Comparing the clinical effects of local administration of minocycline ointment and doxycycline solution in the treatment of acute periodontal abscesses: a retrospective clinical study.

PURPOSE: The objective of this retrospective clinical study was to provide evidence supporting the adjunctive local application of doxycycline solution or minocycline ointment, in conjunction with drainage, for the treatment of acute periodontal abscesses. METHODS: The study included 63 patients who had received treatment for acute periodontal abscesses through drainage supplemented with 1 of 3 types of adjunctive medications during their initial visit (visit 1; baseline): 1) saline irrigation (the control group), 2) 2% minocycline ointment (the TM group), or 3) 300 mg/mL doxycycline irrigation (the TD group). The same adjunctive medication was administered at visit 2, which took place 1 week after visit 1. Probing depth (PD), bleeding on probing (BOP), plaque index, gingival recession, clinical attachment level, and tooth mobility were clinically evaluated at visits 1, 2, and a third visit (visit 3; 4 weeks after visit 1). Statistical significance was considered to be indicated by P values <0.05. RESULTS: By visit 3, all clinical indices and tooth mobility had significantly decreased in each group. At this visit, PD and BOP on the abscess side were significantly lower in the TM and TD groups compared to the control group. The TD group showed a significantly greater improvement than the TM group, with mean PD reductions of 1.09 mm in the control group, 1.88 mm in the TM group, and 2.88 mm in the TD group. Similarly, mean BOP reductions were 45% in the control group, 73.02% in the TM group, and 95.45% in the TD group. CONCLUSIONS: Local and adjunctive administration of doxycycline and minocycline in combination with drainage exhibited clinical advantages over drainage alone in improving PD and BOP. Notably, a doxycycline solution of 300 mg/mL was more effective than a 2% minocycline ointment.

Quantitative investigation of the bacterial content of periodontal abscess samples by real-time PCR.

OBJECTIVES: Periodontal abscesses, which are part of the acute periodontal disease group characterized by the destruction of periodontal tissue with deep periodontal pockets, bleeding on probing, suppuration, and localized pus accumulation, cause rapid destruction of tooth-supporting tissues. This study aimed to evaluate the microbial content of periodontal abscesses by specific and culture-independent qPCR. METHODS: This study was conducted on 30 volunteers diagnosed with periodontal abscesses and presenting with complaints of localized pain, swelling, and tenderness in the gingiva. Genomic DNA was isolated from the samples taken. Escherichia coli bacteria were used for the standard curve created to calculate the prevalence of target bacteria in the total bacterial load. 16S rRNA Universal primers were used to assess the total bacterial load and prevalence. Bacterial counts were analyzed with Spearman's rank correlation coefficients (ρ) matrix. RESULTS: From the analysis of Real-Time PCR, Porphyromonas gingivalis (30, 100%), Prevotella intermedia (30, 100%), and Fusobacterium nucleatum (30, 100%) were detected in all samples. Campylobacter rectus (29, 96.6%), Porphyromonas endodontalis (29, 96.6%), Tannerella forsythia (28, 93.3%), Filifactor alocis (28, 93.3%), and Actinomyces naeslundii (28, 93.3%) were also frequently detected. CONCLUSIONS: Periodontal abscesses were found to be polymicrobial, and not only periodontal pathogens appeared to be associated with the development of periodontal abscesses. The presence, prevalence, and number of Porphyromonas endodontalis and Propionibacterium acnes in the contents of periodontal abscesses were determined for the first time in our study. Further studies are needed to better understand the roles of bacteria in periodontal disease, including abscesses.

Patient on Hemodialysis Develops Painful Periodontal Abscess and Presents for Treatment.

Dialysis patients have an increased risk of acquiring hepatitis B, hepatitis C, and HIV because the dialysis machine is disinfected, not sterilized. Therefore, the dentist must follow standard precautions for infection control when treating dialysis patients. Following the medical complexity status (MCS) system, the patient can be designated as MCS 2B category.

Post-COVID mucormycosis in presentation of periodontal abscess.

COVID-19 pandemic has traumatized deep inside in minds and lives of human beings. Those who have survived are at risk of many post-COVID complications; mucormycosis being one of the most common as well as morbid infections. Mucormycosis is also known as black fungus, it is a life-threatening opportunistic fungal infection. Inoculation occurs by inhalation of spores in nose, paranasal air sinuses and in lungs. Mucormycosis is often associated in patients with compromised immunity and it presents with characteristic black necrotic eschar and necrosis. Disease affecting the facial region possess a challenge because it often disseminates with sino-orbital and cranial involvement at the time of diagnosis. Dental practice occasionally encounters unusual and subtle symptoms with non-pathognomonic clinical signs of several fatal diseases which may pretend like a common oral disease. Hence, the key knowledge to oral and primary care physicians and its precise application is necessary for the early diagnosis of such fatal infections to prevent untoward consequences in this COVID era. This article presents a case of mucormycosis with chief complaint of pain and swelling in right front tooth region, which mimicked as periodontal abscess in a patient, leading to delay in the diagnosis possess greater challenges during the treatment.

Multiple maxillary periodontal abscesses as a manifestation of post-coronavirus disease 2019 mucormycosis: a case report.

BACKGROUND: Coronavirus disease 2019 makes patients more susceptible to superinfection of fungal disease as a consequence of immunological system impairment. Mucormycosis is a fungal infection that is rare but has a high mortality rate and mostly affects patients with poorly controlled diabetes mellitus or those receiving corticosteroids. CASE PRESENTATION: Here, we present a case of post-coronavirus disease 2019 mucormycosis in a 37-year-old Persian male presenting with multiple periodontal abscess with purulent discharge and necrosis of maxillary bone (without oroantral communication). Surgical debridement following antifungal therapy was the treatment of choice. CONCLUSION: Early diagnosis and immediate referral are the cornerstone of comprehensive treatment.

Multi-disciplinary treatment of severe palatal radicular groove of maxillary lateral incisor: A case report and literature review. / 上颌侧切牙重度畸形舌侧沟多学科联合治疗1ä¾‹å¹¶æ–‡çŒ®å¤ä¹ .

Palatal radicular groove is a developmental malformation of maxillary incisors, lateral incisors in particular, which often causes periodontal destruction. This paper reports a case of combined periodontal-endodontic lesions induced by palatal radicular groove, which was initially misdiagnosed as a simple periapical cyst. After root canal therapy and periapical cyst curettage, the course of disease was prolonged, resulting in the absence of buccal and maxillary bone plates in the affected tooth area. After the etiology was determined, the affected tooth was extracted and guide bone tissue regeneration was performed at the same time, followed by implantation and restoration at the later stage, leading to clinical cure. The palatal radicular groove is highly occult, and the clinical symptoms are not typical. If the abscess of the maxillary lateral incisor occurs repeatedly, and the abscess of the maxillary lateral incisor has not been cured after periodontal and root canal treatment, cone-beam computed tomographic and periodontal flap surgery should be considered.

Actinomycosis of periodontium, mimicking gingival enlargement - A case report and its management.

Gingival abscess is a localized, acute inflammatory lesion which is caused by various factors that include microbial plaque infection, foreign body impaction, and trauma. Management includes a simple incision and draining of the purulent exudate along with systemic antibiotics in most of the cases. This article reports a case of a 16-year-old female patient, with a chief complaint of painful and swollen gums in her lower right front tooth region of the jaw along with fever for the past 5 days. Emergency treatment of abscess drainage was done on day 1. On 5th day of review, the case presented with persistent signs of gingival inflammation in relation to 43 to 41. Considering the provisional diagnosis as dentigerous cyst with persistent gingival abscess, definitive treatment was performed by transalveolar extraction of the impacted canine and debridement of the osseous lesion. The histologic analysis of the lesion exhibited foci of eosinophilic coagulum-like areas with epicentric and radiating filamentous appearance at the periphery, which is suggestive of an inflamed dentigerous cyst with actinomycosis infection of periodontium.

Multi-disciplinary treatment of severe palatal radicular groove of maxillary lateral incisor: A case report and literature review / 中南大学学报(医学版)

Palatal radicular groove is a developmental malformation of maxillary incisors, lateral incisors in particular, which often causes periodontal destruction. This paper reports a case of combined periodontal-endodontic lesions induced by palatal radicular groove, which was initially misdiagnosed as a simple periapical cyst. After root canal therapy and periapical cyst curettage, the course of disease was prolonged, resulting in the absence of buccal and maxillary bone plates in the affected tooth area. After the etiology was determined, the affected tooth was extracted and guide bone tissue regeneration was performed at the same time, followed by implantation and restoration at the later stage, leading to clinical cure. The palatal radicular groove is highly occult, and the clinical symptoms are not typical. If the abscess of the maxillary lateral incisor occurs repeatedly, and the abscess of the maxillary lateral incisor has not been cured after periodontal and root canal treatment, cone-beam computed tomographic and periodontal flap surgery should be considered.

Factores etiológicos de abscesos periodontales: Una patología emergente. Informe de tres casos / Etiological factors of periodontal abscesses: an emerging pathology. A three-case report

Introducción: La presencia de abscesos periodontales es la tercera emergencia dental más frecuente (6%-14%). Objetivo: Reportar información sobre diferentes factores etiológicos de absceso periodontal en tres pacientes. Descripción de casos: Primer caso, mujer de 52 años quien acudió a consulta por sangrado espontáneo, al examen clínico se evidenció sangrado al sondaje (SS), presencia de bolsas periodontales (BP) y cálculos (C); como tratamiento se realizó raspado y alisado radicular (RAR), complementado con detoxificación con tetraciclina y tratamiento farmacológico posoperatorio. Segundo caso, hombre de 27 años quien acudió a consulta por agrandamiento de encía, se observó (SS), y (BP); se retiró la lesión y se realizó (RAR). Tercer caso, hombre de 21 años quien acudió a consulta de control, al examen clínico se evidenció presencia de cálculos en órganos dentarios y bolsas periodontales en órganos dentarios 16-17; se utilizó (RAR) complementado con detoxificación con tetraciclina y tratamiento farmacológico posoperatorio. Conclusión: La etiología del absceso periodontal en el primer y último caso se basó en la falta de profundidad durante el raspado y alisado radicular, y en el segundo estuvo relacionado a impactación de alimentos. El identificar la etiología permite determinar diagnóstico, pronóstico y tratamiento ideal.

Introduction: Periodontal abscesses are the third most frequent dental emergency (6%-14%). Objective: To describe different etiological factors of periodontal abscesses in three patients. Case description: The first case was a 52-year-old woman who sought treatment due to spontaneous bleeding. During the examination, she revealed bleeding on probing (BP), presence of periodontal pockets (PP), and calculi (C). Scaling and root planning (SRP) was performed as treatment, which was complemented with detoxification with tetracycline and postoperative pharmacological treatment. The second case was a 27-year-old man who came to the clinic due to gum enlargement and showed BP and PP. The lesion was treated and SRP was performed. Finally, the third patient was a 21-year-old male who sought a follow-up consultation. The clinical examination showed the presence of dental calculi and periodontal pockets in teeth 16 and 17. SRP complemented with detoxification with tetracycline and postoperative pharmacology were used as treatments. Conclusion: The etiology of the periodontal abscesses in the first and third cases was based on the lack of depth during root scaling and planning. The cause in the second case was effects of food. Identifying this etiology is useful to achieve proper diagnosis, prognosis and treatment of periodontal abscesses.

Should systemic antibiotics be prescribed in periodontal abscesses and pericoronitis? A systematic review of the literature.

This study assessed whether systemic antibiotics are beneficial or harmful in patients who present with an acute periodontal abscess or pericoronitis, with or without systemic involvement, and, if antibiotics are beneficial, which type, dosage, and duration are the most effective. Medline, Embase, and the Cochrane Library were screened from 1948 up to 1 April 2022 for systematic reviews, randomised clinical trials (RCTs), and other studies. Dedicated websites were consulted for systematic reviews, clinical practice guidelines, and health technology assessments on the topic. Outcomes of interest comprised tooth survival, swelling, pain, tooth mobility, periodontal probing depth, suppuration, adverse effects, quality of life measurements, and medication required for pain relief. Overall, five guidelines, seven systematic reviews, 15 RCTs, and 34 other studies were identified and selected for full-text assessment, but none of them fulfilled the inclusion criteria. At present there is no single randomised or non-randomised controlled trial assessing the harms and clinical effectiveness of systemic antibiotics in adults with a periodontal abscess or pericoronitis.

Comparison Study of Diagnosis and Treatment Planning for Dental Infections between Dental Students and Practitioners.

This study aimed to access the knowledge in diagnosing dental infections and the practice in treatment planning for the affected teeth among dental practitioners (DPs) and senior (final-year) students. A survey questionnaire containing two cases (Case A; periodontal abscess and Case B; periapical abscess) with four questions per case was delivered to potential participants. Fifty-nine DPs voluntarily participated in the survey. For senior students, the case study was a part of their course requirements; one of the two cases (either Case A or B) was randomly assigned to the 126 seniors. The distribution of responses was significantly different between the DP and senior groups except for the diagnosis of Case B (Fisher's exact test; p = 0.05). Only 31% of the participants diagnosed Case A as periodontal abscess; most of them selected periodontal surgery as the first treatment option. Despite a high agreement in diagnosing Case B, the choice of treatment was significantly different; the most frequent treatment option was extraction (51%) from the DP group and root canal retreatment (57%) from the senior group. The study revealed that the diagnosis of periodontal abscess was more challenging than that of periapical abscess among dental professionals.

Arte y ciencia en el diagnóstico de la enfermedad periodontal atípica: reporte de caso / Art and science in the diagnosis of atypical periodontal disease: case report

Las lesiones pulpares y periodontales son las más prevalentes en la cavidad bucal y, tal vez por ello, son las causas más frecuentes de consulta odontológica en nuestro medio y en el mundo. Estas patologías tienen principalmente, etiología bacteriana y una flora polimicrobiana. Las estructuras anatómicas e histológicas de los tejidos periodontales y pulpares presentan interrelaciones, que deben considerarse en la etiopatología de sus procesos. El diagnóstico de las lesiones endoperiodontales no siempre se puede definir claramente, lo cual crea vacíos que dificultan el diagnóstico de las enfermedades pulpares y periodontales. El odontólogo debe estar preparado y entrenado para que le sea posible definir el diagnóstico diferencial de las dos enfermedades y brindar un tratamiento eficiente. Se reporta un caso clínico, donde el manejo del examen clínico, así como de la anatomía endoperiodontal, son decisivos para llegar al diagnóstico correcto y el tratamiento oportuno y adecuado. (AU)

Pulp and periodontal lesions are the most prevalent in the oral cavity, and are the most frequent causes of dental consultation in our environment and in the world. These pathologies are mainly of bacterial etiology, with a polymicrobial flora. The anatomical and histological structures of the periodontal and pulp tissues present interrelationships that must be taken into account in the etiopathology of these processes. The diagnosis of endoperiodontal lesions is not always clearly defined, which constitutes certain gaps for the diagnosis. The dentist must be trained to perform the differential diagnosis of these two diseases and provide efficient treatment in our patients. A clinical case is reported, where the management of the clinical examination as well as the endoperiodontal anatomy is important to reach the correct diagnosis and its subsequent treatment. (AU)

Characterization and Antimicrobial Susceptibility of Pathogens Associated with Periodontal Abscess.

Knowledge of microbial composition and antimicrobials' susceptibility to periodontal abscesses is vital for their successful treatment. The current study aims to provide a thorough overview of the clinical and microbial features of periodontal abscesses of the local community. The study was carried out at Rehman College of Dentistry, Peshawar, Pakistan between December 2019 to March 2020. Clinical measurements and microbial samples were collected from 45 subjects. Microbial samples were anaerobically cultured for the growth of selected bacterial species. E-test was used to assess the susceptibility of bacterial species grown from the patient samples to amoxicillin, azithromycin, metronidazole, and tetracycline. The majority of affected patients had preexisting chronic periodontitis. All abscesses clinically demonstrated bleeding on probing and suppuration. The periodontal abscess was most commonly associated with lower incisors and canines, followed by lower molars and then upper incisor and canine teeth. Fusobacterium spp. (73%) was the most frequently detected species followed by Prevotella intermedia/nigrescens (65%), Porphyromonas gingivalis (46%) and Aggregatibacter actinomycetemcomitans (24%). The detected clinical isolates of certain bacteria demonstrated resistance to all tested antibiotics except azithromycin. We conclude that Fusobacterium spp., P. intermedia/nigrescens, P. gingivalis, C. rectus, T. forsythia and A. actinomycetemcomitans are closely associated with periodontal abscess. Bacterial species associated with periodontal abscess demonstrated some level of antimicrobial resistance to amoxicillin, metronidazole and tetracycline while antibiotic resistance to azithromycin could not be demonstrated.

Detection rates of periodontal bacteria and herpesviruses in different forms of periodontal disease.

The aim was to investigate the detection rates of periodontal bacteria (Porphyromonas gingivalis, Tannerella forsythia, Prevotella intermedia, and Aggregatibacter actinomycetemcomitans) and herpesviruses (herpes simplex virus-1 [HSV-1], cytomegalovirus [CMV], and Epstein-Barr virus [EBV]) in different forms and severity of periodontal disease, and to compare them with those in periodontally healthy subjects. One hundred and twenty-nine patients participated in the study: 39 diagnosed with periodontal abscess (PA), 33 with necrotizing ulcerative periodontitis (NUP), 27 with chronic periodontitis (CP), and 30 participants with healthy periodontal tissue represented a healthy control group. All patients with periodontal disease (PA, NUP, and CP) were also divided into two groups according to the severity of their disease: moderate and severe periodontitis. The subgingival samples were collected from the periodontitis active sites and the detection of microorganisms was performed by end-point polymerase chain reaction analyses. The results revealed significantly higher detection rates of P. gingivalis, T. forsythia, and P. intermedia in all three groups of patients with periodontitis than in healthy participants. The highest detection rate of A. actinomycetemcomitans was noticed in CP, which was significantly higher than that in PA, NUP, and healthy control. The occurrence of EBV was significantly higher in NUP than in CP and healthy participants. CMV was detected significantly more frequently in PA and NUP than in CP and healthy participants. Comparisons among healthy participants and patients with moderate and severe periodontitis showed significantly higher detection rates of EBV and CMV in patients with severe forms of periodontitis than in healthy participants and those with moderate periodontitis.

Common Dental and Periodontal Diseases.

Oral health is a critical component of overall health and well-being. Dental caries and periodontitis are two of the most common oral diseases and, when not treated, can have irreversible sequelae and overall psychosocial and physiologic impact on individuals, diminishing quality of life. The burden of advanced dental caries and periodontal disease leading to tooth loss is severe. Physicians and allied medical professionals can help in early detection of dental caries, abscess, and periodontal diseases and initiate management followed by prompt referral to dental colleagues.

Ludwig's Angina in Pregnancy: A Case Report.

BACKGROUND: Physiologic changes in pregnancy may predispose pregnant women to oral health problems. However, most women are not counselled on oral health during pregnancy. Lack of proper oral health care predisposes pregnant women to odontogenic infections, which can lead to severe complications. CASE: A 34-year-old multiparous woman presented at 400 weeks gestation with a 3-day history of severe, progressive neck swelling, jaw pain, and trismus. She was diagnosed with Ludwig's angina secondary to an untreated dental cavity. She required emergency fiberoptic intubation to secure her airway, urgent delivery via cesarean section, and subsequent surgical drainage performed by otolaryngology. CONCLUSION: Ludwig's angina during pregnancy is associated with severe morbidity. Dental care should not be denied or postponed due to pregnancy, and dental infections should be treated promptly. Health care providers should counsel women on the importance of maintaining good oral health during pregnancy.

Management of Acute Periodontal Abscess Mimicking Acute Apical Abscess in the Anterior Lingual Region: A Case Report.

Purulent infections of periodontal tissues are known as periodontal abscesses localized to the region of the involved tooth. Due to the high prevalence rate and aggressive symptoms, it is considered a dental emergency; urgent care is mandatory to maintain the overall health and well being of the patient. This case report describes the management of a patient who presented with an acute periodontal abscess secondary to poor oral hygiene. Clinically and radiographically, the lesion was mimicking an acute apical abscess secondary to pulpal necrosis. Periodontal treatment was started after completion of antibiotic therapy. The clinical presentation of the condition and results of the recovery, along with a brief review of relevant literature are discussed.

Microbiota in Human Periodontal Abscess Revealed by 16S rDNA Sequencing.

Periodontal abscess is an oral infective disease caused by various kinds of bacteria. We aimed to characterize the microbiota composition of periodontal abscesses by metagenomic methods and compare it to that of the corresponding pocket and healthy gingival crevice to investigate the specific bacteria associated with this disease. Samples from abscess pus (AB), periodontal pocket coronally above the abscess (PO), and the gingival crevice of the periodontal healthy tooth were obtained from 20 periodontal abscess patients. Furthermore, healthy gingival crevice samples were obtained from 25 healthy individuals. Bacterial DNA was extracted and 16S rRNA gene fragments were sequenced to characterize the microbiota and determine taxonomic classification. The beta-diversity analysis results showed that the AB and PO groups had similar compositions. Porphyromonas gingivalis, Prevotella intermedia, and other Prevotella spp. were the predominant bacteria of human periodontal abscesses. The abundances of Filifactor alocis and Atopobium rimae were significantly higher in periodontal abscesses than in the periodontal pocket, suggesting their association with periodontal abscess formation. In conclusion, we characterized the microbiota in periodontal abscess and identified some species that are positively associated with this disease. This provides a better understanding of the components of periodontal abscesses, which will help facilitate the development of antibiotic therapy strategies.

[Acquisition and the immunogenicity of the outer membrane FomA protein of Fusobacterium nucleatum].

Objective: To express and purify outer membrane protein FomA of Fusobacterium nucleatum (Fn) through gene recombination technique with Escherichia coli (Ec) expression system, and to detect the immunogenicity and the immune effects of the recombinant protein on gingival tissues. Methods: The gene recombination technique and Ec expression system were used to express and purified the FomA protein. Totally 20 C57 mice were immuned with the protein or the phosphate buffer solution (PBS) buffer by subcutaneous injection (each 10 mice), and the specific FomA antibody was detection in mice serum. The immunogenicity of FomA protein was assessed by comparing the differences between groups. Furthermore, the model of mice gum abscess was constructed with Fn or Fn and Porphyromonas gingivalis (Pg) mixed suspension used the above mice. The score of the gingival abscess was recorded and the interleukin (IL)-1ß in gum tissue and mice serum was determined by enzyme-linked immunosorbent assay method, and the differences of the indexes between groups were compared to evaluate the effect of the FomA protein immunization. Results: Totally 1.0-1.5 g FomA protein were successfully obtained and the protein purity was over 90%. The FomA specific antibody was detected in the serum of mice by subcutaneous injection of the protein, and the antibody titer reached the highest level in 2 weeks after secondary immunization. The model of submaxillary gingival abscess was successfully constructed. In the Fn model, the score of the FomA protein immune group was (1.82±0.35), and the PBS control group was (2.62±0.71), with statistically significant difference between the two groups (P=0.049). In the Fn+Pg mixture model, the score of gingival abscess in the FomA immune group (2.31±0.55) was lower than that in PBS group (3.63±0.45), and the difference was statistically significant (P=0.003). Both in Fn and Fn+Pg injection group, the concentration of IL-1ß in the serum of FomA immune mice and gingival tissues was lower than that of PBS control mice (P<0.001). Conclusions: The recombinant FomA protein can be acquired by Ec expression system, and it can produce a certain level antibodies in the mice serum. The way of mice subcutaneously injected with the recombinant FomA protein can reduce the severity of periodontal infections caused by Fn and Pg.

Periodontitis: Consensus report of workgroup 2 of the 2017 World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions.

A new periodontitis classification scheme has been adopted, in which forms of the disease previously recognized as "chronic" or "aggressive" are now grouped under a single category ("periodontitis") and are further characterized based on a multi-dimensional staging and grading system. Staging is largely dependent upon the severity of disease at presentation as well as on the complexity of disease management, while grading provides supplemental information about biological features of the disease including a history-based analysis of the rate of periodontitis progression; assessment of the risk for further progression; analysis of possible poor outcomes of treatment; and assessment of the risk that the disease or its treatment may negatively affect the general health of the patient. Necrotizing periodontal diseases, whose characteristic clinical phenotype includes typical features (papilla necrosis, bleeding, and pain) and are associated with host immune response impairments, remain a distinct periodontitis category. Endodontic-periodontal lesions, defined by a pathological communication between the pulpal and periodontal tissues at a given tooth, occur in either an acute or a chronic form, and are classified according to signs and symptoms that have direct impact on their prognosis and treatment. Periodontal abscesses are defined as acute lesions characterized by localized accumulation of pus within the gingival wall of the periodontal pocket/sulcus, rapid tissue destruction and are associated with risk for systemic dissemination.