a predictive factor for disease progression in peri-implantitis. Further longitudinal studies are however required to determine whether assessment of protease activity could serve as a useful method to identify patients at risk for progressive tissue destruction.

Sperm DNA integrity in cancer patients: the effect of disease and treatment.

As oncological treatment might impair the patients' fertility, male cancer patients are offered to cryopreserve semen prior to treatment. Impaired sperm DNA quality is associated with reduced fertility, and in case of assisted reproduction, sperm DNA integrity may have an impact on choice of method. Therefore, we have assessed sperm DNA integrity in cancer patients, comparing pre- and post-treatment quality. Sperm DNA integrity was investigated in cryopreserved semen from 121 cancer patients, the predominating diagnoses were germ cell cancer (GCC) and Hodgkin's lymphoma (HL). Post-treatment samples, with a median follow-up of 3 years, were analysed for 58 of the men, allowing a pre- and post-treatment analysis on an individual basis. Sperm DNA integrity was assessed using the Sperm Chromatin Structure Assay and expressed here as the DNA Fragmentation Index (DFI%). One hundred and thirty-seven fertile men served as controls. Before treatment, GCC (n = 84) and HL (n = 18) patients had higher DFI% than controls (n = 143) with a mean difference of 7.7 (95% CI 3.2-8.8) and 7.0 (95% CI 2-12), respectively. The same trend was observed for other cancer diagnoses, but without reaching statistical significance (mean difference 3.6, 95% CI -1.2 to 8.4). No increase was seen in DFI% comparing pre- and post-treatment semen, regardless of treatment modality. A moderate elevation of DFI% was observed in cryopreserved semen from cancer patients. Oncological treatment, generally, did not induce any increase in DFI. These findings should be considered when discussing the utilization of pre-treatment cryopreserved semen vs. post-treatment fresh sperm in cancer patients undergoing assisted reproduction.

Aerobiology in the operating room and its implications for working standards.

Two novel operating room (OR) ventilation concepts, i.e. the upward displacement or thermal convection system and the exponential ultra-clean laminar air flow (LAF) designed to function without extra walls, were evaluated from a bacteriological point of view. The thermal convection system (17 air changes/h) was compared with conventional ventilation (16 air changes/h) with an air inlet at the ceiling and evacuation at floor level. The exponential LAF was compared with the vertical ultra-clean LAF and the horizontal ultra-clean LAF, both with extra side walls. The comparison was made using strictly standardized simulated operations and, except for the horizontal LAF, it was performed in the same OR where the type of ventilation was changed. In the different areas important for surgical asepsis, the thermal system resulted in a twofold to threefold increase in bacterial air and surface counts compared to the conventional system (statistical significance = p < 0.05-0.0001). The bacteriological efficiency of the exponential LAF was equal to the horizontal and vertical LAF units with extra walls in the OR, and all three systems easily fulfilled the criteria for ultra-clean air, i.e. bacteria-carrying particles < 10/m3. In the areas important for surgical asepsis the turbulent ventilation systems yielded highly significant correlation between air and surface contamination (p < 0.02-0.0006). No such correlation existed in the LAF systems.

Radiation treatment of epidermoid cancer of the anus.

PURPOSE: The purpose of this study was to evaluate our treatment results of anal cancer. METHODS AND MATERIALS: During the years 1985-1990, 82 patients with invasive epidermoid and cancer were referred to the Department of Oncology at Södersjukhuset. In 76 cases irradiation was used in the primary therapy, and in 43 cases bleomycin was administered concurrently. Fifteen of these tumors were situated in the perianus and 61 in the anal canal. Probability of survival, recurrence, and preservation of anal sphincter was analyzed according to Kaplan-Meier. Cox multivariate analysis was used in studying potential determinants of risk for treatment failure. RESULTS: Tumor-specific survival at 5 years was 71% for both anal canal and perianal cancer. Analyses with regard to cancer of the anal canal indicated that T4 tumors had significantly worse prognosis than those in stages T1-3. Overall survival was 73% and 79% at 5 years for T1 and T2 tumors and 73% and 18% at 4 years for T3 and T4 tumors. Corresponding figures for tumor specific survival were 79%, 79%, 82%, and 31%. Eighty-five percent of patients with T1 tumors, had a preserved anal sphincter after 4 years. For T2 and T3 tumors the corresponding figures were 62% and 60%. Also the multivariate analyses showed stage T4 to be a strong negative prognostic determinant. There was no firm evidence of a positive effect of bleomycin on the treatment results, but it increased the acute radiation toxicity. CONCLUSION: Primary radiotherapy of anal cancer yielded a high probability of survival, but in many cases sphincter amputation have been necessary. The role of bleomycin appears questionable.

Induction chemotherapy and radiotherapy in loco-regionally advanced epidermoid carcinoma of the anal canal.

PURPOSE: To evaluate the efficacy of induction chemotherapy in combination with radiotherapy for treatment of loco-regionally advanced epidermoid anal carcinoma. METHODS AND MATERIALS: Thirty-one patients diagnosed during the period 1989-1994 with loco-regionally advanced cancer of the anal canal (phiTmax > or = 4 cm or T4 or N+) were treated with induction chemotherapy consisting of one to three courses of carboplatin (300-375 mg/m2 i.v.) and 5-fluorouracil [5,000 mg/(m2 x 120 h) i.v.] followed by external beam irradiation +/- surgery. RESULTS: The toxicity of the chemotherapy was low. Twenty-nine patients were tumor free after the primary therapy. Kaplan-Meier analyses were made for overall survival, tumor-specific survival, freedom from recurrence, preservation of sphincter, and event-free survival. For these end points the 5-year data were 67, 85, 80, 69, and 51%, respectively. CONCLUSION: The results are promising but a well-designed randomized trial is needed to further elucidate the role of induction chemotherapy in the treatment of loco-regionally advanced anal carcinoma.

The addition of a mobile ultra-clean exponential laminar airflow screen to conventional operating room ventilation reduces bacterial contamination to operating box levels.

A mobile screen producing ultra-clean exponential laminar airflow (LAF) was investigated as an addition to conventional turbulent/mixing operating room (OR) ventilation (16 air changes/h). The evaluation was performed in a small OR (50 m(3)) during 60 standardized operations for groin hernia including mesh implantation. The additional ventilation was used in 50 of the operations. The LAF passed from the foot-end of the OR table over the instrument and surgical area. Strict hygiene OR procedures including tightly woven and non-woven OR clothing were used. Sedimentation rates were recorded at the level of the patients' chests (N=60) (i.e. the air had passed the surgical team) and in the periphery of the OR. In addition bacterial air contamination was studied above the patients' chests in all 10 operations without the additional LAF and in 12 with the LAF. The screen reduced the mean counts of sedimenting bacteria (cfu/m(2)/h) on the patients' chests from 775 without the screen to 355 (P=0.0003). The screen also reduced the mean air counts of bacteria (cfu/m(3)) above the patients' chests from 27 to 9 (P=0.0001). No significant differences in mean sedimentation rates (cfu/m(2)/h) existed in the periphery of the OR where 628 without and 574 with screen were recorded. During the follow-up period of six months no surgical site infections were detected. In conclusion when the mobile LAF screen was added to conventional OR ventilation the counts of aerobic airborne and sedimenting bacteria-carrying particles downstream of the surgical team were reduced to the levels achieved with complete ultra-clean LAF OR ventilation (operating box).

Inconsistent correlation between aerobic bacterial surface and air counts in operating rooms with ultra clean laminar air flows: proposal of a new bacteriological standard for surface contamination.

The relationship between surface contamination (cfus/m2/h) with particles carrying aerobic bacteria and corresponding air contamination rates (cfus/m3) was evaluated in operating rooms (OR) equipped with ultra clean vertical or horizontal laminar airflow (LAF). For the evaluation we collected data during strictly standardized sham operations using non-woven disposable or cotton clothing. Air contamination in the wound and instrument areas (Casella slit sampler) was related to the surface contamination rate (settle plates) in the same areas and in addition, on the patient chest. Typically, the mean surface counts were 20-70 cfus/m2/h and the air counts 1-2 cfus/m3 in disposable clothing experiments, whilst the use of cotton clothing resulted in higher counts of 100-200 cfus/m2/h (wound P > 0.05, patient P > 0.05, instruments P < 0.01) and 4 cfus/m3 (P < 0.02-0.001). In the vertical LAF, taking both disposable and cotton clothing operations together, the surface and air contamination rates (surface/air ratio SAR) were highly correlated (P = 0.02-0.004) and the ratio varied between 18:1 and 50:1 with a mean for wound air of 36:1. Using only disposable clothing in the vertical LAF, the number of significant correlations was reduced. With cotton clothing experiments in vertical LAF and in the horizontal LAF using disposable clothing, no significant correlation between surface and air contamination was found. The wide variation of SAR values and the inconsistent relationship between surface and air counts indicates that measurement of OR air contamination represents an unhelpful method for assessment of surgical site contamination in LAF units. We propose instead that colony counts on sedimentation plates is a clinically more relevant indicator of bacterial OR contamination in LAF units. In addition to the current bacteriological standard for ultra clean OR air of (< 10 cfus/m3) we suggest a corresponding standard for the surface contamination rate of < 350 cfus/m2/h.

Correlation between surface and air counts of particles carrying aerobic bacteria in operating rooms with turbulent ventilation: an experimental study.

Airborne contamination with bacteria-carrying particles (cfu/m3) and their sedimentation rate (cfu/m2/h) was compared in an operating room (OR) equipped with two turbulent ventilation systems. One was a thermally based system with inlet of cool clean air at the floor level and evacuation of the air at the ceiling by convection (17 air changes/h). The other was a conventional plenum pressure system with air supply at the ceiling and evacuation at the floor level (16 air changes/h). The study was made during rigidly standardised sham operations (N = 20) performed in the same OR by the same six member team wearing non-woven disposable or cotton clothing. Airborne contamination in the wound and instrument areas was related to the surface contamination rate in the same areas and in addition, on the patient chest and in the periphery of the OR. With the exception of the periphery of the OR, the surface and air contamination rates were highly correlated in both ventilation systems (P = 0.02-0.0006, r2 = 0.52-0.79). This was also true particularly when disposable clothing was used while the correlation was weaker in cotton clothing experiments. An equation describing the relation between surface and air counts is given. Typically, the surface counts were numerically 16-fold the air counts, i.e., the number of colonies sedimenting on four 14 cm-diameter agar plates during 1 h will almost equal the number of airborne cfu per m3. We propose, that sedimentation plates represent not only a technically easier method than air sampling but when correctly used, are also the most realistic indicator of airborne bacterial OR contamination in areas critical for surgery.

Mobile zoned/exponential LAF screen: a new concept in ultra-clean air technology for additional operating room ventilation.

A mobile screen (0.5 x 0.4 m) producing ultra-clean exponential LAF (air-flow central zone 0.6 m/s and peripheral zone 0.4 m/s) was investigated as an addition to conventional turbulent/mixing operating room ventilation. The evaluation was performed during strictly standardized sham operations reflecting conditions during major surgery. The study consisted of a pilot experiment designed to give high counts of sedimenting aerobic colony forming units (cfu). In a second main study, recording dust particles, air-borne and sedimenting aerobic cfu, the screen was associated with optimal operating room clothing. In the pilot experiment the use of the screen resulted in a substantial reduction of sedimenting bacteria from 3835-4940 to 0-390 cfu/m(2)/h. In the main study, the use of the additional LAF reduced the surface contamination from 416-329 to 7-78 cfu/m(2)/h up to 1.6 m from the screen (P=0.001-0.0001). Measured in the wound area the screen reduced the air counts of bacteria from 9-14 to 0.2-0.4 cfu/m(3) (P=0.008-0.0001) and a marked reduction of air-borne dust particles was recorded (P=0.007-0.009). In conclusion, the additional mobile LAF screen reduced the counts of aerobic air-borne and sedimenting bacteria-carrying particles as well as dust particles to the levels gained with complete ultra-clean LAF room ventilation. Thus, the screen might prove a valuable addition to operating room ventilation as well as in other areas where asepsis is essential.

Surgical area contamination--comparable bacterial counts using disposable head and mask and helmet aspirator system, but dramatic increase upon omission of head-gear: an experimental study in horizontal laminar air-flow.

The effect of different head coverings on air-borne transmission of bacteria and particles in the surgical area was studied during 30 strictly standardized sham operations performed in a horizontal laminar air flow (LAF) unit. The operating team members wore disposable gowns plus either a non-sterile head covering consisting of a squire type disposable hood and triple laminar face mask, a sterilized helmet aspirator system or no head cover at all. In the wound area both types of head cover resulted in low and comparable air (means of 8 and 4cfu/m(3)) and surface contamination (means of 69 and 126cfu/m(2)/h) rates. Omission of head-gear resulted in a three- to five-fold increase (P > or = 0.01- 0.001), depending on site sampled air contamination rate (mean of 22cfu/m(3)) whereas the bacterial sedimentation rate in the wound area increased about 60-fold ( P > or = 0.0001). A proper head cover minimized the emission of apparently heavy particles that were not removed by the horizontal LAF and contained mainly streptococci, presumably of respiratory tract origin. Dust particle counts revealed no differences between the three experimental situations. No correlation between air and surface contamination rates or between air contamination and air particle counts was found. We conclude that, from a bacteriological point of view, disposable hoods of squire type and face masks are equally as efficient as a helmet aspirator system and both will efficiently contain the substantial emission of bacteria-carrying droplets from the respiratory tract occurring when head cover is omitted. Finally, the use of bacterial air counts to assess surgical site surface contamination in horizontal LAF units must be seriously questioned.

Inefficiency of upward displacement operating theatre ventilation.

A new thermally based ventilation system ('Floormaster') with inlet of cool clean air at floor level, and evacuation at the ceiling of the air warmed by activity in the room (upward displacement ventilation, 17 air changes/h) was compared with a standard positive pressure (plenum) ventilation system with air supply through an inclined perforated screen along one wall at the ceiling and evacuation at floor level (conventional turbulent or mixing system, 16 air changes/h). The study was made during rigidly standardized sham operations (N = 20) performed in the same operating room by a six-member team wearing non-woven disposable or cotton clothing. In general the upward displacement system removed dust particles too small to carry bacteria (0.16-<0.3 microm, 0.001

Salivary kallikrein in Sjögren's syndrome.

Using a chromogenic substrate (H-D-Val-Leu-Arg-pNA) salivary kallikrein levels were measured in whole saliva samples from patients suffering from Sjögren's syndrome (SS). Compared to healthy control individuals, SS patients, especially those without corticosteroid medication, exhibited significantly elevated kallikrein levels. A diurnal variation was found with the highest kallikrein activities in morning saliva. No correlation between kallikrein levels and extension of the inflammation in labial salivary glands (focus score), salivary flow rates or diagnosis (primary versus secondary SS) could be observed. A pathogenic mechanism for kallikrein in autoimmune sialadenitis is discussed.

Thermal conductivity of uterine tissue in vitro.

Thermotherapy of the uterus has emerged as an alternative to hysterectomy in the treatment of menorrhagia, from whence it follows that the thermal properties of uterine tissue have become of importance. This study presents measurements of the thermal conductivity and the water content of uterine tissue in vitro. A steady-state thermal conductivity apparatus, based on the comparison of test samples with a material with known thermal conductivity, is described. Measurements were conducted on tissue samples from eleven patients, directly after hysterectomy. Samples with and without endometrium, as well as coagulated samples, were examined. The thermal conductivity of myometrial tissue was found to be 0.536 +/- 0.012 W m(-1) K(-1) (mean +/- 1 SD) and the corresponding water content was 81.2 +/- 1.5% (mean +/- 1 SD). Measurements on samples with both endometrium and myometrium showed similar thermal conductivity (0.542 +/- 0.008 W m(-1) K(-1), mean +/- 1 SD) and water content (81.6 +/- 0.7%, mean +/- 1 SD). It was also indicated that coagulation causes dehydration, resulting in a lower thermal conductivity.

Brånemark implants and osteoporosis: a clinical exploratory study.

BACKGROUND: Oral implant treatment on patients with poor jaw-bone texture has shown increased failure rates in series of studies. PURPOSE: The purpose of the present study was to retrospectively follow patients with osteoporosis of the axial or appendicular skeleton, including the jaw bone, being subjected to oral implant treatment. The outcome of inserted implants, when using an adapted bone site preparation technique and extended healing periods, was evaluated. MATERIALS AND METHODS: Based on data obtained from preoperative radiographs, patient medical history, and resistance of the jaw bone perceived during drilling, 14 of 16 patients were referred to the Osteoporosis Laboratory, Sahlgren University Hospital, Göteborg, Sweden, for bone density measurements. Two patients already had an established diagnosis of osteoporosis. Fourteen jaws in 13 patients (11 females, 2 males; mean age: 68 yr) were subsequently subjected to oral implant treatment with a total of 70 implants (Brånemark System) of various designs. The mean follow-up period was 3 years and 4 months (range: 6 mo-11 yr). RESULTS: Osteoporosis of either the spine, the hip, or both regions was diagnosed in 14 patients, and osteopenia was diagnosed in 2 patients. Two implants failed, and the overall implant survival rate at the end of the study period was 97.0% for maxillae and 97.3% for mandibles. The marginal bone resorption at the 1-year follow-up concurs with the outcome of other studies, irrespective of the preoperative bone texture present. CONCLUSION: The outcome of the present study showed that implant placement in patients in whom the average bone density showed osteoporosis in both lumbar spine and hip as well as poor local bone texture may be successful over a period of many years.

Long-term follow-up of severely atrophic edentulous mandibles reconstructed with short Brånemark implants.

BACKGROUND: Oral implant treatment (Brånemark System) of edentulous mandibles has been presented in numerous studies. However, with regard to the severely atrophic lower jaw, no long-term follow-up studies with solely short implants are available. PURPOSE: The purpose of the present investigation was to retrospectively follow the long-term treatment outcome of patients with severely resorbed edentulous mandibles being subjected to oral implant placement with short (6-7 mm) Brånemark implants. MATERIALS AND METHODS: A total of 247 standard (7 mm long, Ø 3.75 mm) and 13 wide (6 mm long, Ø 5 mm) implants were inserted in 49 patients, all of whom exhibited severe resorption of edentate mandibles. Fixed implant-supported prostheses were manufactured for 45 patients, whereas 4 patients received overdentures. The patients were followed for a mean period of 8 years (range, 1-14 yr). RESULTS: Seventeen implants failed during the study period (cumulative implant survival rate 95.5% at 5-yr and 92.3% at 10-yr follow-up). Implant-supported constructions were worn continuously throughout the investigation by all study subjects. Marginal bone loss, measured after 1, 5, and 10 years of function, concurred with studies of Brånemark implants placed in more voluminous mandibles. No major clinical or construction complications occurred in the followed patients. CONCLUSIONS: The outcome of the present study showed that placement of short Brånemark implants without the use of bone grafting procedures for reconstruction of severely atrophic edentulous mandibles is a highly predictable treatment procedure.

On cutting torque measurements during implant placement: a 3-year clinical prospective study.

BACKGROUND: Evaluation of jaw bone quality at implant placement is mainly based on preoperative radiographic assessments and subjective hand registrations during implant site preparation. An objective technique with cutting torque measurements has been introduced, presenting an objective bone quality or bone hardness value of individual implant sites. PURPOSE: The purpose of this study was to evaluate cutting torque measurements during implant placement and to compare these values in different regions in mandibles and maxillae. The objective was to identify implants at risk for failing at implant placement. MATERIAL AND METHODS: Cutting torque measurements were performed during placement of Mk II self-tapping implants (Brånemark System) in 105 patients, comprising 72 edentulous (40 maxillae) and 34 partially edentulous (22 maxillae) jaws. A total of 523 implants were inserted, of which 420 were of the Mk II design and of which 412 were subjected to cutting torque measurements. Statistical analyses were performed by comparing cutting torque values of maxillae and mandibles and of different jaw regions. Cutting torque values were also correlated with radiographically and clinically assessed bone quality scores. Patients were followed clinically for a minimum of 3 years. RESULTS: A statistically significant difference in cutting torque values of maxillae and mandibles was seen, although not when comparing anterior and posterior regions within the same jaws or of different jaws. Significant correlations were found between values of cutting torque and bone quality. The majority of failures were seen in bone of medium to high density, whereas implants inserted in bone of poor density presented a better outcome, perhaps due to an adapted surgical protocol and an extended healing period. The overall implant survival rate at 3 years was 95%, and when analyzing different jaw categories, survival rates of 92.0% and 99.4% were seen for edentulous maxillae and mandibles, respectively. The corresponding figures for partially edentulous jaws were 95.4% and 97.6%. CONCLUSION: It was not possible to identify sites at risk for future implant losses or to determine a lower limit value of cutting torque in order to achieve successful implant integration.

Early failures in 4,641 consecutively placed Brånemark dental implants: a study from stage 1 surgery to the connection of completed prostheses.

This study comprised 4,641 Brånemark dental implants, which were retrospectively followed from stage 1 surgery to completion of the prosthetic restorations. The implants were placed during a 3-year period (1986 to 1988) in 943 jaws, representing 889 patients with complete and partial edentulism. The jaw and sex distribution revealed a predominance of mandibles (564/943) and females (534/943). The mean age of the patients was 57.5 years (range 13 to 88 years) at implant placement. Only 69 (1.5%) fixtures failed to integrate, and most losses were seen in completely edentulous maxillae (46/69), in which the jaw bone exhibited soft quality and severe resorption. A preponderance of failures could also be seen among the shortest fixtures (7 mm). A majority of the mobile implants were recorded at the abutment connection (stage 2) operation (48/69).

A new self-tapping Brånemark implant: clinical and radiographic evaluation.

A new self-tapping Brånemark implant designed for denser bone qualities was evaluated with regard to insertion technique, complications, marginal bone remodeling, and survival rate. Thirty patients, representing 21 mandibles and 9 maxillae, participated in the study. In each patient both standard and self-tapping implants were placed, and a total of 179 implants, 88 self-tapping and 91 standard, were inserted. Thirteen of 62 mandibular self-tapping implants reached their correct positions only after using the screw tap or the cylinder wrench for manual insertion. No such problems were noted when using standard fixtures after bone pre-tapping. In the maxillae, neither of the two implant designs presented any problems. One standard and one self-tapping fixture failed to osseointegrate. Radiolucencies were seen in the bone around the apical portion of two fixtures, one of each design. The mean marginal bone resorption after 1 year of follow-up was 0.5 to 0.6 mm for the two fixture types.