Longer Healing Period Research Articles

The Role of Leukocyte and Platelet-Rich Fibrin in Enhancing the Healing of Extraction Sockets: An Overview of the Literature

Introduction: Leukocyte and platelet-rich fibrin (L-PRF) is an emerging material in dentistry, however, there are controversies surrounding its effectiveness. Despite the amount of literature available, debates regarding its effect continue. This review aims to summarize and clarify the data surrounding the use of L-PRF in promoting the healing of extraction sockets, which may offer a better outcome for future treatments. Purpose: The purpose of this review is to evaluate the current literature on the use of L-PRF in promoting the healing of extraction sockets, and to provide a comprehensive overview of the available evidence. Methods: A comprehensive computer-based search of databases such as PubMed, Medline, and Cochrane Library was conducted. Results: The results of this review suggest that L-PRF has shown promise in promoting early healing of extraction sockets, but the evidence for its effectiveness over a longer period is limited. Conclusion: Although L-PRF has shown promising results in the early healing periods, its effectiveness over a longer healing period cannot be confirmed based on the available data. More clinical trials with standardized protocols and consistent measurement methods are needed to establish the role of L-PRF in enhancing the healing of extraction sockets.

A PROSPECTIVE OBSERVATIONAL STUDY ON SURGICAL INTERVENTION IN EARLY AND LATE CASES OF CARBUNCLE IN TYPE 2 DIABETES MELLITUS

BACKGROUND: carbuncle is aggregation of multiple furuncles that form an inammatory mass. This typically drains on skin surface via openings. Patient may present with sepsis that require antibiotics administration and drainage. Diabetic patients who present late are often in septic shock with organ dysfunction. Objectives:To evaluate differences on presentation,associated morbidity and mortality in diabetic patients with carbuncle who present early(<7days) and late(>7days). MATERIALS AND METHODS: Our study included all patients admitted in surgical wards of JJMMC, Davanagere. This randomized prospective study comprising 40 patients of carbuncle over a period of 2years. INCLUSION CRITERIA: Patients>18years, with conrmed and newly detected type 2 diabetes mellitus, acute or chronic lesions of carbuncle. EXCLUSION CRITERIA: Patient <18years of age, with carbuncle but non diabetic. RESULTS: The Mean size of carbuncle in Early and late group was 8.85 cm and13.45 cm respectively, signicantly larger in late group. Sepsis at presentation was seen in 4 patients in early and 11 in late group, with signicantly higher incidence in late group. DKAseen in 2 patients in early and 13 in late group, signicantly higher incidence in late group. The mean duration of hospital stay was 4.75 days in Early and 7.35 days in late group, with signicantly longer stay in Late Group. The mean period of healing was 5weeks in early and 7weeks in late group, with signicantly longer healing period in late Group.

Clinical Outcomes of Alveolar Ridge Augmentation with In Situ Autogenous Block Bone: A Retrospective Review.

To present clinical outcomes of alveolar ridge augmentation using in situ autogenous block bone and to compare the outcomes with previous studies. The medical records of patients with a severe horizontal bone defect in a partially edentulous alveolar ridge (width < 3.5 mm), who received bone augmentation using in situ autogenous block bone, were retrospectively reviewed. After a 6-month or longer healing period, the augmentation effect was examined before implant placement. Cone beam computed tomography (CBCT) was performed before and after surgeries. The alveolar width of the bone grafts was measured on the CBCT images. A total of 16 patients (22 grafts) were included. Graft exposure was seen in three grafts, which were classified as failed cases. The augmentation volume at implant placement in the failed cases was significantly lower than that of the successful cases. There were no significant differences in augmentation between anterior maxillary and mandibular implant sites. Autogenous bone grafting using in situ block bone is an effective and reliable approach for horizontal bone augmentation in the mandible and anterior maxilla that eliminates second donor site morbidity. Complete release of the buccal flap and tension-free suture is the key to avoiding wound dehiscence and ensuring the effectiveness of bone augmentation.

Pedicle Flap Designs for Soft Tissue Conditioning in the Therapy of Peri-implantitis.

Keratinized mucosa (KM) is regarded as a key factor in peri-implant health. A lack of KM has been associated with discomfort, higher plaque accumulation, and mucosal inflammation. Persistent inflammation might lead to progressive peri-implant bone loss. Several approaches to manage peri-implantitis have been advocated. Despite the effectiveness shown by surgical therapeutic modalities, soft tissue conditioning seems pivotal for long-term peri-implant health and stability. Free epithelial grafts have been demonstrated to efficiently augment the band of KM. Nevertheless, morbidity, dynamic soft tissue changes, and longer healing periods are shortcomings to be considered. The purpose of this technical note is to provide an alternative therapeutic modality for the surgical management of peri-implantitis combined with simultaneous soft tissue conditioning by means of pedicle flaps. Three main clinical scenarios are provided to conceive pedicle epithelial or connective tissue flaps, combined or not with collagen matrices, as predictable approaches to augment KM in the surgical therapy of peri-implantitis.

Autologous platelet-rich fibrin as a sole grafting material in regeneration of large periapical (palatal) defects: Report of four consecutive cases

The maintenance of a tooth with periapical lesion is more often managed by periradicular surgery when the efforts using conventional endodontic (re) treatment prove insufficient to achieve desired outcome. The most critical elements of successful bone regeneration involve the production hermetic seal of the endodontic canal after the root end resection and promotion of early uneventful wound healing using desirable biomaterials, particularly in large-sized intraosseous periapical defects. Yet even after the use of different biomaterials available, the wide varieties of such defects have shown suboptimal outcomes and also took longer healing period. The simple procurement method, ready bioavailability, cost-effectiveness, ease of handling, and remarkable healing potential of platelet-rich fibrin (PRF) in filling the large-sized periapical intrabony defects is presented in this article, with the aim of providing optimal and most elusive environment for wound healing in regenerative procedure. The entire intrabony defects were condensed with autologous PRF as the only grafting material in all four different cases for regeneration. The same surgical technique successfully applied to all four selected cases resulted in an uneventful healing post surgically and almost complete defect fill over 6 months' follow-up. The use of autologous PRF can be recommended for further research in view of its therapeutic use in large-sized intraosseous defects even in different health disciplines; to support the successful outcome identified in this case series.

Does Smoking Impair Bone Regeneration in the Dental Alveolar Socket?

Smoking is a major risk factor for dental implant failure. In addition to higher marginal bone loss around implants, the cellular and molecular responses to injury and implant physicochemical properties are also differentially affected in smokers. The purpose of this work is to determine if smoking impairs bone microstructure and extracellular matrix composition within the dental alveolar socket after tooth extraction. Alveolar bone biopsies obtained from Smokers (> 10 cigarettes per day for at least 10 years) and Ctrl (never-smokers), 7–146 months after tooth extraction, were investigated using X-ray micro-computed tomography, backscattered electron scanning electron microscopy, and Raman spectroscopy. Both Smokers and Ctrl exhibited high inter- and intra-individual heterogeneity in bone microstructure, which varied between dense cortical and porous trabecular architecture. Regions of disorganised/woven bone were more prevalent during early healing. Remodelled lamellar bone was predominant at longer healing periods. Bone mineral density, bone surface-to-volume ratio, mineral crystallinity, the carbonate-to-phosphate ratio, the mineral-to-matrix ratio, the collagen crosslink ratio, and the amounts of amino acids phenylalanine and proline/hydroxyproline were also comparable between Smokers and Ctrl. Bone microstructure and composition within the healing dental alveolar socket are not significantly affected by moderate-to-heavy smoking.

Graft of Small Patch of Partial Thickness in Equine Wound

Background: Cutaneous wounds in locomotor limbs represent one of the most frequent disorders in equine medicine. Wounds in equines are distinguished from those in other species by unique characteristics, including different healing rates among breeds, wound location and high propensity to formation of exuberant granulation tissue during the healing process. The wound healing process that cannot be sutured can be accelerated by the use of skin grafts, lowering the treatment cost.The objective of this report was to divulgate the success upon treatment of an extensive lacerated wound in the metatarsal region of a horse using autologous skin grafts.Case: A 3-year-old, female, American quarter horse weighting 450 kg was brought to veterinary hospital with lower limb injury. According to the owner’s report, the animal had one of its limbs stuck in a plain wire fence. A wound was observed in the metatarsal region during physical examination, the lesion caused an extensive skin laceration that showed the dorsal surface of the metatarsal bone and the digital extensor tendon. After injury assessment, wound debridement was carried out by surgery intervention followed by antisepsis and application of autologous plasma every two days as post-surgical care and wound preparation to receive the graft. Forty-five days after the first intervention, grafts were collected from the neck and implanted in the wound. The procedure achieved 70% of success. After approximately 75 days, transplantation was performed in other regions of the wound using the same technique. The duration of treatment at the Veterinary Hospital of the Universidade Paranaense (UNIPAR) was eight months, and then the animal returned home, where dressings were applied for two months to avoid the risk of contamination and until complete recovery.Discussion: The debridement of the wound and edges approximation were of great value in order to begin the process of wound granulation. The established therapy with scarring with gauze and use of antiseptics only in the initial stages of treatment, the frequent exchange of bandages every two days, preventing the accumulation of exudate and the use of autologous plasma favored the formation of the granulation bed and was sufficient to avoid infection and the formation of exuberant granulation tissue. Factors such as excessive movement and local infection were also attributed as responsible for the longer healing period, so the use of the spring coupled to the horseshoe decreased the joint movement, proving tobe effective in patients with severe extensor tendon lacerations. The use of the spring coupled to the horseshoe promoted a correct biomechanical alignment and no walking complication or deficiency was observed. The correct anatomical structural positioning prevents the formation of flexural deformities and fibrosis of the joint capsule. The use of micrografts wasbeneficial and simple to perform and the use of grafts contributed to a better cosmetic result. The main factor contributed to the grafting success was the use of dressing, which was regularly changed, and topical antimicrobial therapy correctly applied to avoid contamination. Based on the clinical result of this patient, it was concluded that the use of small autologous grafts can provide good recovery and healing of extensive wounds in horses when proper care with dressings and antimicrobial medication is provided after surgical interventions.Keywords: equine, surgery, graft, healing.

Osseointegration of Dental Implants in a Patient with Hajdu-cheney Syndrome.

Background:Hajdu-Cheney Syndrome (HCS) is a rare hereditary bone metabolism disorder characterized by acro-osteolysis, short stature, craniofacial changes, periodontitis and premature tooth loss. Extensive search of the current literature revealed no reports of implant placement in patients with HCS.Case Report:A 22-year old woman with osteoporosis, generalized advanced chronic periodontitis and premature tooth loss was referred to the Postgraduate Clinic of Periodontology, University of Athens-Greece. The patient was diagnosed in 2001 with HCS. The patient received non-surgical periodontal treatment and several teeth were extracted due to extensive alveolar bone loss.After careful consideration of the possible implications deriving from the patient’s condition and having taken her young age into account, initially, a dental implant was placed in the upper right first premolar region. Specific protocols such as longer healing periods were implemented, so five years after placement and successful osseointegration of this implant, four additional dental implants were placed in the posterior regions of the maxilla and the mandible. Prosthetic rehabilitation followed 6 months after implant placement. Upon completion of periodontal treatment, the patient was enrolled in a periodontal maintenance program.Results:Clinical and radiographic examination of the patient during the periodontal maintenance program after implant placement revealed no abnormalities in the implant region.Conclusion:Patients with HCS suffer from periodontitis, bone destruction and premature tooth loss. This case indicates the successful osseointegration of dental implants in patients with HCS. However, further research is required in order to determine the predictability of dental implant placement in those patients.

The effect of experimental osteoporosis on bone regeneration: Part 1, histology findings.

To histologically define the healing events occurring in calvarial critical size defects (CSDs) following treatment with a collagen barrier for guided bone regeneration (GBR) and a particulate graft in healthy and osteoporotic conditions. Thirty-six 10-month-old, female, Wistar rats were used in this study. Half of them were ovariectomized (OVX) and fed with a low-calcium diet to induce an osteoporotic-like status. In each animal of both groups, two 5-mm CSDs were created, one in the centre of each parietal bone, and they were treated with a deproteinized bovine bone mineral (DBBM) particulate graft and a bi-layer collagen membrane. Six OVX and six healthy control rats were randomly euthanized at 7, 14 and 30days. One defect per animal was randomly processed for decalcified histology. Three central sections were used for qualitative histology and histomorphometric analysis. No significant difference in terms of percentage of newly formed bone was detected between the two groups at the different healing periods. However, a trend towards less bone formation and of poorer quality, expressed as reduced bone maturation, was detected in the OVX animals at 30days. According to this study, GBR with a collagen barrier and a DBBM graft can be successfully obtained also in osteoporotic-like conditions. Future studies considering longer healing periods and controlling for the confounding factors arising from the use of a particulate graft are needed to confirm these data.

In Vivo Evaluation of Commercially Available Gel-Type Polyethylene Glycol Membrane for Carrier of Recombinant Human Bone Morphogenetic Protein-2

This study evaluated a commercially available, 3-dimensional gel-type polyethylene glycol (PEG) membrane as a carrier for recombinant human bone morphogenetic protein-2 (rhBMP-2) using a rat calvarial defect model. Another gel-type carrier, fibrin-fibronectin system (FFS), was used as a positive control. Critical-size defects were made in the rat calvarium, which were allocated to 1 of 10 groups comprising 2 healing periods and biomaterial conditions: 1) sham control, 2) FFS only, 3) FFS plus BMP-2, 4) PEG only, and 5) PEG plus BMP-2. Radiographic and histologic analyses were performed at 2 and 8weeks after surgery. After 2weeks, some parts of the FFS were biodegraded and extensive cellular infiltration was observed at sites that received FFS or FFS plus BMP-2. The PEG membrane retained its augmented volume without cellular infiltration at sites that received PEG or PEG plus BMP-2. After 8weeks, the FFS was completely degraded and replaced by new bone and connective tissues. In contrast, the volume of residual PEG was similar to that at 2weeks, with slight cellular infiltration. In particular, there was progressive bone regeneration around micro-cracks and resorbed outer surface in the PEG+ BMP-2 group. Although the PEG+ BMP-2 group showed increased area and percentage of new bone, there was no statistical relevance after 2 and 8weeks in histomorphometric analyses. However, the appearance of the healing differed (with new bone formation along micro-cracks in the PEG+ BMP-2 group), and further studies with longer healing periods are needed to draw conclusions about clinical applications. Evidence of mechanical stability and new bone formation along micro-cracks when using PEG plus BMP-2 might support the PEG membrane as a candidate carrier material for rhBMP-2.

STUDY ON THE BIODEGRADABILITY OF FeMnSi ALLOY

A biodegradable iron based alloy was obtained through classical melting method using a furnace with controlled atmosphere. The metallic material was obtained from high purity materials using a proper obtaining method. The material is proposed as an alternative to magnesium alloys that have a very fast degradation period for applications with longer healing periods (more than 3 and between 12 to 18 months). The material was analyzed using scanning electron microscopy (SEM) and X-ray dispersive energy analyze EDAX, before and after implantation to observe the influence of the human medium on the metallic implant. Both implantation areas (subcutaneous and in bone) indicate reactions with the biological environment as compounds form on the surface or with loss of metallic material. Bio-chemistry of Ca, P and Mg of the implanted subjects was realized for subcutaneous and in bone implantation comparing with the results of a Zr implant behavior. In vivo experiment on Wistar rats highlight a very good bio-compatibility of the subcutaneous implant by the absence of any kind of local reaction or toxic systemic fact, which is explained by slow degradation of FeMnSi alloy and the metabolism of resulted products in conditions of maintaining organism homeostasis.

Clinical and radiographic evaluation of early loaded narrow-diameter implants: 3years follow-up.

To evaluate the clinical reliability of narrow implants placed in a one-stage procedure and early loaded in the upper and lower incisor region. This is a prospective, single-arm, multicenter study in which patients with missing natural dentition in upper lateral and lower incisor positions were enrolled. Eligible implants (OsseoSpeed™ TX 3.0S, DENTSPLY Implants) were of three different lengths and of 3.0 mm in diameter. One-stage surgery was performed and healing abutment connection took place. Placement of the permanent single crown took place after a 6-10 weeks healing period. Clinical and radiographic checks were performed at implant placement, loading, and at the 6, 12, 24, and 36 months follow-up visits. A total of 69 subjects with 97 implants have been included in this study. From surgery to 36 months follow-up, 5.6% of the implants showed bone loss of more than 1 mm, while no bone loss at all were observed for 57.3% of the implants. The mean marginal bone level change from surgery to the 6, 12, and 36 months follow-up visits was -0.27, -0.11, and -0.09 mm, respectively. The total survival rate after 3 years is 95.5%. The data presented show stable marginal bone levels as well as healthy soft tissue around OsseoSpeed™ TX 3.0S implants, after 3 years of function. An interesting finding from this investigation was that a longer healing period before crown placement and loading contributed to statistically significant less marginal bone loss between loading and the 1-year follow-up visit (Galindo-Moreno et al. 2012). This finding, associated with a stable probing pocket depth and a stable crown-gingiva distance, using a one-stage surgical procedure helps to maintain the integrity of the peri-implant soft tissues. Narrow implants can be considered as a valid solution in the treatment of the localized narrow bony defects in the anterior area with reduced spaces between the natural teeth.

Reversibility of experimental peri‐implant mucositis compared with experimental gingivitis in humans

To monitor clinical, microbiological and host-derived alterations occurring around teeth and titanium implants during the development of experimental gingivitis/mucositis and their respective healing sequence in humans. Fifteen subjects with healthy or treated periodontal conditions and restored with dental implants underwent an experimental 3-week period of undisturbed plaque accumulation in the mandible. Subsequently, a 3-week period with optimal plaque control was instituted. At Days 0, 7, 14, 21, 28, 35 and 42, the presence/absence of plaque deposits around teeth and implants was assessed, (plaque index [PlI]) and the gingival/mucosal conditions were evaluated (gingival index[GI]). Subgingival/submucosal plaque samples and gingival/mucosal crevicular fluid (CF) samples were collected from two pre-determined sites around each experimental unit. CF samples were analyzed for matrix-metalloproteinase-8 (MMP-8) and interleukin-1beta (IL-1β). Microbial samples were analyzed using DNA-DNA hybridization for 40 species. During 3 weeks of plaque accumulation, the median PlI and GI increased significantly at implants and teeth. Implant sites yielded a greater increase in the median GI compared with tooth sites. Over the 6-week experimental period, the CF levels of MMP-8 were statistically significantly higher at implants compared with teeth (P<0.05). The CF IL-1β levels did not differ statistically significantly between teeth and implants (P>0.05). No differences in the total DNA counts between implant and tooth sites were found at any time points. No differences in the detection frequency were found for putative periodontal pathogens between implant and tooth sites. Peri-implant soft tissues developed a stronger inflammatory response to experimental plaque accumulation when compared with that of their gingival counterparts. Experimental gingivitis and peri-implant mucositis were reversible at the biomarker level. Clinically, however, 3 weeks of resumed plaque control did not yield pre-experimental levels of gingival and peri-implant mucosal health indicating that longer healing periods are needed.

Outcomes of Dental Implants in Osteoporotic Patients. A Literature Review

This article reviews available data on the outcome of dental implants in osteoporotic patients. A search was performed in PubMed and completed in July 2007. The keywords "dental AND implants AND osteoporosis," "dental AND implants AND age," "dental AND implants AND gender," and "dental AND implants AND bone AND quality," with no limitations for language or year of publication, resulted in 82, 598, 94, and 541 articles, respectively. After abstract scanning (in case of doubt the article was read), 39 nonreview articles studying dental implant outcomes in osteoporotic/osteopenic subjects remained for our review. The bibliographies of the 39 articles were also inspected, but no additional studies were identified. Thirteen of 16 animal studies found lower osseointegration rates in osteoporotic/osteopenic bone than in normal bone. Six in nine clinical reports mention success. Eight of 12 studies in humans support the applicability of dental implants in osteoporotic patients. There are no data to contraindicate the use of dental implants in osteoporotic patients; however, a proper adjustment of the surgical technique and a longer healing period may be considered in order to achieve osseointegration. Data on the use of biphosphonates in osteoporotic patients and implant outcomes are very limited, and no conclusions can be drawn. In addition, large prospective studies investigating the long-term success of dental implants in osteoporotic individuals are required.

Biologic width changes around loaded implants inserted in different levels in relation to crestal bone: histometric evaluation in canine mandible

The aim of the present study was to evaluate histometric changes around dental implants inserted at different levels in relation to the crestal bone, under different loading conditions. Thirty-six implants were inserted in the edentulous mandible of six mongrel dogs. Each implant was assigned to an experimental group according to the distance from the top of the implant to the crestal bone: Bone Level (at the crestal bone level), Minus 1 (1 mm below the crestal bone) or Minus 2 group (2 mm below the crestal bone). Each hemimandible was submitted to a loading protocol: conventional or immediate restoration. After 90 days, the animals were killed. Specimens were processed, and measurements were performed concerning the length of soft and hard peri-implant tissues. Data were analyzed using ANOVA and Student's t test (alpha=5%). Among conventionally restored sites, the distance from the most coronal position of soft tissue margin (PSTM) and first bone-implant contact (fBIC) was greater for Minus 2 than for Bone Level and Minus 1 sites (P=0.03), but significant differences were not observed among immediately restored sites. Differences among groups were not observed concerning the PSTM, and the distance from the implant-abutment junction to fBIC. Greater amounts of lateral bone loss were observed for conventionally than for immediately restored sites (P=0.006). These findings suggest that the apical positioning of the top of the implant may not jeopardize the position of soft peri-implant tissues, and that immediate restoration can be beneficial to minimize lateral bone loss. Further studies are suggested to evaluate the clinical significance of these results in longer healing periods.

Clinical and Radiographic Changes Around Dental Implants Inserted in Different Levels in Relation to the Crestal Bone, Under Different Restoration Protocols, in the Dog Model

The aim of the present study was to evaluate clinical and radiographic changes that occur around dental implants inserted in different levels in relation to crestal bone under different restoration protocols. Thirty-six implants were inserted in the edentulous mandible of six mongrel dogs. Each implant was assigned to an experimental group according to the distance from the top of the implant to the crestal bone: Bone Level (at crestal bone level), Minus 1 (1 mm below crestal bone), or Minus 2 (2 mm below crestal bone). Each hemimandible was submitted to a restoration protocol: conventional (prosthesis was installed 120 days after implant placement, including 30 days with healing cap) or immediate (prosthesis was installed 24 hours after implant placement). Fixed partial prostheses were installed bilaterally in the same day. After 90 days, clinical and radiographic parameters were evaluated. As long as the implants were inserted in more apical positions, the first bone-to-implant contact (fBIC) was positioned more apically (P <0.05). However, the apical positioning of the implants did not influence the ridge loss or the position of the soft tissue margin (PSTM) (P >0.05). In addition, in immediately restored sites, the PSTM was located significantly more coronally than that in conventionally restored sites (P = 0.02). Despite the more apical positioning of the fBIC, the height of the peri-implant soft tissues and ridge was not jeopardized. Moreover, the immediate restoration protocol was beneficial to the maintenance of the PSTM. Further studies are suggested to evaluate the significance of these results in longer healing periods.

Crown Lengthening in the Esthetic Zone

Crown lengthening in the esthetic zone is a prosthodontically designed and surgically executed procedure that must only be considered after careful restorative and surgical treatment planning, including a detailed smile analysis, clinical and radiographic evaluation of the quality of soft and hard tissues, and selection of the appropriate approach for each individual case. The presented techniques are modifications of the original conventional surgical approach, where longer healing periods may have been required and loss of papilla height or fullness is of concern. Recognition of the advantages and disadvantages of each technique should increase predictability and success in interdisciplinary smile enhancement therapy.

Regeneration of Rat Calvarial Defects Using a Bioabsorbable Membrane Technique: Influence of Collagen Cross‐linking

The aim of the present study was to examine the influence of cross-linking on collagen membranes used for guided bone regeneration of calvarial defects in rats. In 48 Wistar rats, divided equally into 4 groups, 1 control and 3 experimental, standardized transosseous circular calvarial defects were made midparietally. In the control group, the defect was only covered by the soft tissue flap while in the 3 experimental groups, 3 differently cross-linked collagen membranes were interposed between the osseous defect and the overlying flap before suturing. The healing was assessed at 10, 20, and 30 days after surgery. The results showed that augmenting the degree of collagen cross-linking diminished the membrane resorption rate. Compared to the sham-operated sites, the membrane protected defects showed significantly more bone regeneration (on average 4 times more) as attested by histology and measured by histomorphometric analysis. Although the bone gain seemed to augment with increasing degrees of cross-linking, the results within the 3 experimental groups were not statistically different. Since longer healing periods might have been necessary to substantiate results within experimental groups, a study is currently undertaken to evaluate this aspect. This study demonstrated the efficacy of collagen membranes in guiding bone regeneration, as well as the importance of the type and degree of cross-linking.

Advantage or Disadvantage of Episiotomy Compared with Spontaneous Perineal Laceration

In a prospective clinical investigation of 2,144 deliveries, we elucidate the indications for episiotomy and how different methods of anesthesia affect the frequency of episiotomy and the perineal problems after episiotomy compared with those after spontaneous perineal laceration. We found a significantly higher infection rate (p less than 0.001) and a longer healing period in the episiotomy group. These differences remain even if only primigravida or the indication, imminent perineal laceration, is studied. The results indicate that many women will unnecessarily suffer after an episiotomy. The patient's subjective problems are significantly increased, both immediately and at the 3-month postoperative follow-up.

The effects of citric acid on attachment of laterally positioned flaps.

Citric acid demineralization of root surfaces to enhance new attachment clinically appears to be successful, but histologic evidence of new attachment in humans is lacking. Two recession-like defects were surgically created on the facial aspect of mandibular incisors scheduled for extraction in five patients. Each patient had differing degrees of periodontal disease, but the control and experimental teeth of each were similarly involved. The roots were thoroughly planed and an apical reference notch was inscribed just coronal to crestal bone. One tooth served as the control, while the experimental tooth was treated with citric acid (pH 1) for two minutes. Two full-thickness laterally positioned flaps were done to cover the roots. After healing periods of 1, 2, 4, 12, and 20 weeks, the teeth were removed by block section for histologic evaluation. The type of attachment differed on the teeth with longer healing periods. The control teeth exhibited a long epithelial attachment with no evidence of cementogenesis, whereas the experimental teeth had a connective tissue attachment to newly formed cementum coronal to the reference notch. These observations provide evidence that demineralization of root surfaces may promote increased or accelerated connective tissue attachment of laterally positioned flaps.